Problems after paying $2,000 for a head gasket job

[previagal]

Hello Everyone,
Can anyone help me understand what they did wrong? Drove the car home yesterday afternoon (and of course they're closed all weekend) and the overdrive light came on and stays on. Shift arm (used to shift from park to drive to reverse etc) has a foot of up and down slop/play even when in gear, and will not go into park every time. I had to start the car in neutral. Also, it is very hot inside the car now, the floor is really hot, more than normal/before the head gasket job. I let it sit for three hours (from 8pm to 11:20pm), and went out to check and floor and engine was still warm. I checked the oil, and the oil level on the dipstick appears to be 3" higher on the stick than the full mark, which I'm assuming is the area on the stick with the criss cross grid. I know the overdrive is somehow associated with the thermostat and the transmission, but the shift arm feels like they broke something inside. Or is it just not connected right? I'm at a loss here, and will have the van towed to the shop monday morning (overfilling the oil will blow the seals?) but I need to understand what they did wrong.
Can anyone shed light on these problems? Oh and the overdrive does work, push in for on, out for off, the light is just on all the time.

[cvtroger]

Sorry to hear that.

You should bring that back to them on monday!

Besides the overfilled oil, you said it was hot, was the engine temp high on the gauge cluster? Sounds like the messed up something when they dropped the motor (assuming they did).

[previagal]

Sorry to hear that.

You should bring that back to them on monday!

Besides the overfilled oil, you said it was hot, was the engine temp high on the gauge cluster? Sounds like the messed up something when they dropped the motor (assuming they did).

Bringing it back is a no-brainer. The temp gauge was not high, the INTERIOR of the car was hotter than normal, like really hot. I'm wondering what specifically they did wrong with the shifter.........why is the overdrive light on all the time now, etc.

[timsrv]

I've removed & installed Previa engines before without any such issues. It's hard for me to imagine what went wrong, but not everybody is as careful or observant as they should be. I'm guessing the shifter cable got yanked hard in the process, possibly breaking a stop in the column?

As for the heat issue, I would want to know the position of the heater valves as compared to the position of your control levers. Perhaps something was removed then oriented incorrectly upon installation? Do your heater knobs/levers feel normal through the range?

I'm not sure about your other issues, but if they have problems with a simple task like changing oil, I would worry about everything they touched. Adding oil is a simple job & the last step is verifying it displays correctly on the dipstick. When it comes to over servicing, doo-doo can happen, but if they checked the level they would have realized & rectified (pulling the drain plug to remove excess oil is about as basic as it gets).

Anyhow, it sounds like they botched the job. Previas are a bit sensitive regarding other things too (like special handling requirements with SADS), so I'd worry about possible damage there too. Was this a Toyota dealer or an independent? Did they use a Genuine Toyota head gasket or aftermarket?

Please keep us posted on the outcome. Tim

[previagal]

I've removed & installed Previa engines before without any such issues. It's hard for me to imagine what went wrong, but not everybody is as careful or observant as they should be. I'm guessing the shifter cable got yanked hard in the process, possibly breaking a stop in the column?

As for the heat issue, I would want to know the position of the heater valves as compared to the position of your control levers. Perhaps something was removed then oriented incorrectly upon installation? Do your heater knobs/levers feel normal through the range?

I'm not sure about your other issues, but if they have problems with a simple task like changing oil, I would worry about everything they touched. Adding oil is a simple job & the last step is verifying it displays correctly on the dipstick. When it comes to over servicing, doo-doo can happen, but if they checked the level they would have realized & rectified (pulling the drain plug to remove excess oil is about as basic as it gets).

Anyhow, it sounds like they botched the job. Previas are a bit sensitive regarding other things too (like special handling requirements with SADS), so I'd worry about possible damage there too. Was this a Toyota dealer or an independent? Did they use a Genuine Toyota head gasket or aftermarket?

Please keep us posted on the outcome. Tim

Thank you Tim........Here is the update.:clap:

turns out it was all very minor which is a big relief............

One of my theories was that the oil level sensor sucked extra oil into the case in error, which was what the mechanic thought happened also, because when he opened the hood and looked at the reservoir level, it was a quart and a half low, and when it left the shop, it had been filled to the full mark. The mechanic explained that there is a float inside/on the side of the oil pan, which due to the car sitting for several days without much oil in there, the float may have gotten stuck, so the sensor kept feeding oil into the case from the auxiliary oil reservoir. He told me to keep an eye on the reservoir level and if it starts losing oil, then the float may need to be replaced/disconnected. He also said he never checks the dip stick as his final step on an oil change that he’s done 20K times and that the excess oil probably would not have blown the seals, but the excess causes the engine to work a lot harder, because it is swimming in oil rather than just being lubricated with a thin layer on all the parts. He also checked the overdrive sensor for an error code and felt that the light may have come on because the shift cable was not adjusted correctly, so when the car was going 60mph the overdrive sensor couldn’t tell what gear it was in and the ECU sent an error message/blinking or solid overdrive light.

He could not explain the excessive heat in the passenger area, the heater knobs worked the way they should, and he felt the heater valves were all aligned correctly etc.

It took him about an hour to adjust the shift cable (now it works perfect, as before) drain the extra oil and refill the reservoir, but he said it was 2.5 quarts too much in the case, and it only took 1.5 quarts to make it the right level in the reservoir, so he wasn’t sure where the extra quart came from. I denied responsibility! LOL

Now the transmission clunks very slightly when it goes from reverse to drive and vice versa, and he wasn’t sure why that started happening, but mentioned a few possibles. The motor mounts do have a very small amount of play, where you can tweak them to line up the motor on the reinstall. Obviously this is not a lot, because otherwise the holes would not line up. But I don’t know how (a question I thought of after I left) this would change how the transmission engages, because my understanding is they dropped the engine and transmission as a unit, so why would that alignment even be off from motor mount tweaking?
The other possibility was that some time ago, I had to have the distributor replaced, with the Ridgeport aftermarket distributor. This job was done by my prior mechanic in the city I no longer live in. Not that that mechanic gave me the option of the OE part (probably because it was too expensive). When this mechanic took over the maintenance of my car, he noted on the aftermarket part, the two vent hoses that are normally there on the OE part, were not there, and where they went were open hose ends. He said that bugged him so when he did the reinstall, he looped the two ends together, which may have caused the engine to idle slightly faster, which would cause the slight clunk when the shifter went from reverse to drive and vice versa. He said in his opinion the car was not idling too fast, and I mentioned that perhaps what I was used to was it was idling too slow before, and now it’s idling normally, which was not what I was used to.

I asked him a few times during our conversation if repeated slightly clunking when it went into reverse or drive would make anything wear out faster and he didn’t answer that question.

I was in and out in an hour and a half, and the car runs good now, no shifting problems, I just need to keep an eye on the oil reservoir, and if it doesn’t lose oil, everything is probably simpatico.

Happy camper (so far) Maybe I can still take a mini vacation over labor day (had to cancel vacation scheduled for last week) if nothing else comes up with the car issues. if it’s going to come up, it should certainly come up within the next two weeks I would imagine...........

Thank you again for taking the time to consider my questions, it helped me a lot to put the problems in perspective and not worry so much.:wave2:

[TheMAN]

overfilled oil doesn't make the engine "work harder"... it causes it to get less lubrication because the oil gets churned up so much that the oil pump is sucking air.... this is called cavitation

the clunk could be coming from the U joints or diff... after so many miles, these things wear down and gets more slack

as for the heat inside the van, it could be lack of floor insulation... the access panels on the floor must be removed, and if the carpet's insulation was damaged or removed in some way, this could happen

[previagal]

overfilled oil doesn't make the engine "work harder"... it causes it to get less lubrication because the oil gets churned up so much that the oil pump is sucking air.... this is called cavitation

the clunk could be coming from the U joints or diff... after so many miles, these things wear down and gets more slack

as for the heat inside the van, it could be lack of floor insulation... the access panels on the floor must be removed, and if the carpet's insulation was damaged or removed in some way, this could happen

Thank you very much for taking the time to respond, here is some additional information........If the case is too full, the way the mechanic explained it is that the engine is "swimming" in oil so the pistons are working against a slight resistance, not just being lubricated; he said in extreme cases it can turn into foam and that's when it might start leaking, but not in ten miles which is all I drove the car after getting it back. I had it towed back to the mechanic yesterday morning because I was afraid of blowing the main seal, which turned out not to be soemthing I should have worried about.

Second, the description of all of the problems were with respect to the fact that they did not exist before the head gasket was done. The U joints and dif were not clunking before they did the head gasket. I've read in more than one place that if the engine is idling too fast, this can also be a reason, not necessarily due to wear in the differential or U joints. Some of these Previa rear ends have lasted 300K miles with regular maintenance, so honestly, that doesn't *seem* like it would be the reason, although again, I have no experience with the differentials failing on Previa beyond what I've read. I should say this is my 3rd Previa, and what failed on one of them was due to lack of maintenance, they had to replace the "3rd member." I just don't understand how people can drive cars for 120K miles and not do any maintenance, but they do.

As for the excess heat, I think it was just because it had way too much oil, all that oil got hot (it's just a theory), because after they fixed the shift cable (admitted it wasn't done right) and drained the excess oil, it did not feel as hot, and cooled down a lot faster last night after driving home. Previa doesn't have much insulation between the front seats and the motor, that's for sure.

I will ask the mechanic on the next oil change to check the U joints and gear oil in the differential though......I'm really trying to be proactive with all this stuff, because the older the car gets, the harder it might be to get parts. Toyota just doesn't support 20 years or older cars, they want you to buy a new one, which is not built even half as well as their older cars. My '96 4 Runner went almost 300K miles and all I did was brakes and all the maintenance. Nothing ever failed on that car, it was amazing. Oh, once I had to replace the igniter. That's about it. A new Toyota van is $40,000! Who can afford that except those people who choose to be enslaved on an ongoing basis servicing debt?

I did have the gear oil changed a while back, and checked that service record and it was changed 27, 617 miles ago. How often does that get changed? Some of the recommended intervals are confusing, like the dealer recommendation says change the oil every 7500, some shops put the windshield sticker at 4,000, some put it at 3,000, the car is 20 years old, are you supposed to change it more often the older it gets, or do they do that just to monitor whatever else needs replacing at that point?

Just want to thank everyone again for offering help in the way of information. Hope you are enjoying the summer van camping! :fshn:

[cvtroger]

@previagal,

Good to hear and I am sorry I wasn't much help! Regardless, for me at least, it is always good to know issues that arise.

[previagal]

Now the brake warning light in the dash is coming on, when I brake during driving and at random times while driving. It shuts off after several seconds when I release the brake pedal.
I just looked at the brake fluid reservoir and the level is about an inch above the minimum mark. When they did the brakes, the labor description says "remove and replace old brake fluid with new fluid in master cylinder and flush out entire system." I don't know if they filled the brake fluid and then bled the brakes and didn't check the level after that which is why it's low, or they messed something up while they were doing the brake job.

What could be wrong now? There's enough brake fluid in the reservoir, so that the light/sensor should not be coming on, is it possible that they pinched a brake line when they put the motor back in during the head gasket job? Or is this an issue with what this brake shop did? I don't trust them to take it back, without knowing what the problem is first.
Anyone have any ideas?

[TheMAN]

either the brake fluid was never filled full or it has leaked... that is the reason why the brake warning light came on... you need to figure out why

[previagal]

either the brake fluid was never filled full or it has leaked... that is the reason why the brake warning light came on... you need to figure out why


1877

[timsrv]

I just looked at the brake fluid reservoir and the level is about an inch above the minimum mark............

Perhaps I'm reading this wrong, but an inch above the minimum line is not low.............right? Or did you mean an inch below the minimum mark?

[timsrv]

Lol, on your sign. As some of you know I repair RV's for a living. Back in the 90's Camping World used to offer $10 installations on everything they sold. We used to have a sign in our shop that said "We fix $10 installations here" :LOL2: (and seriously, it wasn't a joke, we fixed a whole lot of $10 installations). When it comes to vehicle repairs it's usually better to go with the reputable shop & pay a bit more. Tim

[TheMAN]

Perhaps I'm reading this wrong, but an inch above the minimum line is not low.............right? Or did you mean an inch below the minimum mark?

she stated that the fluid level was an inch above the minimum mark... that doesn't mean the float won't drop enough to trip the light when you slam on the brakes... fluid gets pushed from the reservoir to the brake cylinders (pascal's law), and the weight shift also affects the angle of the fluid surface in the reservoir... I've seen this happen too many times... fluid level looks ok, but light comes on when brakes are used... owner scratches head.... cause: low brake fluid due to leaks or worn brake pads/shoes

[timsrv]

she stated that the fluid level was an inch above the minimum mark... that doesn't mean the float won't drop enough to trip the light when you slam on the brakes... fluid gets pushed from the reservoir to the brake cylinders (pascal's law), and the weight shift also affects the angle of the fluid surface in the reservoir... I've seen this happen too many times... fluid level looks ok, but light comes on when brakes are used... owner scratches head.... cause: low brake fluid due to leaks or worn brake pads/shoes

That's interesting because on my Previa 1" above the "min" line is also 1/4" above the "max" line. Does Pascal's law still apply when the unit is over serviced? :wnk:.

[previagal]

Perhaps I'm reading this wrong, but an inch above the minimum line is not low.............right? Or did you mean an inch below the minimum mark?

You're reading it right. That is what's so weird, the brake fluid level in the reservoir is at least an inch above the minimum line, so I wouldn't think that's low enough that the brake warning light keeps coming on and off. Which makes me wonder if something happened to the wiring when they put the motor back in.

[previagal]

That's interesting because on my Previa 1" above the "min" line is also 1/4" above the "max" line. Does Pascal's law still apply when the unit is over serviced? :wnk:.

my max line is about 3-4" above the min line. Mine is a 1994..........

[previagal]

she stated that the fluid level was an inch above the minimum mark... that doesn't mean the float won't drop enough to trip the light when you slam on the brakes... fluid gets pushed from the reservoir to the brake cylinders (pascal's law), and the weight shift also affects the angle of the fluid surface in the reservoir... I've seen this happen too many times... fluid level looks ok, but light comes on when brakes are used... owner scratches head.... cause: low brake fluid due to leaks or worn brake pads/shoes

I looked under the car, there's nothing on the ground. And just spent $668 for new front pads (rotors, brake lines, shim and clip kit etc.) They told me when they did the fronts, that the rears have about 20% left.

[previagal]

Lol, on your sign. As some of you know I repair RV's for a living. Back in the 90's Camping World used to offer $10 installations on everything they sold. We used to have a sign in our shop that said "We fix $10 installations here" :LOL2: (and seriously, it wasn't a joke, we fixed a whole lot of $10 installations). When it comes to vehicle repairs it's usually better to go with the reputable shop & pay a bit more. Tim

I thought I was doing that with the brake shop I went to. As far as paying a bit more, they charged me $668 for front brakes. They had good reviews on yelp, but way overcharged me, almost double on parts above retail pricing, and $160 labor to install 5 new brake lines, which took the tech 45 minutes total to take the old ones off and put the new ones on..... and the retail pricing on those parts means their wholesale pricing was less than half of what they charged me.

[timsrv]

Okay, I must have misunderstood. Thought you went with the cheaper independent shop. That really does seem to be a lot for a brake job. I'm so glad I don't have to rely on shops to do my work. As for the master cylinder, I guess I'm not familiar with the newer Previas. My newest one was a 93. They must have changed the master cylinder reservoir in 94. Still, a whole inch over min seems odd to be triggering a low level light. Does MR Pascal really drop the level 1" while braking? If putting more fluid in solves the problem then that's awesome. Too bad the shop you paid for this couldn't properly top off the reservoir.

Speaking of trusting others to do your work, when I started making enough $$$ to pay somebody else I decided to take my van to Toyota. It had started running bad & getting poor gas mileage. After 2 days they called and told me both the engine and transmission were bad (worn out) and needed to be rebuilt..........told me I could trade it in on one of their "quality used cars" for a lot less than the cost of repair. I said no thank you, picked it up, paid my bill, then went home and fixed it myself. A new TPS & a new o2 sensor + about 2 hrs labor solved my problem. Cost of me repairing was less than them telling me I needed another car. 15 years & another 100k miles later I'm still driving that same van. I did finally overhaul the engine (a couple months ago), but that same "worn out" transmission is still taking me down the road. The only thing I've done to it was change the ATF & strainer every 50k miles.

At this point in my life I really don't have the time or inclination to do my own vehicle work anymore, but what choice do I have? I took a chance & trusted 2 different places over the past 15 years (both were big disappointments). Hell, last year I took my Previa in for new tires, and the tire shop told me I needed new tie rods (was a lie). I bet they would have found a lot more too if I had believed them and let them do the work. At least I can still do my own work, so that's a good thing. It sucks being at the mercy of rip-offs & incompetence. Tim

[previagal]

Okay, I must have misunderstood. Thought you went with the cheaper independent shop. That really does seem to be a lot for a brake job. I'm so glad I don't have to rely on shops to do my work. As for the master cylinder, I guess I'm not familiar with the newer Previas. My newest one was a 93. They must have changed the master cylinder reservoir in 94. Still, a whole inch over min seems odd to be triggering a low level light. Does MR Pascal really drop the level 1" while braking? If putting more fluid in solves the problem then that's awesome. Too bad the shop you paid for this couldn't properly top off the reservoir.

Speaking of trusting others to do your work, when I started making enough $$$ to pay somebody else I decided to take my van to Toyota. It had started running bad & getting poor gas mileage. After 2 days they called and told me both the engine and transmission were bad (worn out) and needed to be rebuilt..........told me I could trade it in on one of their "quality used cars" for a lot less than the cost of repair. I said no thank you, picked it up, paid my bill, then went home and fixed it myself. A new TPS & a new o2 sensor + about 2 hrs labor solved my problem. Cost of me repairing was less than them telling me I needed another car. 15 years & another 100k miles later I'm still driving that same van. I did finally overhaul the engine (a couple months ago), but that same "worn out" transmission is still taking me down the road. The only thing I've done to it was change the ATF & strainer every 50k miles.

At this point in my life I really don't have the time or inclination to do my own vehicle work anymore, but what choice do I have? I took a chance & trusted 2 different places over the past 15 years (both were big disappointments). Hell, last year I took my Previa in for new tires, and the tire shop told me I needed new tie rods (was a lie). I bet they would have found a lot more too if I had believed them and let them do the work. At least I can still do my own work, so that's a good thing. It sucks being at the mercy of rip-offs & incompetence. Tim

I hear you loud and clear. I can't do my own work or believe me I would! Turns out the brake fluid just needed to be topped off, they checked everything, nothing wrong, and the light went out after they topped the fluid off.
Ihear you about the dealer too. They quoted me $3,000 for a head gasket job, can you imagine? I try really hard never to offend people/be rude, but I just couldn't help myself telling the service writer what a rip off I thought that was. The independent shop charged me $2K for the head gasket. The brake work was done by anothe small independent shop, and they really overcharged me. I guess it's just the cost of swimming with sharks.

Anyway, it's all good now.................car seems to be "missing" a little now though. I'm wondering if it's because the mechanic "looped" the hose from one outlet vent on the distributor to the other? This can really drive people crazy I'm sure. I'm just going to ignore it though, since it feels very slight, until the next oil change then bring it up, or it becomes really obvious. I missed my vacation, but am afraid to drive it any distance even for a weekend getaway, until all these bugs are resolved. Maybe it will adjust itself out. LOL:cnfsd:

[previagal]

Okay, I must have misunderstood. Thought you went with the cheaper independent shop. That really does seem to be a lot for a brake job. I'm so glad I don't have to rely on shops to do my work. As for the master cylinder, I guess I'm not familiar with the newer Previas. My newest one was a 93. They must have changed the master cylinder reservoir in 94. Still, a whole inch over min seems odd to be triggering a low level light. Does MR Pascal really drop the level 1" while braking? If putting more fluid in solves the problem then that's awesome. Too bad the shop you paid for this couldn't properly top off the reservoir.

Speaking of trusting others to do your work, when I started making enough $$$ to pay somebody else I decided to take my van to Toyota. It had started running bad & getting poor gas mileage. After 2 days they called and told me both the engine and transmission were bad (worn out) and needed to be rebuilt..........told me I could trade it in on one of their "quality used cars" for a lot less than the cost of repair. I said no thank you, picked it up, paid my bill, then went home and fixed it myself. A new TPS & a new o2 sensor + about 2 hrs labor solved my problem. Cost of me repairing was less than them telling me I needed another car. 15 years & another 100k miles later I'm still driving that same van. I did finally overhaul the engine (a couple months ago), but that same "worn out" transmission is still taking me down the road. The only thing I've done to it was change the ATF & strainer every 50k miles.

At this point in my life I really don't have the time or inclination to do my own vehicle work anymore, but what choice do I have? I took a chance & trusted 2 different places over the past 15 years (both were big disappointments). Hell, last year I took my Previa in for new tires, and the tire shop told me I needed new tie rods (was a lie). I bet they would have found a lot more too if I had believed them and let them do the work. At least I can still do my own work, so that's a good thing. It sucks being at the mercy of rip-offs & incompetence. Tim

Can I ask one more question? My prior mechanic had to replace the distributor, so he used an aftermarket Ridgeporter. The replacement didn't have the same hoses/outlets as the stock distributor. I don't quite understand what this recent mechanic meant when he said it bugged him that the two outlets had no connectors, so he just told me that when he did the head gasket, he "looped" them (whatever that means) and that on the OE distributors those outlets/hoses/? went into the air cleaner. At freeway speed, I don't know if I'm imagining it, but it feels like it's running *a little* rough, like there's a vacuum leak. I looked inside the hood tonight, to check and make sure the oil wasn't being pumped out of the reservoir, like it did when the float got stuck, because he told me to keep an eye on it, and there are threaded holes in the bottom of the hood compartment, where clearly something was unscrewed out of those holes and is missing. Does that have something to do with the mechanic "looping" the distributor hoses? What part went there, and should I make him put it back? I don't know why the h--- he did that, the car ran fine the way it was,not knowing what he did is bugging me, so he fixed it when it wasn't broken, and now there's an empty place there with threaded holes and I can see the ground, instead of what used to be there, and I don't even know what that part was, but there is definitely something missing. This flat empty metal strip with empty threaded holes is about six to eight inches wide and is below and just to the left of the oil reservoir. What part went there?-- the battery is on the right.

[timsrv]

Can I ask one more question? My prior mechanic had to replace the distributor, so he used an aftermarket Ridgeporter. The replacement didn't have the same hoses/outlets as the stock distributor. I don't quite understand what this recent mechanic meant when he said it bugged him that the two outlets had no connectors, so he just told me that when he did the head gasket, he "looped" them (whatever that means) and that on the OE distributors those outlets/hoses/? went into the air cleaner. At freeway speed, I don't know if I'm imagining it, but it feels like it's running *a little* rough, like there's a vacuum leak. I looked inside the hood tonight, to check and make sure the oil wasn't being pumped out of the reservoir, like it did when the float got stuck, because he told me to keep an eye on it, and there are threaded holes in the bottom of the hood compartment, where clearly something was unscrewed out of those holes and is missing. Does that have something to do with the mechanic "looping" the distributor hoses? What part went there, and should I make him put it back? I don't know why the h--- he did that, the car ran fine the way it was,not knowing what he did is bugging me, so he fixed it when it wasn't broken, and now there's an empty place there with threaded holes and I can see the ground, instead of what used to be there, and I don't even know what that part was, but there is definitely something missing. This flat empty metal strip with empty threaded holes is about six to eight inches wide and is below and just to the left of the oil reservoir. What part went there?-- the battery is on the right.

I'm not sure on a 94, but this is where the anti-lock brake actuator is on my Previa. Can you post a picture of the area in question? Your question on the distributor doesn't ring any bells either. I've only had experience with Toyota distributors on Previas. Perhaps "the man" will have an idea what's going on. Tim

[previagal]

I'm not sure on a 94, but this is where the anti-lock brake actuator is on my Previa. Can you post a picture of the area in question? Your question on the distributor doesn't ring any bells either. I've only had experience with Toyota distributors on Previas. Perhaps "the man" will have an idea what's going on. Tim

Thanks, I will take a picture tomorrow. One thing that occurs to me, the more I drive it, is there is a lot more vibration in the front end/steering wheel, than before the head gasket job. At a constant speed of 50-55 mph, it feels like there is a vacuum leak, or it's "missing" a little. There is also the vibration. I can't tell if the "missing feeling" is due to the reason for the vibration, or there are two separate issues. One thing occurred to me after driving it more, is when I first purchased the car, it had the infamous SAD locomotive sound. I took it to a driveline shop who replaced the bushings. That was at 139,617. The van now has 167,007 miles. I've read in a few places, if the SAD is disconnected (like I'm assuming they did when they dropped the engine and trans as a unit to do the headgasket job) that when it is reconnected, it has to be bolted back in at the same "clock position" or it will be out of balance. I'm wondering if it wasn't bolted back in properly and that is why there is so much vibration in the steering wheel? In one of your earlier replies, you mentioned the SAD needed "special handling" or it could be damaged, when they did the head gasket job. What kind of special handling were you talking about, and what kind of damage could occur if they didn't do it correctly? This stuff is starting to drive me crazy. :cnfsd:
The other feeling is the "missing" feeling, which I can feel in the seat. Do you think both could be attributed to the SAD not being bolted back in at the original position?
I sure appreciate your replies, you just have no idea. Today I got on fleaBay, the 1994 factory service manual and the supplement for fifty bucks. At least I can see what the heck is going on with all these parts, even if I can't do any work myself, I won't be completely ignorant.
Also, I asked him about the "looping" thing, and I guess he looped the two fittings with one hose where (he said) the OE distributor would have been connected to the air filter with those two fittings. The Ridgeporter replacement did not have the fittings to connect to the air filter, so there were just two hoses on the air cleaner hanging there, which I guess that's what he meant when he said he looped them and said "this is better" than having two hoses hanging there, which "bugged" him.

[timsrv]

The SADS is balanced as an assembly, so anytime it's taken apart it should be marked and reassembled the same as before. Another thing that's important is not allowing the rubber insulators to rotate during reassembly (while tightening the bolts). These things are mentioned in the service bulletin I'm attaching to this post. Another thing that can mess one up is allowing it to hang unsupported (particularly the engine side). When an end is disconnected the shaft needs to be supported. This can be accomplished by using a wire coat hanger or something similar to keep it straight. Whatever the method, the object is to prevent side stress on the flex couplers.

When the Previa was still in production & for about 5 - 10 years after, most mechanics at most Toyota dealerships were trained on this and knew how to handle SADS. Now that the Previas are aging very few make it back to the dealer for service. As a result very few techs have experience with them (and that's the dealer). When it comes to independent shops, it's not very likely that many of these techs EVER learned about proper handling (much less likely now that it's been 17 years since the last Previa rolled off the line).

I'm probably going to catch some crap for saying this, but after years of experience in this field these are my thoughts. There are some techs who are very conscientious and very well trained. Unfortunately this is not the norm. When you consider the pay grade & working conditions for auto mechanics, it makes you wonder why any intelligent person with an aptitude for this sort of thing would choose wrenching as a profession. The sad fact is most "quality" people choose something else. This leaves drop-outs, druggies, and other "less than optimal" choices for shops to hire. I'm not saying these guys are all this way, I'm just saying it's a challenge for shops to fill their tech positions with quality employees. Some of these "techs" don't care, some do the best with the skills they possess, and some are just damn crooks. The best techs tend to gravitate to the jobs that pay the most (i.e. shops that charge the most). The not so good end up working for the independents & cut rate shops. This is the reason most people buy new or newer cars after a major component fails. Most of these shops can "fumble" their way through repairs on standard vehicles, but when you throw them a "curve ball" (something unique or unusual) they usually don't do so well. :dizzy: :doh: :wall: Tim

[previagal]

The SADS is balanced as an assembly, so anytime it's taken apart it should be marked and reassembled the same as before. Another thing that's important is not allowing the rubber insulators to rotate during reassembly (while tightening the bolts). These things are mentioned in the service bulletin I'm attaching to this post. Another thing that can mess one up is allowing it to hang unsupported (particularly the engine side). When an end is disconnected the shaft needs to be supported. This can be accomplished by using a wire coat hanger or something similar to keep it straight. Whatever the method, the object is to prevent side stress on the flex couplers.

When the Previa was still in production & for about 5 - 10 years after, most mechanics at most Toyota dealerships were trained on this and knew how to handle SADS. Now that the Previas are aging very few make it back to the dealer for service. As a result very few techs have experience with them (and that's the dealer). When it comes to independent shops, it's not very likely that many of these techs EVER learned about proper handling (much less likely now that it's been 17 years since the last Previa rolled off the line).

I'm probably going to catch some crap for saying this, but after years of experience in this field these are my thoughts. There are some techs who are very conscientious and very well trained. Unfortunately this is not the norm. When you consider the pay grade & working conditions for auto mechanics, it makes you wonder why any intelligent person with an aptitude for this sort of thing would choose wrenching as a profession. The sad fact is most "quality" people choose something else. This leaves drop-outs, druggies, and other "less than optimal" choices for shops to hire. I'm not saying these guys are all this way, I'm just saying it's a challenge for shops to fill their tech positions with quality employees. Some of these "techs" don't care, some do the best with the skills they possess, and some are just damn crooks. The best techs tend to gravitate to the jobs that pay the most (i.e. shops that charge the most). The not so good end up working for the independents & cut rate shops. This is the reason most people buy new or newer cars after a major component fails. Most of these shops can "fumble" their way through repairs on standard vehicles, but when you throw them a "curve ball" (something unique or unusual) they usually don't do so well. :dizzy: :doh: :wall: Tim

In my years of having to be at the mercy of mechanics, I totally agree. I try to research this stuff, so I can discuss intelligently, but if I approach something like this with "did you do it this way?" they get mad and tell me to go somewhere else. Anyway if the mechanic did mess up the SAD, this is really depressing, because I spent a lot of money less than 30K miles ago having it rebuilt by a driveline shop. :o( Once it's messed up, then do they have to replace those couplers again? This vibration driving locally isn't so bad, but on the freeway after even a half hour, it's very wearing. Anyway, here are the photos of the place where it *seems* like they forgot to put something back. This is some days after getting the car back, so some dirt is in those threads now, but when I first got it back, they were clean as a whistle. You can see how the lower portion of the threads shows dirt/rust, the upper portion looks clean, like something was newly removed.

[timsrv]

That is the location where the ABS actuator is mounted. Does (or should I say "did") your van have anti-lock brakes? Seems unlikely this would have been removed as it would be like opening a can of worms. There would need to be rerouting of brake lines, and other major issues. Labor to convert an ABS system to a non-ABS system would be high and not worth the trouble........even if he had a donor vehicle to swap parts with and a buyer for the parts taken. Perhaps he spilled something here and cleaning it up made it look as though there was something previously installed???

Not sure what to tell you regarding your other issues. Vibrations can be tough to chase down. Process of elimination is usually how it's done (checking the balance of one item at a time). Since yours is a RWD, this narrows it down quite a bit. The poor man's way of checking balance of a shaft is to hold the RPM at a point when the vibrations are the worst, then use a piece of chalk to carefully touch the spinning shaft. Safety is a major concern when performing such an operation, so do so at your own risk. Access is also an issue & it would need to be done from under the vehicle.

Once the chalk has been applied, the vehicle is stopped and the chalk mark is checked. If the chalk is heavier on one side than the other, or if there's only a mark on one side of the shaft, then the shaft is likely out of balance. The shaft can be balanced by installing one or more stainless hose clamps on the shaft and putting the screw side (heavy side) on the side of the shaft where the chalk was light or not present. Check for vibrations again and repeat the chalk application/balancing procedure until the vibration is gone.

I'm sure it goes without saying that this is a crude way to balance a shaft, but I've used it before and it does work. Tim

[previagal]

That is the location where the ABS actuator is mounted. Does (or should I say "did") your van have anti-lock brakes? Seems unlikely this would have been removed as it would be like opening a can of worms. There would need to be rerouting of brake lines, and other major issues. Labor to convert an ABS system to a non-ABS system would be high and not worth the trouble........even if he had a donor vehicle to swap parts with and a buyer for the parts taken. Perhaps he spilled something here and cleaning it up made it look as though there was something previously installed???

Not sure what to tell you regarding your other issues. Vibrations can be tough to chase down. Process of elimination is usually how it's done (checking the balance of one item at a time). Since yours is a RWD, this narrows it down quite a bit. The poor man's way of checking balance of a shaft is to hold the RPM at a point when the vibrations are the worst, then use a piece of chalk to carefully touch the spinning shaft. Safety is a major concern when performing such an operation, so do so at your own risk. Access is also an issue & it would need to be done from under the vehicle.

Once the chalk has been applied, the vehicle is stopped and the chalk mark is checked. If the chalk is heavier on one side than the other, or if there's only a mark on one side of the shaft, then the shaft is likely out of balance. The shaft can be balanced by installing one or more stainless hose clamps on the shaft and putting the screw side (heavy side) on the side of the shaft where the chalk was light or not present. Check for vibrations again and repeat the chalk application/balancing procedure until the vibration is gone.

I'm sure it goes without saying that this is a crude way to balance a shaft, but I've used it before and it does work. Tim

Wouldn't I be able to tell if the ABS actuator was gone --wouldn't the brakes malfunction?

Also, if the shaft is out of balance, and was in balance before the head gasket, wouldn't it be out of balance due to being bolted back in not in the original clock position? So wouldn't they be able to mitigate the problem by unbolting it and finding out/trying bolting it back in where it should have gone? Also, will it damage the couplers, if I drive it out of balance? I would imagine so.
What a retarded design this front shaft was.

[timsrv]

Wouldn't I be able to tell if the ABS actuator was gone --wouldn't the brakes malfunction?

Yes, that's why I was thinking you never had anti-lock brakes............and perhaps the tech just cleaned a spot there, making it appear there was something previously there.


Also, if the shaft is out of balance, and was in balance before the head gasket, wouldn't it be out of balance due to being bolted back in not in the original clock position? So wouldn't they be able to mitigate the problem by unbolting it and finding out/trying bolting it back in where it should have gone?

Yes, but we're not even sure this is where the vibration is coming from, although it stands to reason since it was recently messed with. They could experiment by trying different locations to mount, but the chalk thing could help determine if it's even the SADS or help verify if/when they get it back into the correct position. Was simply a suggestion. Although probably not the best course of action, it's an alternative to spending $$$ at a shop with specialized balancing equipment.


Also, will it damage the couplers, if I drive it out of balance? I would imagine so.

Yes, aside from being annoying, much more stress is put on components when they are out of balance.


What a retarded design this front shaft was.

It's actually impressive that these typically last well over 150k miles. If handled correctly they can be repaired and go another 150k + miles. Too bad they couldn't have made them idiot proof. As a former aircraft mechanic (helicopters) I can tell you there are several things like this that survive countless hrs of use with excellent service records. It's all about following procedures and knowing how to handle these things. Something a lot of automotive "techs" just can't wrap their heads around. Tim

[previagal]

Yes, that's why I was thinking you never had anti-lock brakes............and perhaps the tech just cleaned a spot there, making it appear there was something previously there.



Yes, but we're not even sure this is where the vibration is coming from, although it stands to reason since it was recently messed with. They could experiment by trying different locations to mount, but the chalk thing could help determine if it's even the SADS or help verify if/when they get it back into the correct position. Was simply a suggestion. Although probably not the best course of action, it's an alternative to spending $$$ at a shop with specialized balancing equipment.



Yes, aside from being annoying, much more stress is put on components when they are out of balance.



It's actually impressive that these typically last well over 150k miles. If handled correctly they can be repaired and go another 150k + miles. Too bad they couldn't have made them idiot proof. As a former aircraft mechanic (helicopters) I can tell you there are several things like this that survive countless hrs of use with excellent service records. It's all about following procedures and knowing how to handle these things. Something a lot of automotive "techs" just can't wrap their heads around. Tim

If they're going to design something like that, they should design it so that putting it back doesn't require an engineering degree or 40 years experience. It's not realistic to think people are going to understand things on that level, without going to Toyota school, and even then, like you said, the techs now don't even know how to work on it. That's what I meant by retarded. No one knows how to put them back, shops do not even want to do the bushing job because of that, they don't have the equipment to balance them etc, so seems like an impractical design.
What do you think about this? I have half a mind to just buy one, and drive the car until this one fails again, and then have a driveline shop install this one:
http://www.coloradodriveshaft.com/toyota_previa.htm

It's just so annoying driving any distance with vibration coming up through the gas pedal and the steering wheel. The "miss" feeling I feel through the seat.

[timsrv]

What do you think about this? I have half a mind to just buy one, and drive the car until this one fails again, and then have a driveline shop install this one:
http://www.coloradodriveshaft.com/toyota_previa.htm

It sounds good and I'm sure it would be balanced well. My question would be regarding the "OEM style" parts & how long they will last. I know there are OEM style parts out there that do not last, just don't know how these measure up regarding quality.

A few years back there was a guy on eBay selling OEM shafts complete for $68 each. I bought 11 of them & then sold for $350 - $500 each. I probably should have bought more and hung onto them. I see now these OEM ones listed on eBay for up to $1,600 each (do people seriously pay that much?). One guy has a rusty old one he's asking over $1k for. He says it's new (never installed) and it's rusty due to sitting in his shop since 1996. Man, what a racket these things are. If I need to visit this issue again I'm going to purchase new couplers from Toyota, install them on a salvage yard shaft, then have the assembled shaft balanced by a drive-line shop (I'll be standing there watching them like a hawk). Good luck with whatever you decide. Tim

[previagal]

It sounds good and I'm sure it would be balanced well. My question would be regarding the "OEM style" parts & how long they will last. I know there are OEM style parts out there that do not last, just don't know how these measure up regarding quality.

A few years back there was a guy on eBay selling OEM shafts complete for $68 each. I bought 11 of them & then sold for $350 - $500 each. I probably should have bought more and hung onto them. I see now these OEM ones listed on eBay for up to $1,600 each (do people seriously pay that much?). One guy has a rusty old one he's asking over $1k for. He says it's new (never installed) and it's rusty due to sitting in his shop since 1996. Man, what a racket these things are. If I need to visit this issue again I'm going to purchase new couplers from Toyota, install them on a salvage yard shaft, then have the assembled shaft balanced by a drive-line shop (I'll be standing there watching them like a hawk). Good luck with whatever you decide. Tim

Took it to the driveline shop this morning, who did the original drive shaft and the front SAD when I first bought the car. They drove it and said the problem is definitely the SAD. Took it apart and told me the couplers were cracked on both the engine side as well as the non engine side. I asked if this could have happened if the mechanic who did the head gasket overtightened it on the engine side, and let it hang on the non-engine side, and they said "it's possible." I can't imagine they cracked it on both sides, just from not realigning it properly when they reinstalled it and the mechanic told me he'd done 20 previa head gaskets, so I can't imagine he overtightened it. Even I know how to not do that. The tech bulletin you posted (THANK YOU) shows the bolts should be tightened to a specific torque, and make sure not to twist the rubber bushings when reconnecting. I just cant imagine my mechanic caused all this damage. the shop told me the "inserts are flexible" but the tech bulletin doesn't talk about inserts at all. Is the shop calling the flexible coupler the insert?
Also, what i don't understand is, people talk about urethane couplers, and aluminum couplers. How can an aluminum coupler be "flexible"? which is how the tech bulletin describes it? Isn't this why they say flexible coupler, because it's rubber/something flexible, which aluminum is not?
I asked the shop to save the old parts so I can better understand what happened. Hopefully, I'll never have to do this again as long as I own the car.
Thank you again Tim for taking the time to answer all my questions.

[timsrv]

The body of the OEM couplers is aluminum. The points where it attaches are separate bushings attached to the aluminum housing via vulcanized rubber. The urethane ones are entirely molded urethane with the bushings cast into them. We discussed this recently in THIS THREAD (http://www.toyotavantech.com/forum/showthread.php?2075-Some-Previa-questions). The part you want starts with post #15. pdgizwiz makes some good points regarding the differences between OEM & urethane styles. Tim

[timsrv]

I should mention to use the search feature here (upper right corner) using the term SADS. There are several discussions on the subject. I know the other thread shows the urethane couplers, here's a thread that shows the factory ones and the differences between 91 - 93 vs 94 & up:

http://www.toyotavantech.com/forum/showthread.php?1826-changing-flexibole-compling-on-previa-93

[previagal]

Thank you, I recall after reading it again just now that I had at some time in the past read the other thread that starts out with the questions about the seats, then talks about the SAD coupler kits and your comment about how your experience with the ebay urethane replacement wasn't good, but you are recommending this one on ebay that is Polyurethane? The shop who is doing the fix on my car said they use the aluminum ones.Also, the production date on my car is 8/93 and the dealer OE coupler kit starts at production date 1/94. So I'm not sure the one on ebay listed from 94-97 would fit my car, or be for the newer shaft

[timsrv]

Thank you, I recall after reading it again just now that I had at some time in the past read the other thread that starts out with the questions about the seats, then talks about the SAD coupler kits and your comment about how your experience with the ebay urethane replacement wasn't good, but you are recommending this one on ebay that is Polyurethane? The shop who is doing the fix on my car said they use the aluminum ones.Also, the production date on my car is 8/93 and the dealer OE coupler kit starts at production date 1/94. So I'm not sure the one on ebay listed from 94-97 would fit my car, or be for the newer shaft

You might want to read my post again. I don't recommend the urethane ones nor have I ever. I did try them but the jury is still out on lifespan (I suspect they are failing). I did suggest the Febest OEM style ones in that 1st thread I linked you to, but also stated I know nothing about them (other than what Amazon users posted about some of their other products). Personally, after my experiences, I would only recommend OEM Toyota couplers, but encourage others to experiment in the hopes somebody will stumble upon a good substitute of comparable quality to the overpriced Toyota couplers. Tim

[timsrv]

Another thing that makes comparison of these parts hard to verify is installation. It's impossible to know if these are being installed correctly, so it's possible some of the AM couplers are getting a bad wrap due to improper installation. Tim

[previagal]

What it sounds like from all of your posts about the after-market couplers for 91-93 is they don't hold up well, and your suggestion to get a 94 shaft from a wrecking yard and put the OE kit on there is not realistic for me. The shops aren't going to do that, so I'm sort of stuck with their procedures. However, I am going to take a chance on the ebay coupler, I hope it's not the same one you bought, because the photo in the one on post #15, looks like a much better part than what you're describing.

[previagal]

You might want to read my post again. I don't recommend the urethane ones nor have I ever. I did try them but the jury is still out on lifespan (I suspect they are failing). I did suggest the Febest OEM style ones in that 1st thread I linked you to, but also stated I know nothing about them (other than what Amazon users posted about some of their other products). Personally, after my experiences, I would only recommend OEM Toyota couplers, but encourage others to experiment in the hopes somebody will stumble upon a good substitute of comparable quality to the overpriced Toyota couplers. Tim

You wrote: "The part you want starts with post #15" This sounded like a recommendation, but it's no biggie, I take full responsibility for making this decision, I didn't do it just on that comment. I'd read in several places that the aluminum ones don't hold up, and the OE part I found out, is not available for my car because the production date is 8/93 and it takes the smaller size. So this is an experiment. If they don't last, they don't last, then I'll go to a wrecking yard and get the 94 shaft, the OE couplers and go from there. I might just buy a set of the OE couplers now, because in a year or so, they might not even be available anymore. I can't quit now, I have so much invested in this car. But here are the reviews I went with, which granted since they are both from this year, the jury is still out on the longevity but it doesn't sound like they had any vibration issues, which is what the shop explained is the tradeoff with urethane. Also there are a lot more reviews on the aluminum ones, that say they only lasted one or two years, and the two years ones people thought were good. How can this be good if the originals last 150K?

[previagal]

You might want to read my post again. I don't recommend the urethane ones nor have I ever. I did try them but the jury is still out on lifespan (I suspect they are failing). I did suggest the Febest OEM style ones in that 1st thread I linked you to, but also stated I know nothing about them (other than what Amazon users posted about some of their other products). Personally, after my experiences, I would only recommend OEM Toyota couplers, but encourage others to experiment in the hopes somebody will stumble upon a good substitute of comparable quality to the overpriced Toyota couplers. Tim

Ok, I just need to ask, it's still not too late to go with the aluminum ones. I read your posts further down about the urethane ones you got off of ebay. The first time I read it, I ASSumed there was more than one product available, and the ones you got were a different brand than the urethane ones the poster showed on #15 because you said the ones you got looked a lot worse than the ones in the picture of the PBS parts. Can you tell me if the ones you got off of Ebay are the exact same brand as the poster shows on #15? Which are the ones I ordered and which are these: http://www.ebay.com/itm/Toyota-Previa-Auxiliary-Drive-Shaft-Coupling-Kit-91-93-524-/221410982853

It says "lifetime warranty", and is a company called PSB (Problem Solving Bushings) from Armstrong Distribution. And also, I researched the Febest part, the equivalent part number is the same part the dealer is telling me is for 94 and newer and won't fit on my driveshaft. Either way it seems like the earlier model aluminum ones don't hold up, and the urethane ones ma or may not hold up better, it's so hard to know. Like you said, a lot depends on the installation.I guess even with a lifetime warranty and they fall apart fast, who wants the replacement?

[TheMAN]

just get a proper 94+ SADS and then get a coupler kit from the dealer and use those.... I remember spending big bucks on replacing the entire SADS to a 94 version and I haven't regretted it since... it works very well and lasted many trouble free miles so far!
*knocks on wood*

none of those aftermarket kits for the 91-93 shafts are worth a crap

[timsrv]

You wrote: "The part you want starts with post #15" This sounded like a recommendation

Sorry, I meant the part of that thread you want to read starts at post #15. I wasn't talking about the actual "part part" lol, sorry if that was/is confusing.........:dizzy: :doh:

[timsrv]

Can you tell me if the ones you got off of Ebay are the exact same brand as the poster shows on #15? Which are the ones I ordered and which are these: http://www.ebay.com/itm/Toyota-Previa-Auxiliary-Drive-Shaft-Coupling-Kit-91-93-524-/221410982853

I got mine in January of 2010. I don't remember the seller, but I snapped a couple pics of the bushings and the part number on the side of the box. Here is what I got:

http://i8.photobucket.com/albums/a23/timsrv/IMG_0554.jpg

http://i8.photobucket.com/albums/a23/timsrv/IMG_0550.jpg

If you look in the "item specifics" section of your eBay listing, you will see:

Manufacturer Part Number:
ADUS 524

[previagal]

Sorry, I meant the part of that thread you want to read starts at post #15. I wasn't talking about the actual "part part" lol, sorry if that was/is confusing.........:dizzy: :doh:

Well, I ended up getting the urethane coupler kit based on that, but again, it's ok, I made the decision and even the urethane has to last a whle, probably longer than the aluminum ones which on my car only lasted 29K miles (I'm thinking it must have been on it's way out before they did the head gasket job, that or the driveshaft shop is giving me the shaft telling me both ends were badly cracked, in which case *I think* the vibration had to be much worse than it actually was), however, I've decided based on all I'vre read on here, to buy an OE coupler kit ($278 out the door from the dealer) and try to find a used 95 or newer driveshaft, per MrMan and everyone else's opinion. At this point, it looks like I'm going to be stuck with the urethane job this time around, because I have been calling around trying to find the actual shaft assembly from these Toy wrecking yards, and they keep trying to sell me the aftermarket bushing kit and telling me that's all I need. I've explained so many times why I need the 95 or newer shaft "assembly", and they don't get it. Primarily because my car is a 94 but production date 8/93 and it definitely has the smaller bolt size. I don't know if they made any 94s after 8/93, but they must have because the newer OE coupling kit is sold as described by the dealer for 94-97. Trying to first explain why I don't want to buy a coupling kit and then trying to tell them the production date of the salvage car has to be 1/94 or newer, it's so frustrating. If anyone happens to come across the newer drive shaft (I'd say safely if it's from a 95 or newer Previa - no risk of them sending the wrong part), please let me know. I'm going to buy the newer dealer coupling kit and just keep it in my stash, and continue to search for the newer driveshaft. So in another 30K or whatever when the urethane one is pulverized, I can just go somewhere and have them install the upgrade. Maybe the dealer, these other shops are getting to be as big a rip off as the dealer. Telling me "two hour minimum" to diagnose the vibration.

[previagal]

I got mine in January of 2010. I don't remember the seller, but I snapped a couple pics of the bushings and the part number on the side of the box. Here is what I got:

http://i8.photobucket.com/albums/a23/timsrv/IMG_0554.jpg

http://i8.photobucket.com/albums/a23/timsrv/IMG_0550.jpg

If you look in the "item specifics" section of your eBay listing, you will see:

Manufacturer Part Number:
ADUS 524

Yep, that is what I got. :o( However, you bought it in 2010 so it lasted 4 years? So do you think what wears on this is the insert (cracks) or the urethane becomes sloppy?
If mine lasts 16K miles, that's long enough to find the other upgrade/95 or newer shaft. But that's not very much miles. maybe a year and a half for me. Which is about how long the aluminum ones lasted.
I'm getting burned out on this! LOL

[previagal]

just get a proper 94+ SADS and then get a coupler kit from the dealer and use those.... I remember spending big bucks on replacing the entire SADS to a 94 version and I haven't regretted it since... it works very well and lasted many trouble free miles so far!
*knocks on wood*

none of those aftermarket kits for the 91-93 shafts are worth a crap

Thank you. If I could find one of those shafts, I'd do that. But after calling all the Toyota wrecking yards in the area, I've had no luck.
And you have to be careful about saying 94+ because my car is a 94, but the production date is 8/93 and it has the old style smaller bolt holes. Has to be a production date of 1/94 or newer. I wish I'd known about this before I bought the car, but that's how it goes sometimes. The newer shaft with OE coupler kit is the proper fix, just have to find a used shaft.

[TheMAN]

car-part.com is your friend
pick the year, and choose driveshaft... it should then let you select "equipment driveshaft" once you clicked "search"
there's some that could be had for a couple of bills

[previagal]

car-part.com is your friend
pick the year, and choose driveshaft... it should then let you select "equipment driveshaft" once you clicked "search"
there's some that could be had for a couple of bills

I went that route too. All of them are in places like Georgia, Ohio etc. Have you ever bought one like that, because I don't trust them sending the right part. And the only automotive thing I ever bought from Ohio was a car that was completely rusted out/bondoed (they salt the roads there, everything rusts.) Got hosed royally on that deal, and it was not repairable.

[timsrv]

Yep, that is what I got. :o( However, you bought it in 2010 so it lasted 4 years? So do you think what wears on this is the insert (cracks) or the urethane becomes sloppy?
If mine lasts 16K miles, that's long enough to find the other upgrade/95 or newer shaft. But that's not very much miles. maybe a year and a half for me. Which is about how long the aluminum ones lasted.
I'm getting burned out on this! LOL

I don't drive that Previa much. Since I put these on in Jan 2010 I've driven a total of 16,173 miles. The last couple thousand miles I've noticed a vibration that's getting gradually worse. I need to go check the bushings as I think these are likely the reason, but haven't gotten around to it yet (sorry). And sorry about the misunderstanding with my post. I was trying to save you the time of reading the 1st 14 unrelated posts. In my defense I find it hard to imagine anybody reading my comments (regarding these urethane bushings) and taking them as an endorsement. Tim

[previagal]

I don't drive that Previa much. Since I put these on in Jan 2010 I've driven a total of 16,173 miles. The last couple thousand miles I've noticed a vibration that's getting gradually worse. I need to go check the bushings as I think these are likely the reason, but haven't gotten around to it yet (sorry). And sorry about the misunderstanding with my post. I was trying to save you the time of reading the 1st 14 unrelated posts. In my defense I find it hard to imagine anybody reading my comments (regarding these urethane bushings) and taking them as an endorsement. Tim

Update as of 8-27. I called the shop and asked them to go forward with the aluminum parts. Will return the urethane ones. Have located newer shaft and found OE coupler kit for $232 with free shipping from a dealer in Phoenix.
All is well, but what a head trip! I sure learned a lot in the past two days though, thank you for all your replies.

[TheMAN]

I went that route too. All of them are in places like Georgia, Ohio etc. Have you ever bought one like that, because I don't trust them sending the right part. And the only automotive thing I ever bought from Ohio was a car that was completely rusted out/bondoed (they salt the roads there, everything rusts.) Got hosed royally on that deal, and it was not repairable.

I bought stuff like brakes and ECUs from various different junk yards via car-part.com before... never had a problem... it's all about asking the right questions and telling them things they want to hear
plus it's paid for by credit card anyway... if they tried to screw me, I'd just dispute the charges

there's no sense being paranoid about buying things online or over the phone... stuff going wrong inevitably happens from time to time... the chances of it happening is just about the same as buying local

[previagal]

car-part.com is your friend
pick the year, and choose driveshaft... it should then let you select "equipment driveshaft" once you clicked "search"
there's some that could be had for a couple of bills

I actually did find a couple from that website last night, one in AZ and one in the bay area (I"m in southern CA) thanks for that website. Also, if anyone is interested, I found the OE Coupling kit at Camelback Toyota-Scion for $232 free Shipping. Which is a lot less than the $232 they charge plus one site said $31 shipping, which is a rip off.
Here is the link for the coupling kit part http://parts.camelbacktoyota.com/shoppingcart/index.cfm?siteid=214329&retVal=%2Fparts%2Findex.cfm%3Faction%3DoePartSearc h%26siteid%3D214329%26make%3DToyota%26year%3D%26mo del%3D%26submodel%3D%26searchText%3D0437428011

There are two part numbers, the dealer told me 0437428011 supercedes 0437428010, but it's the same part. Heck, how many of these could there be, this is the one!

[TheMAN]

04374-28011 supersedes 04374-28010, but either kit works.... who cares? :)
buy from out of state and pay no taxes ;)

[previagal]

Who cares? :) It's not "either kit" as previously posted, both numbers are the same part. That information was intended as a contribution as well as the link for the OE coupler for $232 with free shipping, because not everyone on these forums is an expert, some of us come in here to learn, so maybe someone could use that information is all. You may also have noticed that I posted the OE coupler source from a dealer in Arizona, I've been savvy about buying out of state for over ten years, which is about how long I've been buying and selling online.

But to "explain" my (well thought out) reasons for buying locally in CA, has nothing to do with being "paranoid". The shipping amount from an out of state seller where these other shafts are (east coast states, south east, florida etc), would probably exceed the sales tax and more importantly, if I buy locally I'd get it much faster. I don't have another car to use so every day I have to wait, which always turns into a week or more for a part to come from Georgia, or Ohio or Florida,or Maryland or who knows where, I have NO transportation which is critical for me to work and earn money. Of course I can rent a car, however add that cost onto $50-60 for cross country shipping for one of these shafts that amount is also going to exceed sales tax. Getting these parts faster than "UPS ground" which is 4-5 full business days from all of those states is important. Not to mention, if there IS something wrong with a shaft I buy locally, I can take it back for a refund, instead of spending another 50-60 bucks of sunk cost to ship it back to BF Egypt and *hope* they give me a refund instead of saying I damaged it on my end. :) Anyway, I'm sure everyone is sick of this topic, I know I am, and all I can say is, THANK YOU for all of the information, I learned a lot!

[previagal]

One of the main problems with this is no independent shops have the tooling to correctly balance the shaft when they replace the couplers. Most of them won't even take the job because as it was explained to me, they can't put out a decent job because of this reason. So getting a newer shaft from a wrecking yard and using OE couplers, still have the vibration problem, due to whoever is installing it not being able to balance the shaft. As an update after having the only shop who would take the job, install the aluminum couplers, they quoted me $491 for the job and then when I got the bill it was $50 higher. :dizzy: And it vibrates worse at lower speeds now than it did before I took it there. I'm so frustrated with this issue because I'm not a mechanic and am at the mercy of the sharks. Like the couplers they installed they had it listed on the invoice as individual couplers, for $86 each, and these couplers are sold as a set, all over the web for $50-65 for the set of two. My next question is, does the shaft have to be balanced before these aluminum couplers are installed, like they strongly emphasize with the urethane couplers? I'm thinking I might call the dealer and see what they would charge to take the stupid thing out of the car, balance it and re-install it.
Any comments on that idea?:wall:

[Burntboot]

PG - I know nothing of Previa's but do understand how the dealer environment works.

Dealer techs spend a great deal of time in new car training and most customers only go to the dealer while their vehicle is in warranty.
Techs at dealers also tend to move around a fair bit, long gone are the days of getting a job and staying there for 20-25yrs.
As a result of the above 2 situations, finding a dealer that is actually conversant in 20+yr old vehicles is rare, not impossible but very rare.

If it were me, at this point I would pick up the yellow pages and look for a "driveline shop" someone who specializes in driveline problems.
If you can't find any in your area, go get friendly with the local transmission shop, they will have someone they can refer you to.
If all else fails, go to a high performance hot rod type of shop (or the guys that play with monster style trucks), they will definitely be able to refer you to someone who can help.

Good luck on your hunt.
BB

PS - the dealer doesn't have the required tooling to balance the shaft, all they are going to do is send it out, (likely to the same place your going to find by asking around)
but they will charge you a heavy mark-up for the privilege of doing so.

[timsrv]

What a nightmare. I would have explained the process better, but figured the drive-line shop would take care of you (after all it is a drive-line & that's their specialty). Regardless of what couplers you use, they should be installed 1st, then the shaft balanced as an assembly, then installed in the Previa. I haven't had one of these balanced by a drive-line shop yet, but am surprised they couldn't come up with a way to hold it in their machine. I'm guessing they don't see these very much and didn't want to make the effort for a single shaft. There's always the crude way I posted earlier in this thread, but IMO that should be a last resort. Sounds like you'll need to make some calls to find out who is capable. Frankly I'd be surprised if the dealer could do it. This is a specialty area & I'm guessing the'll send it out to have done. Perhaps you could call and find out where they send these..............and yes, the shaft will need to be removed again for balancing. Tim

[previagal]

PG - I know nothing of Previa's but do understand how the dealer environment works.

Dealer techs spend a great deal of time in new car training and most customers only go to the dealer while their vehicle is in warranty.
Techs at dealers also tend to move around a fair bit, long gone are the days of getting a job and staying there for 20-25yrs.
As a result of the above 2 situations, finding a dealer that is actually conversant in 20+yr old vehicles is rare, not impossible but very rare.

If it were me, at this point I would pick up the yellow pages and look for a "driveline shop" someone who specializes in driveline problems.
If you can't find any in your area, go get friendly with the local transmission shop, they will have someone they can refer you to.
If all else fails, go to a high performance hot rod type of shop (or the guys that play with monster style trucks), they will definitely be able to refer you to someone who can help.

Good luck on your hunt.
BB

PS - the dealer doesn't have the required tooling to balance the shaft, all they are going to do is send it out, (likely to the same place your going to find by asking around)
but they will charge you a heavy mark-up for the privilege of doing so.

Thank you, I'll try the monster truck route. I did however, already call around. The biggest driveline shop I spoke with the owner who was very familiar with this issue. He said he "might" be able to call his connection for balancing and would call me back. This is the guy all of the other shops (including the bozo shop who just charged me $550) would send their shafts to to be balanced back in the day. When he called me back he said the people he would have referred me to, no longer accept that job, and gave me three options. Stick with the bozo shop, buy a new shaft at dealer pricing and have it installed, or sell the car. None of those sound esp attractive to me, since I've got so much $$ invested now in all the other work, and I'm not going to waste any more time with the shop who gave the car back saying "we did you a big favor" and "it runs very smooth now" then overcharged me and the car was vibrating WAY worse after they were done, so that eliminates that option. That leaves new shaft or sell car.

Update: I just called two hot rod shops and the two bigger driveline shops they suggested. Hot rod shops said they don't have the skilled people to even attempt an R&R of a driveshaft like that and referred me to the driveline shops. The problem is the same. The driveline shop people tell me they simply do not have the "feet" to attach my shaft to their machines for balancing. Timsrv suggested the hose clamp method, and I'm up for trying that, but so far I've asked three shops and no one wants to do it that way, and I have no way to do it myself.
So it seems like my only viable option is to bite the bullet and have the dealer install a brand new one, eat it for $2K, but never have to worry about it again in another 150K miles. Geez that sounds painful it's so much money, it's turning into a ten thousand dollar car with a resale value of $2500.

OR, I could just drive it the way it is (which irks me) and get used to being shaken all to he** every time I drive it. That doesn't seem good either, damage front bearing, couplers wear out a lot faster, risk of explosion and expulsion, escape from reality with substance abuse, find a tall building and jump off, who knows what.:cnfsd:

[previagal]

What a nightmare. I would have explained the process better, but figured the drive-line shop would take care of you (after all it is a drive-line & that's their specialty). Regardless of what couplers you use, they should be installed 1st, then the shaft balanced as an assembly, then installed in the Previa. I haven't had one of these balanced by a drive-line shop yet, but am surprised they couldn't come up with a way to hold it in their machine. I'm guessing they don't see these very much and didn't want to make the effort for a single shaft. There's always the crude way I posted earlier in this thread, but IMO that should be a last resort. Sounds like you'll need to make some calls to find out who is capable. Frankly I'd be surprised if the dealer could do it. This is a specialty area & I'm guessing the'll send it out to have done. Perhaps you could call and find out where they send these..............and yes, the shaft will need to be removed again for balancing. Tim

It isn't a nightmare, it's an awake mare. LOL I've been waking up at 3:30 in the morning obsessing about and worrying about this job. And what burnboot said about the dealer makes a lot of sense.

What always really irks me is that people are in business, and yet have no standards for their own work. This driveline shop (and the brake shop before them - new rotors that they charged me $95 to machine before install- are wobbling- I noticed it, drive line shop pointed it out, head gasket shop pointed it out) obviously neither business cares about doing a good job, or doing it right, just get as much money out of the suckers as they can and who cares if the customer gets what they pay for. It turned out also, when I went back this morning to the shop that did the head gasket and brought up the important points I've learned myself in the past week, that the mechanic has been unbolting and re-bolting this shaft incorrectly every time he did it, all "20 of them" that he told me he installed. He didn't know you were supposed to mark it so you can return it to the same clock position (neither did I at the time or I would have given him a zerox of the factory service manual--which I have), and he didn't know that you were not supposed to let the shaft hang for any length of time. He tried some different clock position this morning, but it really didn't help. It still feels like I'm driving on a dirt road, and a rutted dirt road when I run the AC.

Here is my latest plan: recall the link I sent of the drive line shop in Colorado, that sells a new shaft that is "perfectly balanced" with "OEM type parts" etc?
http://www.coloradodriveshaft.com/toyota_previa.htm

Well they have the equipment to balance these shafts obviously. This afternoon, I emailed them and asked if they would build me a custom shaft with the OE couplers for $232 shipped found at Camelback Toyota, and explained my whole violin-playing, whiner sequence of events.

If they will build me a custom shaft (their "OE type" shafts are $300 plus exchange + shipping), I'm going to ask my mechanic who did the head gasket if he will install it, per the Service Manual procedure. If he does head gaskets, I'm sure he can handle this. I'd think it's the least he could do, since he was kind of the one who messed it up in the first place. If he won't, then I'll try to find a shop who will. These shops are funny, they don't really listen when I try to explain what's going on, I guess they don't think a woman knows what she's talking about, and they just go forwared diagnosing starting from ground zero, stumbling through all the "it could be this" "it could be that" processes, and they have to get their own parts. And if you don't agree to that, or try to steer them to what it actually is, because I know without a shadow of a doubt now its the shaft that's out of balance, they won't take your job.

I'll keep posting, because I'm sure others have encountered this problem, and the older these cars become, I think it's going to be more and more difficult to find a solution.Everyone who talks about doing this job, says nothing about the balancing, they just give instructions for replacing the couplers, taking the shaft out and putting it back etc, how it's not a hard job etc etc. I'm hoping to find SOME solution I can publish, so others who come in here unknowing, like I did, don't go through this awake mare. :dizzy:

[TheMAN]

the SADS TSB does not say anything about rebalancing the shaft, due to proper R&R procedures... mark the couplers at the right places before disassembly
so best thing as I have said from the beginning is to get a used 94-97 SADS and rebuild it with new couplers properly... if you even have basic tools, you can do it yourself before bringing the van to the shop to have them put it in

frankly, everything about this had gone wrong because you were anxiously trying to rush through fixing it and I am under the impression that you are not thinking through this with a cool head... to be honest, I made the mistake of rushing through things too in the past and it ended up costing me money, so believe me when I tell you I completely understand what you're going through... but, a crapped up SADS isn't going to snap in two and cause you to be on the side of the road... I've seen far worse beat to **** Previas and they're still running, after a very very long time from abuse

the solution it seems is clear and simple to me...
get a used 94-97 SADS, and get a new coupling kit from Toyota and get that put in... when I replaced my SADS with a brand new one, it had matching marks on it that went with the crankshaft pulley... I think the shop manual actually did say something about that too... it's not a big concern because I followed the instructions in the shop manual and put it in properly and it's been working great since

if any junk yard starts to give you a run around, tell them the van got hit and you're in the process of rebuliding it... anything to just BS your way through their crap... as I said... tell them what they want to hear, not what you want them to hear
how you present to a repair shop, or parts supplier makes a big difference... I hate to be presumptuous because we don't know you and have no idea what you say or how you present yourself of course, but if you sound or appear anxious, without confidence, people *are* going to take advantage of you... the fact you are loosing sleep over this tells me you just need to relax, to put it mildly... there's always solutions to a problem, and keeping cool in the face of problems goes a long way

[previagal]

the SADS TSB does not say anything about rebalancing the shaft, due to proper R&R procedures... mark the couplers at the right places before disassembly
so best thing as I have said from the beginning is to get a used 94-97 SADS and rebuild it with new couplers properly... if you even have basic tools, you can do it yourself before bringing the van to the shop to have them put it in

frankly, everything about this had gone wrong because you were anxiously trying to rush through fixing it and I am under the impression that you are not thinking through this with a cool head... to be honest, I made the mistake of rushing through things too in the past and it ended up costing me money, so believe me when I tell you I completely understand what you're going through... but, a crapped up SADS isn't going to snap in two and cause you to be on the side of the road... I've seen far worse beat to **** Previas and they're still running, after a very very long time from abuse

the solution it seems is clear and simple to me...
get a used 94-97 SADS, and get a new coupling kit from Toyota and get that put in... when I replaced my SADS with a brand new one, it had matching marks on it that went with the crankshaft pulley... I think the shop manual actually did say something about that too... it's not a big concern because I followed the instructions in the shop manual and put it in properly and it's been working great since

if any junk yard starts to give you a run around, tell them the van got hit and you're in the process of rebuliding it... anything to just BS your way through their crap... as I said... tell them what they want to hear, not what you want them to hear
how you present to a repair shop, or parts supplier makes a big difference... I hate to be presumptuous because we don't know you and have no idea what you say or how you present yourself of course, but if you sound or appear anxious, without confidence, people *are* going to take advantage of you... the fact you are loosing sleep over this tells me you just need to relax, to put it mildly... there's always solutions to a problem, and keeping cool in the face of problems goes a long way

I read the SADS TSB and it is more about how to install the couplers, than to do the entire R&R. I have the factory service manual, and it has the entire procedure for the R&R which is not in the TSB, so I'm very familiar with both.

Y'know, you have been sarcastic and rude from the get go first calling me paranoid, then telling me "who cares" when I posted something I though others might find useful. Now you're analyzing my personality flaws? I don't go to these shops acting unsure. I gave the stupid driveline shop the Xerox copy of the exact procedure for removing and installing the shaft, from my own copy of the Factory Service Manual, the big yellow book that is 3" thick, and explained what happened when the head gasket was done. I also gave them the TSB for the coupler installation instructions, and basically they laughed in my face and told me "we've been doing this a long time (in a tone that was patronizing and intolerant.) I don't have any control over people who think they know it all and aren't open to listening, no matter how I approach them. Just like you. You're not really reading what I'm writing and your comments prove it. for example, I never said the wrecking yards were giving me trouble. I found two who will sell me a shaft no problem. The mechanic who did the head gasket is a really good mechanic, he just didnt' know the few critical steps when disconnecting the shaft from the motor. The driveline shop did a crappy job because they have no work ethic, and other shops do not want to install customer supplied parts due to liability and warranty issues. They just don't go there, and I know this because I've asked.
FYI, I wasn't "rushing" through anything. I was taking the advice of people in the forum and there is a learning curve to everything. I bought the Factory Service Manual off of ebay on Monday,and got it on Wed, so everything was a lot more clear when I actually saw the whole thing laid out. Honestly, I don't need a new shaft and couplers, I need to find a shop who has the tooling to balance the one I have.
Especially if I buy a shaft from a wrecking yard there is NO WAY to know where to line a wrecking yard shaft up, so it's logical to assume that the same balancing problem comes up. And you're telling me to get a wrecking yard shaft when that isn't what you did? You said you installed "a brand new one" in your car?
I'm well aware I'm not going to break down or get stranded from a vibration in the SAD, I just don't enjoy driving a car that feels like I'm driving a tractor, especially after I just spent over $3K on new front brakes, new head gasket, new SAD couplers, having this big vibration is ANNOYING. And it bugs me because when you pay people hundreds/thousands of dollars to do a job and it comes out bad, it BUGS ME. I'm trying to keep my van in nice condition, becauise I've learned the hard way that if you let things go thinking you'll fix whatever it is later, at some point it feels like the whole car is falling apart. I'm hoping to get another 100K miles at least out of this car, since it only has 167K miles, and a newer car is not affordable. At least fixing things when they need repair, I know what I've got and can trust it. While I'm not anxious, I'll admit I am a *little* OCD about my cars, because I don't want to worry about car problems. I want to take care of all this stuff so I can just go out and drive it and not have things malfunctioning out camping somewhere or crossing the desert/valley etc hundreds of miles from civilization. I take mountain bike trips, I'm out in the dern wilderness by myself a lot. The last thing I want to worry about is car problems. And I love my van, it's perfect for camping and hauling bikes around.:)

[TheMAN]

Excuse me for "sounding" rude when I stated "who cares" simply meant "who cares, what part number it is when whatever it is, worked", and not "who cares what you thought it was"
Excuse me for not being more sensitive during the time of your distraught emotional state

Please accept my sincere apologies for concluding that your emotional state took everything out of context

Best of luck getting your van fixed!

[previagal]

Excuse me for "sounding" rude when I stated "who cares" simply meant "who cares, what part number it is when whatever it is, worked", and not "who cares what you thought it was"
Excuse me for not being more sensitive during the time of your distraught emotional state

Please accept my sincere apologies for concluding that your emotional state took everything out of context

Best of luck getting your van fixed!

I know exactly what you meant by "who cares." And now you're talking about my distraught emotional state? :wnk: I have to ask though, you said there's always a solution, my available solutions, are: 1) buy a new shaft from the dealer and get the shaft for over $2K for the part and install, 2) live with the vibration, or3) find a shop who can balance the shaft and do the R&R. You can do your own work, have you checked lately to find, most shops wont' touch this job with a ten foot pole. Which limits the options I have, compared to yours. Where do you live, will you fix my car? (laughing here) LOL~!

1896

[pdgizwiz]

For what it's worth, I'm a man, have worked on cars for many decades, and understand machinery at a level that few professional auto mechanics could ever comprehend. Guess what! They treat me the same way. Whenever I take a car to a shop (for want of the time, specialized tooling, etc.) to have work done, I'm ignored, talked down to, and in the end, nearly always disappointed and disgusted. They have a pattern of operation that works overall on an ignorant and gullible marketplace, and I'm way too much trouble for them to cope with.

On the subject of SADS, I'm not convinced that balancing after a coupling replacement is essential to a successful repair. Marking the components for re-assembly certainly is, but the components align themselves independent of the couplings, which carry the torque only.

If imbalance is introduced as a result of the replacement of the couplings, it's due to the change in the couplings themselves. One reason that I don't trust the urethane couplings is that I don't trust them to have a center of gravity that lands on the shaft axis. In my judgement -take it for what it's worth- the machined aluminum units are more likely to be uniform in the distribution of their mass.

Finding a shop that can dynamically balance your SADS may be a challenge. Finding one that will charge you to try might be easier, but I wouldn't want to go there. Given the landscape I described in the first paragraph of this post, I decided to take my chances ignoring the issue. Sample of one: I replaced the couplings on my '93 and it runs more smoothly than an OEM shaft I put in another van.

[previagal]

For what it's worth, I'm a man, have worked on cars for many decades, and understand machinery at a level that few professional auto mechanics could ever comprehend. Guess what! They treat me the same way. Whenever I take a car to a shop (for want of the time, specialized tooling, etc.) to have work done, I'm ignored, talked down to, and in the end, nearly always disappointed and disgusted. They have a pattern of operation that works overall on an ignorant and gullible marketplace, and I'm way too much trouble for them to cope with.

On the subject of SADS, I'm not convinced that balancing after a coupling replacement is essential to a successful repair. Marking the components for re-assembly certainly is, but the components align themselves independent of the couplings, which carry the torque only.

If imbalance is introduced as a result of the replacement of the couplings, it's due to the change in the couplings themselves. One reason that I don't trust the urethane couplings is that I don't trust them to have a center of gravity that lands on the shaft axis. In my judgement -take it for what it's worth- the machined aluminum units are more likely to be uniform in the distribution of their mass.

Finding a shop that can dynamically balance your SADS may be a challenge. Finding one that will charge you to try might be easier, but I wouldn't want to go there. Given the landscape I described in the first paragraph of this post, I decided to take my chances ignoring the issue. Sample of one: I replaced the couplings on my '93 and it runs more smoothly than an OEM shaft I put in another van.

Thank you. Ultimately, I ended up using the aluminum couplers as a last minute correction and sent the urethane ones back for a refund. OK, so I am trying to relate your explanation to my situation because it sounds logical, but the shaft/couplers are so messed up now, I'm not sure it applies. Here is the sequence of events (let me know what you think if you have time):

1) had head gasket done. Mechanic did not mark the shaft, and did not support the shaft when it was unbolted, while the engine was out.
2) got the car back and had vibration in the front end
3) took to driveline shop, assuming head gasket mechanic was not experienced to correct what he messed up.
4) driveline shop rejected the input I gave them did not look at re-install instructions I provided from factory service manual (who knows if they removed it properly either?) and installed new couplers. Original complaint was vibration. I also provided the toyota service bulletin for their review, which lists each step for replacing the couplers.
5) Vibration is much worse after driveline shop work. I do not want to go back there because the owner basically blew me off with a rude denial of responsibility when I brought the car back stating it was much worse than before, so I wrote them a letter asking for a refund of $200 from their labor charge which was $342 for 3.6 hours to R&R the shaft and replace the couplers. Have not heard back yet.
6) Took it back to head gasket mechanic, explained at that time (which he was not previously aware of) that the shaft had to be marked so it could be replaced in the same clock position. That mechanic put the car up on the lift and showed me the shaft etc, and tried the other two clock positions (there are only three is what it looked like).
7) Now this is the weird part. Position #1 will be referred to as the existing position when I brought it there. He moved it to the second position, and we test drove together. Vibration seemed "better". Then he said he was going to try clock position #3 to see if the vibration would be eliminated altogether.He did that, drove it by himself and said it was worse, and that he was going to put it back to position #2. Put back to position #2, and when I drove it away, it was as bad as it ever was, worse than our test drive together when it was in position #2.
8) Dealer said they charge $115 to diagnose, but another poster made the point that the dealer mechanics are well trained in the newer cars but a dealer technician with experience with this problem is unlikely, so whoever gets it isn't really going to know beans about what's going on and I'm thinking they're just going to tell me I need a new shaft. I thought I could talk to the shop foreman and hopehe doesn't have a vacant stare when I explain it all.
9)I have been assuming the problem is due to imbalance, but now your're saying it is due to the coupler change. If this is true, then is it possible that the know-it-alls at the driveline shop did not install them properly? That means it isn't a balance issue? I guess anything is possible, but how hard can it be, to take the old ones out and put the new ones in? Does it require extensive experience with a multitude of tricky variables? These are only hypothetical questions because I haven't done it myself.
9) If it isn't a balance issue why would revolving the shaft to a different clock position, improve the vibration slightly?
10) This could drive someone crazy, geez, it doesn't seem like it should be this complicated.:wall:

[pdgizwiz]

Sorry if I only confound the issue here...

When I mentioned that I believe it important to "mark the components" I was referring to the SADS itself, which has three main components joined by the two couplers. I was not referring to the junction between the SADS and the big harmonic balance pulley on the front of the engine. Where there are three possible positions by which the SADS can be attached to the engine, there are nine different ways that the three componets of the SADS can be assembled.
That said, I can't fathom how changing how the SADS is positioned with respect to the engine would dramatically affect balance. After all, people swap from one SADS to another commonly without issue. Same with engines, axles, driveshafts, and other such sub-assemblies. Driveshafts (including SADS) are balanced as assembled units at the factory. But I doubt that a SADS is balanced at the factory with respect to a particular engine, in a particular position. If so, there is virtually no chance of a "do-over".

I know that it is common "best practice" to mark flanges when removing such sub-assemblies. But this is meaningless when you replace one of those components.

From the sequence you described, I gather that your SADS was not disassembled when your head gasket job was done. If you went in with a bad head gasket and came out with a vibration, I can only speculate that something wasn't assembled carefully. I know that's of no help to you, and I'm sorry.

The Previa is a peculiar beast. That happens to be one reason they appeal to me, but only because I have committed to doing my own work. The comment about a typical dealer's ability to diagnose their peculiar problems is valid. My experience with my local Toyota dealer is that I can't get past the service manager to speak with the individual mechanics. There may well be a Previa expert back there, but they keep him/her busy working on the newer cars that demand their special expertise as well (and belong to recent new-car purchasers). I've been happy with my local dealer, but I only use them for well-defined tasks on my wife's Avalon that I don't want to fuss with myself.

Independent shops vary wildly in quality. Many are well run and reasonably competent, and many are crooks. A few specialize in particular cars. If there were an abundance of Previa specialty shops competing for business, there would be some good ones. VW shops were abundant when there were bazillions of VWs buzzing around. But that isn't the case for Previas, and won't be, ever, because there just aren't that many Previas being saved from the crusher. Your experience speaks to why that is the case.

People often ask me how to choose a good used car. I tell them to first figure out where they're going to have it worked on.

[previagal]

Sorry if I only confound the issue here...

When I mentioned that I believe it important to "mark the components" I was referring to the SADS itself, which has three main components joined by the two couplers. I was not referring to the junction between the SADS and the big harmonic balance pulley on the front of the engine. Where there are three possible positions by which the SADS can be attached to the engine, there are nine different ways that the three componets of the SADS can be assembled.
That said, I can't fathom how changing how the SADS is positioned with respect to the engine would dramatically affect balance. After all, people swap from one SADS to another commonly without issue. Same with engines, axles, driveshafts, and other such sub-assemblies. Driveshafts (including SADS) are balanced as assembled units at the factory. But I doubt that a SADS is balanced at the factory with respect to a particular engine, in a particular position. If so, there is virtually no chance of a "do-over".

I know that it is common "best practice" to mark flanges when removing such sub-assemblies. But this is meaningless when you replace one of those components.

From the sequence you described, I gather that your SADS was not disassembled when your head gasket job was done. If you went in with a bad head gasket and came out with a vibration, I can only speculate that something wasn't assembled carefully. I know that's of no help to you, and I'm sorry.

The Previa is a peculiar beast. That happens to be one reason they appeal to me, but only because I have committed to doing my own work. The comment about a typical dealer's ability to diagnose their peculiar problems is valid. My experience with my local Toyota dealer is that I can't get past the service manager to speak with the individual mechanics. There may well be a Previa expert back there, but they keep him/her busy working on the newer cars that demand their special expertise as well (and belong to recent new-car purchasers). I've been happy with my local dealer, but I only use them for well-defined tasks on my wife's Avalon that I don't want to fuss with myself.

Independent shops vary wildly in quality. Many are well run and reasonably competent, and many are crooks. A few specialize in particular cars. If there were an abundance of Previa specialty shops competing for business, there would be some good ones. VW shops were abundant when there were bazillions of VWs buzzing around. But that isn't the case for Previas, and won't be, ever, because there just aren't that many Previas being saved from the crusher. Your experience speaks to why that is the case.

People often ask me how to choose a good used car. I tell them to first figure out where they're going to have it worked on.

Thank you, actually what you're saying is VERY helpful and makes a lot of sense after I studied the Coupler service bulletin and the repair manual more last night.

The TSB for coupler replacement does show that the front and rear coupling flanges should be marked before removing the couplers for replacement. I'll need to ask my mechanic to put the car up on the lift and see if there are any marks.

Then the service manual says if the drive line stays are to be removed, they need to be marked because these stays greatly influence the angle of the driveshaft and they should be marked so as to be returned to their original position. I will need to ask the mechanic if he removed these stays. There is no way to find out if the driveline shop removed them, but my guess is they did, because the vibration after they replaced the couplers was much worse, than after I got the car back from the head gasket work. Then it says that the angle of the driveshaft should be measured in front of and behind the front flexible coupling. If the difference in the angle between each section is 2 degrees or more, correct the installation angle by adjusting the position of the No. 1, No. 2, and or No. 3 drive housing stays. They talk about an "angle gauge SST 09370-50010. Which I have not been able to find online, because I'm pretty sure the shop that did the headgasket probably doesn't have it since they send drive shafts out. If your theory is correct, I now have no way of knowing where the correct alignment is supposed to be with the individual parts in the 3-part assembly, and would have to start over with a new shaft, correct?If I buy a wrecking yard shaft, I'm taking my chances again that is was assembled wrong aren't I?

Because for all I know, mine is completely misaligned now (the 9 possible positions) and how would they even know where to put it back together since they obviously didn't mark it?:cnfsd:

Aside from that question mark, Timsrv, the admin on this site, mentioned the requirement for balancing the shaft after removal and install of new couplers, before putting it back in the car. He also has a lot of experience.......so I think it can go out of balance for whatever reason.
If I could find one person willing to, aware of the requirements and who has been successful in doing this work in the correct manner, even someone on this forum, I would willingly pay whatever the going book rate is for the labor, or more. The driveline shop charged me $95 per hour.

[previagal]

Sorry if I only confound the issue here...

When I mentioned that I believe it important to "mark the components" I was referring to the SADS itself, which has three main components joined by the two couplers. I was not referring to the junction between the SADS and the big harmonic balance pulley on the front of the engine. Where there are three possible positions by which the SADS can be attached to the engine, there are nine different ways that the three componets of the SADS can be assembled.
That said, I can't fathom how changing how the SADS is positioned with respect to the engine would dramatically affect balance. After all, people swap from one SADS to another commonly without issue. Same with engines, axles, driveshafts, and other such sub-assemblies. Driveshafts (including SADS) are balanced as assembled units at the factory. But I doubt that a SADS is balanced at the factory with respect to a particular engine, in a particular position. If so, there is virtually no chance of a "do-over".

I know that it is common "best practice" to mark flanges when removing such sub-assemblies. But this is meaningless when you replace one of those components.

From the sequence you described, I gather that your SADS was not disassembled when your head gasket job was done. If you went in with a bad head gasket and came out with a vibration, I can only speculate that something wasn't assembled carefully. I know that's of no help to you, and I'm sorry.

The Previa is a peculiar beast. That happens to be one reason they appeal to me, but only because I have committed to doing my own work. The comment about a typical dealer's ability to diagnose their peculiar problems is valid. My experience with my local Toyota dealer is that I can't get past the service manager to speak with the individual mechanics. There may well be a Previa expert back there, but they keep him/her busy working on the newer cars that demand their special expertise as well (and belong to recent new-car purchasers). I've been happy with my local dealer, but I only use them for well-defined tasks on my wife's Avalon that I don't want to fuss with myself.

Independent shops vary wildly in quality. Many are well run and reasonably competent, and many are crooks. A few specialize in particular cars. If there were an abundance of Previa specialty shops competing for business, there would be some good ones. VW shops were abundant when there were bazillions of VWs buzzing around. But that isn't the case for Previas, and won't be, ever, because there just aren't that many Previas being saved from the crusher. Your experience speaks to why that is the case.

People often ask me how to choose a good used car. I tell them to first figure out where they're going to have it worked on.

One more point. In the factory repair manual, the requirement to mark the shaft with respect to the rear coupling, flange and crankshaft pulley is in the book in three separate sections. Once in the beginning pages of the manual under "Introduction: Precautions" again in the head removal section, and again in a section dedicated specifically to the SAD. If marking it with respect to where it went in relation to the engine pulley was not important, why would they have it in three sections of the book? Because if I'm understanding you correctly, the sections you're saying need marking are part of the shaft assembly, and don't include the pulley etc. not for balance anyway. What would be a reason for marking the pulley? In other words ,what would not connecting it back at the same clock position in relation to the affect?

[previagal]

One thing I just read in the factory repair manual is they state: "the flexible coupling is not to be disassembled. Do not re-use a flexible coupling which has been disassembled." And suggest replacing the assembly as a unit. Then on another page, it talks about "fluid coupling" and says check for no leaks and no silicone oil leakage. What Previa did that come on, because the couplers they replaced on my car had no fluid or liquid at all, they were aluminum, with rubber bushings with a metal insert. Is this something that went on the model with the supercharger?
I got the manual for the 1994, but I guess since my production date is 8/93 and it takes the smaller bolt diameter of the 91-93 coupler, I should have gotten the '93 manual, since in early 94 models the supercharger was an option, but on anything newer it came stock on all vehicles produced after whatever date in 1994, is my understanding.

[timsrv]

I'm not sure why the FSM threw it in where they did, but the "fluid coupling" they refer to is the clutch for the radiator fan (all years of Previa have this & it's not part of the shaft). I'm torn on the necessity of marking the front crankshaft pulley, because it's unlikely this is balanced to the shaft............but since marking doesn't hurt, I say mark away (when in doubt, mark it). I already mark and double check things way more than required (because I don't like problems & don't like taking unnecessary chances).

pdgizwiz, I agree it makes sense that the front pulley (harmonic balancer) wouldn't be balanced to the shaft, but previagal is right about the manual saying to mark it with the shaft and align the same when putting back. Still, from the standpoint of replacing the entire shaft, since new shafts don't include new front pulleys as part of "the balanced assembly", it's a conflict (on Toyota's part), so I'd have to side with you on this (it shouldn't matter).

When it comes to any balanced rotating assembly it's always best to finish any maintenance with a spin balance (just because). But for most shafts, you have to wonder just how important it really is. In the aircraft industry we balanced (or had balanced) everything............so we never really thought about it (just do it!). Of course these vans aren't aircraft, so it becomes more of a comfort/longevity issue. In cases like this where balancing is reportedly a very daunting and/or difficult task, it just makes sense to mark everything and keep things as close to original positions as possible.

I replaced the flex couplers on my 91 Previa with the urethane ones without balancing. I gave it some thought, but balancing would have been a PITA, so I decided to give it a try & go back, remove & balance if required. Turns out I must have been lucky because everything was smooth (but I did mark and put things back exactly as before). Of course something is vibrating now (16k miles later) & it's likely that shaft, but I'm thinking it's the couplers falling apart. On a shaft where a vibration has already been an issue (like previagal's), a final spin balance now becomes a necessity (or a whole other shaft assy will need to be procured).

There's always the chance that the shaft is vibrating due to taking a hit and/or becoming "out of round". I would inspect it to see if there's any impact marks on it. I would also check to see if there's evidence of weights being removed or knocked off. If your shaft has excessive balancing weights welded to it, then it stands to reason positions of the 3 main parts are more critical on this particular shaft (you have to wonder why so much counter balance was required........was it due to the main body of the shaft being off, or one of the end parts being off).

Based on mass, I'm of the opinion that the flexible couplers and the engine side of the shaft assembly won't make nearly as much difference (in regard to balancing) as the shaft itself or the front part of the assembly. So, if there's a balance issue, these are the parts I'd suspect (or possibly a steel bushing or 2 that isn't seated properly in it's bore). One more thing that's troubling to think about...........what if they installed the wrong flexible couplers? If your shaft was actually the later model & if earlier couplers (with too small of steel bushings) were used, the attach points wouldn't positively align and the shaft could be "out of round". If the shaft is indeed the earlier one (91 - 93) & the couplers for the newer shaft were used, the steel bushings would be too big would & not go into their bores. This would create the same issue, but with the added stress on the rubber due to the shaft now being a bit too long. IMO that's not likely though as it's hard to conceive of a drive line shop being that incompetent :dizzy:. Tim

[previagal]

I'm not sure why the FSM threw it in where they did, but the "fluid coupling" they refer to is the clutch for the radiator fan (all years of Previa have this & it's not part of the shaft). I'm torn on the necessity of marking the front crankshaft pulley, because it's unlikely this is balanced to the shaft............but since marking doesn't hurt, I say mark away (when in doubt, mark it). I already mark and double check things way more than required (because I don't like problems & don't like taking unnecessary chances).

pdgizwiz, I agree it makes sense that the front pulley (harmonic balancer) wouldn't be balanced to the shaft, but previagal is right about the manual saying to mark it with the shaft and align the same when putting back. Still, from the standpoint of replacing the entire shaft, since new shafts don't include new front pulleys as part of "the balanced assembly", it's a conflict (on Toyota's part), so I'd have to side with you on this (it shouldn't matter).

When it comes to any balanced rotating assembly it's always best to finish any maintenance with a spin balance (just because). But for most shafts, you have to wonder just how important it really is. In the aircraft industry we balanced (or had balanced) everything............so we never really thought about it (just do it!). Of course these vans aren't aircraft, so it becomes more of a comfort/longevity issue. In cases like this where balancing is reportedly a very daunting and/or difficult task, it just makes sense to mark everything and keep things as close to original positions as possible.

I replaced the flex couplers on my 91 Previa with the urethane ones without balancing. I gave it some thought, but balancing would have been a PITA, so I decided to give it a try & go back, remove & balance if required. Turns out I must have been lucky because everything was smooth (but I did mark and put things back exactly as before). Of course something is vibrating now (16k miles later) & it's likely that shaft, but I'm thinking it's the couplers falling apart. On a shaft where a vibration has already been an issue (like previagal's), a final spin balance now becomes a necessity (or a whole other shaft assy will need to be procured).

There's always the chance that the shaft is vibrating due to taking a hit and/or becoming "out of round". I would inspect it to see if there's any impact marks on it. I would also check to see if there's evidence of weights being removed or knocked off. If your shaft has excessive balancing weights welded to it, then it stands to reason positions of the 3 main parts are more critical on this particular shaft (you have to wonder why so much counter balance was required........was it due to the main body of the shaft being off, or one of the end parts being off).

Based on mass, I'm of the opinion that the flexible couplers and the engine side of the shaft assembly won't make nearly as much difference (in regard to balancing) as the shaft itself or the front part of the assembly. So, if there's a balance issue, these are the parts I'd suspect (or possibly a steel bushing or 2 that isn't seated properly in it's bore). One more thing that's troubling to think about...........what if they installed the wrong flexible couplers? If your shaft was actually the later model & if earlier couplers (with too small of steel bushings) were used, the attach points wouldn't positively align and the shaft could be "out of round". If the shaft is indeed the earlier one (91 - 93) & the couplers for the newer shaft were used, the steel bushings would be too big would & not go into their bores. This would create the same issue, but with the added stress on the rubber due to the shaft now being a bit too long. IMO that's not likely though as it's hard to conceive of a drive line shop being that incompetent :dizzy:. Tim

Thank you,
Just to address a couple things, the driveline shop was clear on the size of the couplers. The urethane ones had numbers like 524 and 525. 524 is the smaller one, and that's what they sent. I had the distributor for the urethane couplers call the driveline shop to confirm the size, and the driveline shop told me I had the smaller size. So I'm pretty sure they got the right aluminum ones. Also, your experience that the problem is more on the non-engine side is supported by my latest conclusions after speaking this morning to the shop foreman at the Dealer and then to Colorado Driveline, who produces a perfectly balanced shaft with OE type couplers for $300 plus core exchange. Here is what I've learned:

Colorado Drive shaft confirmed that every shaft should be rebalanced if removed from the car. This may be the Achilles heel of using urethane couplers, because it seems like urethane would get pounded out of shape a lot faster than aluminum if the shaft is not perfectly balanced and how long they last is probably relative to how much out of balance the shaft might be. The less out of balance, the longer the urethane lasts. Since no one has the equipment to balance the shaft, urethane probably has a bad rap and might be a viable solution if the shaft could be balanced. But that's a moot point, since most people not having sources to balance the shaft, then makes it not an acceptable part, just my unqualified opinion. I"m so glad I ended up not using those, although what I finally decided to do is going to eliminate coupler type choice or incorrect installation this time around.

So moving right along, the driveline shop did not balance the shaft (admitted they don't have the tooling to do it) in addition to maybe not replacing the couplers the way they were supposed to (marking each of the three sections) or maybe not doing the R&R of the whole assembly correctly when they took it out and put it back in the car, which has specific requirements, it isn't like a standard drive shaft. In speaking with the Dealer shop foreman this morning, and also confirmed by Colorado Driveshaft, it's unlikely the vibration is due to being "that much" out of balance unless the drive shaft was bent. I would think when the driveline shop took it out of the car, they could have seen if it was bent, or is this a false assumption and if it was bent they wouldn't notice? After speaking with Colorado Driveshaft and the Dealer shop foreman this morning, here are my latest conclusions, and what my final decision is on how to fix the problem:

Most likely, the couplers were damaged on the non-engine side of the shaft, when the mechanic let the drive shaft hang unsupported for days when the head gasket was being done, which caused the initial vibration. Then it got worse when the driveline shop did not R&R the couplers correctly, or did not R&R the shaft assembly in and out of the car correctly. The mechanic at the head gasket shop keeps arguing with me when I point out that the shaft needed to be supported, saying that "the shaft is heavy duty and the factory repair manual is overkill, and the shaft does not need to be supported" which Colorado Drive line and the dealer both contradict, saying the rubber bushings can become distorted and crack if the shaft is not supported for any length of time ("length of time" is the critical element here) which is the case when left hanging for days during a head gasket job.
Also learned, something the driveline shop may have messed up on, the installation angle of the drive shaft in front and behind the front coupling cannot be more than 2 degrees.
Colorado Driveshaft uses refurbished OE shafts, and replaces with "OE type" couplers, and then balances the whole assembly. They offer this option with a one-year warranty for $300 (plus shipping in my case). In asking them about the "OE type" couplers, they confirmed they are not as good as the OE parts, but they would be willing to put an assembly together for me with the OE parts, if I furnish the OE couplers. I told them I can get them online from the Toyota dealer in Mesa, AZ for $232. So what I have decided to do is have them build the refurbished shaft and supply them with the OE couplers, have it shipped here, and then find a mechanic who is willing to follow the factory installation instructions, instead of arguing. Or, I will try to have my mechanic here who did the head gasket, speak with Colorado Driveshaft about letting the shaft hang, which he believes is ok, which Colorado Driveshaft said "oh no, he let the whole weight of the drive shaft hang?!"
So that's what I'm going to do. And then I don't have to deal with this again, for another 150K miles hopefully.

[timsrv]

Based on the available options I believe this to be your best course of action. The only potential "fly in the ointment" would be your mechanic and his cavalier attitude toward the SADS assembly (personally I wouldn't want somebody like that working on my equipment). I know there's no guarantee the dealer would do the job correctly, but have you asked to see if they would install? Installing a complete assembly on a RWD Previa isn't a big deal, but after all the hands that were on yours, I would want the alignment & mounts of your front accessory assembly checked. IMO the dealer is the one most likely to do the job correctly. Of course I'm sure they'll say "due to liability, we cannot install parts provided by anybody but us"........yadda yadda. What they really mean is "We don't want to mess with it unless we can also scalp you $1,500 for a shaft we pay $750 for".

[previagal]

Based on the available options I believe this to be your best course of action. The only potential "fly in the ointment" would be your mechanic and his cavalier attitude toward the SADS assembly (personally I wouldn't want somebody like that working on my equipment). I know there's no guarantee the dealer would do the job correctly, but have you asked to see if they would install? Installing a complete assembly on a RWD Previa isn't a big deal, but after all the hands that were on yours, I would want the alignment & mounts of your front accessory assembly checked. IMO the dealer is the one most likely to do the job correctly. Of course I'm sure they'll say "due to liability, we cannot install parts provided by anybody but us"........yadda yadda. What they really mean is "We don't want to mess with it unless we can also scalp you $1,500 for a shaft we pay $750 for".

Here is the latest after taking the car back this morning to the head gasket shop, because the overdrive light came on again, of course Friday at 6pm. LOL No car all weekend. I'm sure getting in good shape riding my bike in 90 degree heat through all the days of car problems! I also brought the factory manuals with me, to show the mechanic about letting the shaft hang, and also asked him to look at the coupler installation TSB (which Tim kindly furnished, thank you that was very helpful for me and the mechanic - too bad the driveline shop didn't look at it.)and look at the coupler/assembly of those parts to see if they were marked by the driveline shop. What he said was on the "triangles" which (I think) they're calling the flanges in the service manual, there were marks, but the one on the engine side did not line up with the ones on the balancer side, He said they were about "8 degrees" ( I guess like 20 minutes on a clock) offset to each other. This was absolutely the fault of the driveline shop, since they were the ones who took these particular components apart. Also, this morning when I left the car, I left the service bulletin and the factory manual, and showed him the pages where it says support the shaft etc. He argued this morning, but (I think) after reading what I had highlighted with yellow, which was the part about don't leave the shaft unsupported "for a long period", he admitted when I came back to pick the car up, that he had left it unsupported for five days, and now understands that was wrong. What I have found in making assertion messages like that one about supporting the shaft, is that people will always reject them at first and get defensive. So the key is to calmly keep repeating the message, and eventually, reasonable people will allow it to seep into their previously held ideas. And that is exactly what happened! Geez, I was so happy he admitted and understood the original problem :) So I told him my plan to provide the OE couplers to Colorado Driveshaft and he said he would absolutely "be very careful" when he installs the new shaft and install it completely to the factory spec. Tim, I hear you about alignment and mounts, I did point out this morning, that the shaft needs to have no more than a 2 degree angle between the front and back on each side of the front coupler. When I went to pick the car up, my mechanic said he didn't have the tool to do that measurement, because I asked him to check to see if the driveline shop by some chance messed that up. Anyway, the next task is for me to find that tool and buy it. (unless it's a thousand bucks which I can't imagine.) The factory manual refers to it as SST Angle Gauge 09370-50010. SST = Special Service Tool. This is also found in the 2007 Lexus Special Service Tool PDF on the 5th page in the sequence of pages on the PDF, but on Pg 3 in the document pagination at the bottom of each page. I highlighted it in yellow. I found a phone number on the web for a company called SPX/OTC, and when you call that number (800-933-8335) one of two options is for Toyota Special Service tools.
They didn't have pricing when I called so they're going to call me back. I'm hoping that the reason their computer shows no pricing is not because it's no longer available. :doh: If that's the case, I'm not sure about where to go on that one, since the dealer told me they don't have the balancing equipment, maybe they don't have this driveline angle tool either. Although I found it on Amazon as a generic tool, so maybe it's generic and not specific to the SAD. Fingers crossed.

1902

[timsrv]

Wow! Nice win with the mechanic :)>:. He must be an okay guy. Most of the techs I know would have gotten pissed off and told you not to come back :lol:. A guy that admits he was wrong..........how often does that happen? :roflmao:

It's been years since I've purchased SSTs (back before the internet) so I don't have a web site for you. But I got out my old school Rolodex and found the name and number of the place I used to order from. It's Kent-Moore tools at 800-345-2233. Don't have time right now to check it out & see if they're still in business, but you never know. Let us know what you find out. Depending on what the tool is & how much $$$ it costs, I might be interested in buying it from you after you're done with it (assuming you don't want it). Tim

[previagal]

Wow! Nice win with the mechanic :)>:. He must be an okay guy. Most of the techs I know would have gotten pissed off and told you not to come back :lol:. A guy that admits he was wrong..........how often does that happen? :roflmao:

It's been years since I've purchased SSTs (back before the internet) so I don't have a web site for you. But I got out my old school Rolodex and found the name and number of the place I used to order from. It's Kent-Moore tools at 800-345-2233. Don't have time right now to check it out & see if they're still in business, but you never know. Let us know what you find out. Depending on what the tool is & how much $$$ it costs, I might be interested in buying it from you after you're done with it (assuming you don't want it). Tim

Thank you! Yes, the mechanic who did the head gasket is a really good mechanic. He's smart, is willing to discuss (that's worth a gold watch right there :o) and has a lot of experience.Not to mention, dealing wtih "some woman with her own factory book" giving him information LOL ~! He is a good guy. Which is why I wanted to keep working with him to solve these problems instead of playing the blame game and making him mad(der). Hopefully, once I get this *new* *perfectly balanced* shaft with *OE couplers* from Colorado Driveshaft, and he does the install correctly, the SAD will last the remainder of the life of the vehicle, like another 150K miles and I won't ever have to deal with this again, or need that angle tool. That would be the best case scenario. I'll wait to hear back from SPX/OTC and if they don't have it, I'll try your guy and keep you posted.

[previagal]

Wow! Nice win with the mechanic :)>:. He must be an okay guy. Most of the techs I know would have gotten pissed off and told you not to come back :lol:. A guy that admits he was wrong..........how often does that happen? :roflmao:

It's been years since I've purchased SSTs (back before the internet) so I don't have a web site for you. But I got out my old school Rolodex and found the name and number of the place I used to order from. It's Kent-Moore tools at 800-345-2233. Don't have time right now to check it out & see if they're still in business, but you never know. Let us know what you find out. Depending on what the tool is & how much $$$ it costs, I might be interested in buying it from you after you're done with it (assuming you don't want it). Tim

UPDATE ON SPECIAL SERVICE TOOL SOURCE: I just called Kent-Moore, the person who answered the phone there told me Kent-Moore is "under the same umbrella" as SPX/OTC and gets their Special Service Tools from the same source as the SPX/OTC company I listed in my first reply.

[previagal]

Based on the available options I believe this to be your best course of action. The only potential "fly in the ointment" would be your mechanic and his cavalier attitude toward the SADS assembly (personally I wouldn't want somebody like that working on my equipment). I know there's no guarantee the dealer would do the job correctly, but have you asked to see if they would install? Installing a complete assembly on a RWD Previa isn't a big deal, but after all the hands that were on yours, I would want the alignment & mounts of your front accessory assembly checked. IMO the dealer is the one most likely to do the job correctly. Of course I'm sure they'll say "due to liability, we cannot install parts provided by anybody but us"........yadda yadda. What they really mean is "We don't want to mess with it unless we can also scalp you $1,500 for a shaft we pay $750 for".

Forgot to include in my prior two windbag replies, my mechanic this morning said it looked like the mounts were not removed, because the washers would have shown differently, so the driveshaft shop probably did not mess with the alignment. After looking at the factory manual a little more, it appears these stays (which I originally thought were part of the shaft assembly) are on an assembly called the Equipment drive housing, not on the shaft assembly itself. So if those stays were not removed (which my mechanic said they weren't), is it safe to assume that aspect was untampered with and would not need re-alignment (Especially since there was no vibration at all before the head gasket job)? If I don't have to buy that SST, that would be helpful. The manual says do not remove those stays when removing the shaft, so I don't see my mechanic removing those either to do the new install.

[previagal]

Sorry if I only confound the issue here...

When I mentioned that I believe it important to "mark the components" I was referring to the SADS itself, which has three main components joined by the two couplers. I was not referring to the junction between the SADS and the big harmonic balance pulley on the front of the engine. Where there are three possible positions by which the SADS can be attached to the engine, there are nine different ways that the three componets of the SADS can be assembled.
That said, I can't fathom how changing how the SADS is positioned with respect to the engine would dramatically affect balance. After all, people swap from one SADS to another commonly without issue. Same with engines, axles, driveshafts, and other such sub-assemblies. Driveshafts (including SADS) are balanced as assembled units at the factory. But I doubt that a SADS is balanced at the factory with respect to a particular engine, in a particular position. If so, there is virtually no chance of a "do-over".

I know that it is common "best practice" to mark flanges when removing such sub-assemblies. But this is meaningless when you replace one of those components.

From the sequence you described, I gather that your SADS was not disassembled when your head gasket job was done. If you went in with a bad head gasket and came out with a vibration, I can only speculate that something wasn't assembled carefully. I know that's of no help to you, and I'm sorry.

The Previa is a peculiar beast. That happens to be one reason they appeal to me, but only because I have committed to doing my own work. The comment about a typical dealer's ability to diagnose their peculiar problems is valid. My experience with my local Toyota dealer is that I can't get past the service manager to speak with the individual mechanics. There may well be a Previa expert back there, but they keep him/her busy working on the newer cars that demand their special expertise as well (and belong to recent new-car purchasers). I've been happy with my local dealer, but I only use them for well-defined tasks on my wife's Avalon that I don't want to fuss with myself.

Independent shops vary wildly in quality. Many are well run and reasonably competent, and many are crooks. A few specialize in particular cars. If there were an abundance of Previa specialty shops competing for business, there would be some good ones. VW shops were abundant when there were bazillions of VWs buzzing around. But that isn't the case for Previas, and won't be, ever, because there just aren't that many Previas being saved from the crusher. Your experience speaks to why that is the case.

People often ask me how to choose a good used car. I tell them to first figure out where they're going to have it worked on.

Just wanted to update you on what I learned this morning. The mechanic who did the head gasket put the car up on the lift and told me the front and rear "triangle" (flanges?) had marks, like someone marked them before removal, however the front and the rear were not aligned. One was "about 8 degrees" off from the other. I interpret this to be like 20 minutes on a clock? Also, I spoke with a driveshaft company in Colorado, who has an ad on the internet for selling refurbished Previa driveshafts that are "high speed balanced" and they told me it is important to have every shaft that is removed from the car, rebalanced before it goes back on. The amount the shaft is out of balance, will affect how long the couplers will last. So maybe the home installers who use the aluminum couplers are only getting X number of miles out of them, because they don't "perfectly" balance the shaft before re-installing it, I don't know, just a theory. Given that I could find NO shop that does that job anymore, it seems like a plausible assumption. So I think my issues are a combination of 1)the shaft not being rebalanced after coupler replacement by the driveline shop and 2)the driveline shop did not realign the triangle (flange) components to each other between the front and the rear per their own marks.

[previagal]

Here is the latest after taking the car back this morning to the head gasket shop, because the overdrive light came on again, of course Friday at 6pm. LOL No car all weekend. I'm sure getting in good shape riding my bike in 90 degree heat through all the days of car problems! I also brought the factory manuals with me, to show the mechanic about letting the shaft hang, and also asked him to look at the coupler installation TSB (which Tim kindly furnished, thank you that was very helpful for me and the mechanic - too bad the driveline shop didn't look at it.)and look at the coupler/assembly of those parts to see if they were marked by the driveline shop. What he said was on the "triangles" which (I think) they're calling the flanges in the service manual, there were marks, but the one on the engine side did not line up with the ones on the balancer side, He said they were about "8 degrees" ( I guess like 20 minutes on a clock) offset to each other. This was absolutely the fault of the driveline shop, since they were the ones who took these particular components apart. Also, this morning when I left the car, I left the service bulletin and the factory manual, and showed him the pages where it says support the shaft etc. He argued this morning, but (I think) after reading what I had highlighted with yellow, which was the part about don't leave the shaft unsupported "for a long period", he admitted when I came back to pick the car up, that he had left it unsupported for five days, and now understands that was wrong. What I have found in making assertion messages like that one about supporting the shaft, is that people will always reject them at first and get defensive. So the key is to calmly keep repeating the message, and eventually, reasonable people will allow it to seep into their previously held ideas. And that is exactly what happened! Geez, I was so happy he admitted and understood the original problem :) So I told him my plan to provide the OE couplers to Colorado Driveshaft and he said he would absolutely "be very careful" when he installs the new shaft and install it completely to the factory spec. Tim, I hear you about alignment and mounts, I did point out this morning, that the shaft needs to have no more than a 2 degree angle between the front and back on each side of the front coupler. When I went to pick the car up, my mechanic said he didn't have the tool to do that measurement, because I asked him to check to see if the driveline shop by some chance messed that up. Anyway, the next task is for me to find that tool and buy it. (unless it's a thousand bucks which I can't imagine.) The factory manual refers to it as SST Angle Gauge 09370-50010. SST = Special Service Tool. This is also found in the 2007 Lexus Special Service Tool PDF on the 5th page in the sequence of pages on the PDF, but on Pg 3 in the document pagination at the bottom of each page. I highlighted it in yellow. I found a phone number on the web for a company called SPX/OTC, and when you call that number (800-933-8335) one of two options is for Toyota Special Service tools.
They didn't have pricing when I called so they're going to call me back. I'm hoping that the reason their computer shows no pricing is not because it's no longer available. :doh: If that's the case, I'm not sure about where to go on that one, since the dealer told me they don't have the balancing equipment, maybe they don't have this driveline angle tool either. Although I found it on Amazon as a generic tool, so maybe it's generic and not specific to the SAD. Fingers crossed.

1902
1904

(I hope whoever needs the SST tool can access those PDFs. One shows up as a link the other shows up as an attachment. I can understand the technical manual etc, but I'm a spaz when it comes to using the attach file function on here. :rol:

[previagal]

UPDATE ON SPECIAL SERVICE TOOL SOURCE: I just called Kent-Moore, the person who answered the phone there told me Kent-Moore is "under the same umbrella" as SPX/OTC and gets their Special Service Tools from the same source as the SPX/OTC company I listed in my first reply.

That SST Angle Gauge "diagram" pdf I attached, looks like a stick with a string on it, and they show two of them on the shaft at the same time in the Factory Previa manual, one is shorter, so does that mean you use two? The Lexus suggestion for "equipment" used with this part number looks like:

Dial Indicator with magnetic base
Torque Wrench
V-Block
Vernier Calipers.

The Lexus application is the same Angle Gauge and part number as shown in the Previa book, but it is indicated for Lexus to be used on the propeller shaft, which is different from the SAD.
Does this (Link below) look like something that can be used on the SAD to measure the angle in front of and behind the front coupler, without the "stick" SST? What is the stick for, or does that job require both? The Previa Factory manual does not show a dial indicator in their illustration, they only show the stick with what looks like a plumb line and a weight, which seems like it would be pretty primitive since if that's all there is, whether it is hanging straight would be subjective based on who is looking and could they see a 2 degree variation with the human eye?

http://www.harborfreight.com/dial-gauge-angle-finder-34214.html

[timsrv]

Yes, as with most of the SSTs this one looks like you could make something or substitute something else. As a Toyota tech, I think I only purchased 2 or 3 SSTs over my career. The only advantage with theirs would be if it came with detailed instructions, but I'm guessing it won't (refer to service manual). If it has to be just like theirs, get a plumb bob and a ruler & draw some lines on the end :)>:. Tim

[previagal]

Yes, as with most of the SSTs this one looks like you could make something or substitute something else. As a Toyota tech, I think I only purchased 2 or 3 SSTs over my career. The only advantage with theirs would be if it came with detailed instructions, but I'm guessing it won't (refer to service manual). If it has to be just like theirs, get a plumb bob and a ruler & draw some lines on the end :)>:. Tim

After thinking about it more, it seems like it should have vertical lines on the stick. Like if the string hanging down doesn't hang perfectly parallel, then you adjust the shaft so it does. But again, whether the tech is holding the stick straight or not,or eyeballing whether the string is perfectly parallel to the lines is subjective.
What a mickey mouse "tool." :clap: Seems like that magnetic dial gauge would be more accurate. I'd use both and measure them against each other, if it were me. :) I wonder why the Lexus paper listed the dial indicator, as "equipment" to be used with this "tool"? But again, the Lexus application is for a propeller shaft, not the SAD.

[pdgizwiz]

The SST does indeed look like a stick with a string. I believe it is a combination protractor/plumb bob. Such a contraption could be used to measure angles accurately enough to determine whether two things were parallel or not, provided that those to things had nice cylindrical surfaces to use as references and that one had access to them.

The string in the picture appears to have a weight attached to the end that looks like a carpenter's plumb-bob, so that it will hang straight down. The end of the tool must be squared off and held against the item having it's orientation measured. The same tool is used to measure that angle at two locations and the readings are compared to see if the difference is less than two degrees or not. Gravity provides the reference. I expect the string hangs from a pin, or is through a hole in the stick at a particular point. At the other end of the stick I would expect a scale, marked off in degrees, located at a specific distance from the hole/pin that the sting hangs from.
I can't imagine why the two sticks in the picture appear to be different lengths. I expect that the graphic artist who drew the figure never took pre-calculus and had no concept of trigonometry. Not to worry.

There are 90 degrees in a right, or "square" angle. Four right angles make one full revolution.

I'll use your "clock" reference, where there are 60 minutes in a full revolution of the minute hand. Let's leave aside the fact that to a surveyor or architect, each degree can be divided into 60 "minutes of arc" and each "minute" can be divided into 60 "seconds of arc". Forget that for now.

Back to the clock, the minute hand moves 90 degrees in 15 minutes. How many minutes pass if the hand rotates by 2 degrees?

Two of the 90 degrees are 2/90, or 1/45 of that fifteen minutes on the clock. So 1/45 * 15 = 15/45, or 1/3 of a minute. That would be very hard to see on a wrist watch, but not on Big Ben. Imagine that SST stick to be one sliver of the face of a much larger clock, say a foot in diameter. Zoom in on the spot where the minutes hand goes by the outside of the clock, and the distance between the marks that divide the minutes get bigger.

If you place a chunk of a ruler 14 5/16" away from the pivot of the string, each whole degree will be separated by a quarter of an inch. Each 16th of an inch will be 1/4 of a degree apart. if you make you stick twice as long, or 28 5/8" between the sting pivot and the scale, your precision will double.

The end of the stick must be cut square. Hold that square edge against the SADS tube, let the string dangle freely until it stops on a mark, and remember or record which mark that is. Now do the same thing on the other portion of the SADS and compare the two readings. But wait! There's really no adequate way to get your stick on a cylindrical surface of the front portion! The FSM really fails here. Fortunately, the drive housing is a nice burly iron casting with a couple of flat surfaces on its lower face that are perpendicular to to the bearing flange and thus parallel to the axis of the front portion of the shaft. I have a van in the air right now, so I'll cobble up a tool and post a design in the next day or two. Please stay tuned.

Mickey mouse, maybe, but if used carefully it could be quite accurate. It's easier for me to see how this thing could do it's job than a dial indicator, which is generally used to measure run-out or concentricity, and not an angle.

[previagal]

The SST does indeed look like a stick with a string. I believe it is a combination protractor/plumb bob. Such a contraption could be used to measure angles accurately enough to determine whether two things were parallel or not, provided that those to things had nice cylindrical surfaces to use as references and that one had access to them.

The string in the picture appears to have a weight attached to the end that looks like a carpenter's plumb-bob, so that it will hang straight down. The end of the tool must be squared off and held against the item having it's orientation measured. The same tool is used to measure that angle at two locations and the readings are compared to see if the difference is less than two degrees or not. Gravity provides the reference. I expect the string hangs from a pin, or is through a hole in the stick at a particular point. At the other end of the stick I would expect a scale, marked off in degrees, located at a specific distance from the hole/pin that the sting hangs from.
I can't imagine why the two sticks in the picture appear to be different lengths. I expect that the graphic artist who drew the figure never took pre-calculus and had no concept of trigonometry. Not to worry.

There are 90 degrees in a right, or "square" angle. Four right angles make one full revolution.

I'll use your "clock" reference, where there are 60 minutes in a full revolution of the minute hand. Let's leave aside the fact that to a surveyor or architect, each degree can be divided into 60 "minutes of arc" and each "minute" can be divided into 60 "seconds of arc". Forget that for now.

Back to the clock, the minute hand moves 90 degrees in 15 minutes. How many minutes pass if the hand rotates by 2 degrees?

Two of the 90 degrees are 2/90, or 1/45 of that fifteen minutes on the clock. So 1/45 * 15 = 15/45, or 1/3 of a minute. That would be very hard to see on a wrist watch, but not on Big Ben. Imagine that SST stick to be one sliver of the face of a much larger clock, say a foot in diameter. Zoom in on the spot where the minutes hand goes by the outside of the clock, and the distance between the marks that divide the minutes get bigger.

If you place a chunk of a ruler 14 5/16" away from the pivot of the string, each whole degree will be separated by a quarter of an inch. Each 16th of an inch will be 1/4 of a degree apart. if you make you stick twice as long, or 28 5/8" between the sting pivot and the scale, your precision will double.

The end of the stick must be cut square. Hold that square edge against the SADS tube, let the string dangle freely until it stops on a mark, and remember or record which mark that is. Now do the same thing on the other portion of the SADS and compare the two readings. But wait! There's really no adequate way to get your stick on a cylindrical surface of the front portion! The FSM really fails here. Fortunately, the drive housing is a nice burly iron casting with a couple of flat surfaces on its lower face that are perpendicular to to the bearing flange and thus parallel to the axis of the front portion of the shaft. I have a van in the air right now, so I'll cobble up a tool and post a design in the next day or two. Please stay tuned.

Mickey mouse, maybe, but if used carefully it could be quite accurate. It's easier for me to see how this thing could do it's job than a dial indicator, which is generally used to measure run-out or concentricity, and not an angle.

Thank you! that's a great explanation of how to calculate degrees in relation to increments on the clock. One question though, (brain is feeling fried as each new issue brings up more questions in my pea brain LOL :o), if there are only three bolt holes on the "triangle" (flange), how can it only be 8 degrees off? Wouldn't it be off the entire distance between the bolt holes?

I'm going to print out your instructions on how to use that stick (cracks me up every time I think of it as "the stick")and leave them on the seat with the stick when I drop the car off to have the new shaft installed. I can't overwhelm the mechanic anymore with lengthy verbal explanations, but he can read it and I'm sure he'd pick up on it faster than I would since he can actually look at where it's supposed to go. One other thing, when I looked at the shaft assembly with the car up on the lift, it looked like there was junk (not sure what it was) in the way of hanging that stick straight down from in front of the coupler. I didn't know there was a housing there until I looked at the book again this morning to see where those "stays" were, so I didn't notice it when I saw the front of the shaft when it was on the lift.

[timsrv]

Each possible location on the SADS is 120 deg apart (3 X 120 = 360).

[previagal]

Each possible location on the SADS is 120 deg apart (3 X 120 = 360).

Then my mechanic must've been wrong when he said 8 degrees? :wall: He seemed very confident in making this statement and it seemed like he really believed the "triangles" were not lined up between the front one and the back one, which is what he said it looked like. I don't know, maybe he was lying to cover his own butt for letting the shaft hang for 5 days -- based on how he argued this morning though that the shaft does not need to be supported, maybe he was lying about the triangles being 8 degrees off. Or is it possible the way the driveline shop installed the couplers, they could have moved 8 degrees? Could this have happened if they'd installed the newer/bigger diameter insert couplers? This shop however, has 100% reputation over many years, for honesty.
Cannot make any ASSumptions, because I have no clue whether what he said is the truth or not, but after thinking about the 8 degrees claim in relation to the 120 degree distance between the bolt holes, holy hell, it's SO confusing. LOL~! Although he was looking down the shaft with it still in the car, so how accurate could that be?
All I know is, I'm getting a new one, who lied or who didn't do a good job is not important anymore as far as who caused what (other than all this great education I got on what it actually looks like and how it was *supposed* to be.) I can only hope he does a good job on the install. I think he's aware now of the proper procedure, and stated he was going to be "really careful" with the new one, and knows now that I know what's going on, so that's in my favor. You know how us human beings are--as long as there's hope, we keep trying. LOL

[timsrv]

I don't know. I don't think anybody was lying.......just an observation regarding possible locations. Maybe he meant the front of the shaft wasn't aligned with the back of the shaft (like the shaft got twisted or something)..........who knows. Like you said you're getting a whole different shaft, and your guy sounds like he's on board with correct installation.

Regarding drive line shops, it's hard to imagine this not being something they could handle. I was thinking about this and realized if I ran a drive-line shop I would live for unique and challenging jobs like this (how boring would it be if all you got to do was run the machine like a trained monkey?). Sure, the 1st one would throw you for a loop, but with a little ingenuity you could balance anything that fell within the length/diameter restrictions of the machine. Whatever happened to the guys that used to run shops like this? This is disappointing. We used to be able do anything in America. Makes me want to buy a $50k machine and start tooling up :LOL2:. Tim

[pdgizwiz]

Wow, you guys burn the midnight oil.
I agree that 8 degrees doesn't make much sense. It's hard to imagine the SADS taking a bend like that while installed. If the front drive housing was that cattywompus, then surely things would shake like crazy. But this is probably more of a misunderstanding somewhere along the line than a lie. Maybe he was saying that it was at 8 degrees while it was hanging loose?

Dynamic balancing machinery is fairly sophisticated. Those shops that have it probably do 99% of their business (if not 100%) doing conventional driveshafts for the off-road and custom hot-rod market, so that's what they're tooled up to do. If Colorado Driveline is tooled to do Previa SAD shafts, they have a niche. Naturally they will tell you that their service is absolutely essential, and that people like Tim and myself who have just swapped couplers with success are just lucky. Maybe so. If there was a local shop that I could take a SADS to for dynamic balancing for less than $100, then I'd likely do it. But so long as my luck holds....

Many moons ago I had an Alfa Romeo Alfetta. Its engine is in front, but the clutch and transmission are in the back. They were connected with a driveshaft that ran at engine rpm all of the time, had two rubber donut couplings and a center bearing. I had to replace the couplings, and couldn't find anyone to balance the shaft locally for similar reasons. And it needed it. I'm sure there was someplace in the country where I could have plunked down a grand for a complete shaft assembly, but that wasn't in my budget. I managed to do it myself with a pair of hose clamps and a lot of trial and error, but I never got it perfect. I could still feel a slight vibration at around 2200 rpm. I let a died-in-the-wool Alfisti friend of mine drive it one day, and when he got back, I asked him if he felt that slight buzz at 2200 rpm. He said "No, I never let the engine go below 4000". I knew then that the car wasn't for me and sold it soon afterwards.

[previagal]

Wow, you guys burn the midnight oil.
I agree that 8 degrees doesn't make much sense. It's hard to imagine the SADS taking a bend like that while installed. If the front drive housing was that cattywompus, then surely things would shake like crazy. But this is probably more of a misunderstanding somewhere along the line than a lie. Maybe he was saying that it was at 8 degrees while it was hanging loose?

Dynamic balancing machinery is fairly sophisticated. Those shops that have it probably do 99% of their business (if not 100%) doing conventional driveshafts for the off-road and custom hot-rod market, so that's what they're tooled up to do. If Colorado Driveline is tooled to do Previa SAD shafts, they have a niche. Naturally they will tell you that their service is absolutely essential, and that people like Tim and myself who have just swapped couplers with success are just lucky. Maybe so. If there was a local shop that I could take a SADS to for dynamic balancing for less than $100, then I'd likely do it. But so long as my luck holds....

Many moons ago I had an Alfa Romeo Alfetta. Its engine is in front, but the clutch and transmission are in the back. They were connected with a driveshaft that ran at engine rpm all of the time, had two rubber donut couplings and a center bearing. I had to replace the couplings, and couldn't find anyone to balance the shaft locally for similar reasons. And it needed it. I'm sure there was someplace in the country where I could have plunked down a grand for a complete shaft assembly, but that wasn't in my budget. I managed to do it myself with a pair of hose clamps and a lot of trial and error, but I never got it perfect. I could still feel a slight vibration at around 2200 rpm. I let a died-in-the-wool Alfisti friend of mine drive it one day, and when he got back, I asked him if he felt that slight buzz at 2200 rpm. He said "No, I never let the engine go below 4000". I knew then that the car wasn't for me and sold it soon afterwards.

I'm becoming weary with all of the problems since the head gasket. Not only am I still dealing with the shaft issue (Colorado Driveline just emailed me saying "Let me look at my cores so you can see what size couplers to get from Toyota" but there is a driveability issue that has existed since getting the car back from the head gasket job. I guess Colorado Driveshaft doesn't know that Toyota only offers OE couplers in the larger size, so if they don't have a core in the newer size, I'll have to find one somewhere. I found one in a wrecking yard in San Jose for $100, but ran a carfax and it shows insurance company title as a total loss for an accident that happened this year. Which could mean anything, since I got in a front end accident in mine and it was only $1400 to fix and the insurance adjuster put a $4400 estimate on it which exceeds blue book. But another issue that they fixed yesterday was the OD light. Apparently the speed sensor wire got cut/gouged as it was cut halfway through and the wire inside the insulation was damaged and the head gasket mechanic said "that wasn't anything I touched during the head gasket" so who knows, maybe the driveline shop did it. In addition to the SAD and speed sensor problem, the car is bucking at higher speeds, like it would feel if it had a vacuum leak. this was very faint at first, but now it's getting worse. Any ideas on that one? I just feel bummed out about all this stuff now, I need to resolve these issues and get on with my life. If Colorado Drive shaft comes back and says they only have the smaller one, then I have to find one somewhere, have it shipped to them and hope it's not bent? Because most of these wrecking yard shafts are from cars that have been in accidents. That or they're the earlier models with the older/smaller coupler size.

[previagal]

I don't know. I don't think anybody was lying.......just an observation regarding possible locations. Maybe he meant the front of the shaft wasn't aligned with the back of the shaft (like the shaft got twisted or something)..........who knows. Like you said you're getting a whole different shaft, and your guy sounds like he's on board with correct installation.

Regarding drive line shops, it's hard to imagine this not being something they could handle. I was thinking about this and realized if I ran a drive-line shop I would live for unique and challenging jobs like this (how boring would it be if all you got to do was run the machine like a trained monkey?). Sure, the 1st one would throw you for a loop, but with a little ingenuity you could balance anything that fell within the length/diameter restrictions of the machine. Whatever happened to the guys that used to run shops like this? This is disappointing. We used to be able do anything in America. Makes me want to buy a $50k machine and start tooling up :LOL2:. Tim

Many don't have the work ethic we would hope they would have, and that "it's good enough" idea translates over to every area of their life that requires effort. I think like you said, people who are sharp, aren't working as mechanics, that or they're self employed where they can make more than what a mechanic gets paid. The other thing is, we're dealing in the murky world of technology and engineering, where 90% of the people out there just don't have the time or inclination to research the problems and they are the sheep in the wolves territory. If you're ignorant, you're at the mercy of whatever they tell you. Although the dealer especially in many cases is so completely ridiculous in what they tell you the problem(s) is(are) usually plural/kitchen sink effect, that a person would have to be completely clueless to buy into their "estimate" for repair(ing everything.)

I have a driveability issue on the van that has been there since first getting it back. It was faint at first, now getting worse. And by driveability I mean it feels like it has a vacuum leak at higher speeds, like it's "bucking" The mechanic seems to be ignoring it and I'm getting tired of taking the car back to them for all these issues. I was just there yesterday where they had to replace the speed sensor wire which somehow mysteriously got twisted and cut halfway through, but he "didn't touch that area during the head gasket job."
Any ideas on the bucking phenomena?

[timsrv]

Driveability issues suck. When it comes do diagnosing without hands-on, they suck worse. These often become jobs where multiple things are tested & "process of elimination" is required to identify. When it comes to Previa specific issues, the only real common one is the the o'ring for the distributor shaft. If this leaks it allows oil inside the distributor & the result is rough running. It's not that hard to check, Have your mechanic pull the distributor cap off next time it's on the rack. If there's oil inside, then you'll need that o-ring replaced. Tim

[previagal]

Driveability issues suck. When it comes do diagnosing without hands-on, they suck worse. These often become jobs where multiple things are tested & "process of elimination" is required to identify. When it comes to Previa specific issues, the only real common one is the the o'ring for the distributor shaft. If this leaks it allows oil inside the distributor & the result is rough running. It's not that hard to check, Have your mechanic pull the distributor cap off next time it's on the rack. If there's oil inside, then you'll need that o-ring replaced. Tim

I hope it's not the distributor. When I bought the car, the (former) mechanic (I moved out of that county) told me "the distributor is full of oil, you need a new one" and that was a few hundred dollar job. I have read since, that they can be cleaned and just a new O ring. However the new one he put in failed too (intermittent starting problem correctly diagnosed as distributor issue by current mechanic) when still under warranty and took it back to former mechanic and he put another one in at no charge. Both were Richporter. I'll have to look at my service records tonight when I go home, but it wasn't that long ago.

[pdgizwiz]

Wow. A new distributor when all you needed was a $2 O-ring. That's the work of a professional!

[previagal]

Wow. A new distributor when all you needed was a $2 O-ring. That's the work of a professional!

Yes, depressing isn't it? Did not know at the time, that O ring would have been the fix. Hundreds of dollars later.



NEWS UPDATE: I have found a shop in the Los Angeles area, who told me they've been in business since 1945 and have balanced "thousands" of Previa front shafts. So rather than spend $350 for a wrecking yard shaft, OE couplers, shipping to Colorado and back, I'm going to ask my mechanic to remove the shaft, I will drive it to the Los Angeles shop, have them do the balancing and bring it back to have my mechanic re-install it. This shop told me the balancing takes about an hour and is $60. I mean, how hard is it, they put it on a machine, and add/weld weights on different places on the shaft, just like tire places balance a wheel, correct?

When it starts coming up again in 30K miles (or maybe it will last longer since it's balanced) if this driveshaft shop is good, I can have my mechanic just send it there.

[previagal]

Got the shaft back, but got back after 5pm from Los Angeles. Took the shaft to the mechanic this morning, and it was installed exactly per the factory manual. *Seems* a little better, but not really. Car still has front end vibration. I am so completely bummed out about this, not sure what to do next. In reading the coupler assembly instructions, it states that no matter which side of the coupler the bolt head is, all must be tightened on the shaft side. So in other words, sometimes you hold the bolt head and tighten the nut, sometimes you hold the nut and tighten the bolt head. I don't know if the driveline shop did this, but the shop in LA yesterday told me two of the bolts on the engine side were in backward, so he turned those around and balanced it, and it is STILL VIBRATING.
I *could* buy the Colorado Driveshaft shaft and have it installed, but now I know that even if the shaft is perfectly balanced, other things can cause the vibration. BUT WHAT. ??????????????? How can this be? I am considering a lobotomy as my next option.
If Colorado Driveshop installs the OE couplers and does not do it right, tighten bolts per the TSB, their shaft could be perfectly balanced, and still vibrate.
Seriously, does everyone who does their own coupler replacement tighten all the bolts and nuts on the shaft side? Can this make a huge difference?
This is driving me crazier.

[pdgizwiz]

Ick. I can imagine your frustration.
Let's talk vibration. Can you feel the vibration with the car stationary, in neutral? If you only feel the vibration when the car is in motion, it's not the SADS.

If you can feel it when the van is not moving, in neutral, can you feel it at an idle, or only after you bring the engine up to some range of rpms? Does it go away if the engine runs even faster? If this is the case then you have a case of resonance.

Things vibrate when their mass (weight) and the stiffness of how they are mounted are poorly matched. They will vibrate the most at a specific frequency called the "resonant frequency". Generally this frequency increases as the stiffness goes up, or the mass goes down. Stuff like this is designed to have a resonant frequency higher than the inputs due to normal operation can provide. In this case the speed of the shaft, which is direly related to engine speed, is the input. If something spinning is not dynamically balanced, the center of its mass swings around the axis rather than staying on it, and the rate at which this swinging mass provides the input to the system. If the system has a resonant frequency that matches the rate that it's spinning at, the whole thing will vibrate in its mounts. There's no such thing as "perfect" balance, so if your system has a resonant frequency in the normal range of engine speed, even the slightest imbalance can cause a problem.

The accessory drive apparatus is mounted on three rubber mounts - two at the rear and one at the front. Perhaps one is broken? From under the car you should be able to pry on the drive assembly and see if you can make a crack open in the rubber of one of these things. They're all three fairly easy to see, once the plastic splash shield is out of the way.

If the rubber mounts that the drive housing are mounted in are broken, it's stiffness will be reduced, which will reduce its resonant frequency, possibly to a point where it will be excited by a rotating shaft, even if the degree of imbalance in that shaft is very small.

Other than such wild speculation there's not a lot I can offer, I'm afraid.

[previagal]

Ick. I can imagine your frustration.
Let's talk vibration. Can you feel the vibration with the car stationary, in neutral? If you only feel the vibration when the car is in motion, it's not the SADS.

If you can feel it when the van is not moving, in neutral, can you feel it at an idle, or only after you bring the engine up to some range of rpms? Does it go away if the engine runs even faster? If this is the case then you have a case of resonance.

Things vibrate when their mass (weight) and the stiffness of how they are mounted are poorly matched. They will vibrate the most at a specific frequency called the "resonant frequency". Generally this frequency increases as the stiffness goes up, or the mass goes down. Stuff like this is designed to have a resonant frequency higher than the inputs due to normal operation can provide. In this case the speed of the shaft, which is direly related to engine speed, is the input. If something spinning is not dynamically balanced, the center of its mass swings around the axis rather than staying on it, and the rate at which this swinging mass provides the input to the system. If the system has a resonant frequency that matches the rate that it's spinning at, the whole thing will vibrate in its mounts. There's no such thing as "perfect" balance, so if your system has a resonant frequency in the normal range of engine speed, even the slightest imbalance can cause a problem.

The accessory drive apparatus is mounted on three rubber mounts - two at the rear and one at the front. Perhaps one is broken? From under the car you should be able to pry on the drive assembly and see if you can make a crack open in the rubber of one of these things. They're all three fairly easy to see, once the plastic splash shield is out of the way.

If the rubber mounts that the drive housing are mounted in are broken, it's stiffness will be reduced, which will reduce its resonant frequency, possibly to a point where it will be excited by a rotating shaft, even if the degree of imbalance in that shaft is very small.

Other than such wild speculation there's not a lot I can offer, I'm afraid.

Thank you. Are you talking about the "equipment drive housing insulator" because that is the only thing I could find in the factory manual, that sounds like what you're talking about. It does show two in the back, and one in the front. Also, I'm assuming the shaft has to come out, to replace these? If they're even available. And seriously, how often do these insulators get broken/cracked? Would they get cracked if someone forced the shaft into the housing? Instead of lifting and turning the 60 degrees?

[pdgizwiz]

Yep, I think that's them.
Rubber parts die with age, heat and chemical attack. They could be damaged if someone horses on them over much, too, of course. I've not seen these particular parts fail on any Previa I've owned, but they're rubber, so they are vulnerable to failure.

[pdgizwiz]

Oh, and it's possible that they can be replaced without taking the shaft off. I don't know for sure, as I haven't had to do it, but they're right on the bottom of the drive housing and should be easy to get to.

[previagal]

Yep, I think that's them.
Rubber parts die with age, heat and chemical attack. They could be damaged if someone horses on them over much, too, of course. I've not seen these particular parts fail on any Previa I've owned, but they're rubber, so they are vulnerable to failure.

My mechanic said he followed the procedure in the book step by step, but I did see him using an impact wrench on something (I was in the waiting room, and the car was up on a lift, but I couldn't see under to see what he was using the impact wrench on, which bothered me, because these insulators, it says don't use an impact wrench. :o(

The only other thing I can think of to try, is the Special Service Tool SST, I mentioned before (the stick with the string) is needed to measure the angle on both sides of the front coupler. I called the dealer today to get that tool, they're supposed to call me back. I think they will have better luck getting it from OTC, because I haven't.

I'm almost afraid to go back to my mechanic with the "will you please check the insulators" question, he's so sick of this car, because he knows the whole problem started with him letting the shaft hang..... Also, after studying the illustrations a little more it looks like the book calls them No. 1 and No. 2 and they are all on the front. No.1 is two pieces, they are calling a LH and RH (one on each side). Then there is another insulator which doesn't look like it has any rubber, it just looks like a bracket in the book, they're calling that insulator No. 2. There isn't anything on the engine side, as far as I can see in the factory manual. My only question after looking at this more, is these insulators are bolted to the front driveshaft housing. Does that affect the shaft being off kilter when they aren't connected to the shaft itself? Sorry if this is a dumb question, but what exactly does the housing do?

1917

[pdgizwiz]

The rear one is labeled 16983, and the front ones are both 16982.
They are a composite construction, rubber molded onto steel plates with hardware, etc. They attach the big iron framework to which all of the accessories attach to the body of the car, isolating any vibrations between the car and the spinning gizmos (alternator, power steering pump, a/c compressor, and the supercharger on the later vans).
I think it's time you get dirty and wiggle under your van with a flashlight and a big screwdriver and find them for yourself. Bond with your van and not your mechanic. You can buy a pair of ramps, or park it with one side on a curb high enough to give you room to scoot underneath.
If you buy the SST, you will likely be astounded to spend a lot of money for a stick with a string and a few lines drawn on it. Spend that same money on a Factory Manual for your car on ebay.

[pdgizwiz]

The mounts are referred to as "insulators" in the FSM. There are several pictures showing how to deal with them, how not to install them, etc., in the "Cooling Sytem/Separated Accessory Drive" section.

[previagal]

The mounts are referred to as "insulators" in the FSM. There are several pictures showing how to deal with them, how not to install them, etc., in the "Cooling Sytem/Separated Accessory Drive" section.

Go back to page 5 in this forum. My last post already POSTED A PICTURE OF THESE INSULATORS (you first referred to them as mounts) and I found them almost immediately in my factory service manual the first time you brought them up.

All I can do is give the mechanic the xerox copy FROM MY FACTORY MANUAL and ask him to install per the factory spec. Which is exactly what I did, and what he said he did. And that was also what I did with the driveline shop. I gave the a print out of the TSB on how to install the couplers, and they messed it up, because they think they know it all and laughed in my face.

I'm not allowed to stand there breathing down the mechanic's neck, and supervising his every move, so if he didn't do it right, how am I supposed to know what he did?

[pdgizwiz]

Well, clearly I crossed the same line the TheMAN did, just before he stopped posting. Excuse the heck out of me.
These forums are for sharing advice and experience, not barbs and insults. Sometimes the two are confused. Since I am of little help with your clean-nails approach to auto repair, I'll make this my last post to this thread.

[previagal]

Well, clearly I crossed the same line the TheMAN did, just before he stopped posting. Excuse the heck out of me.
These forums are for sharing advice and experience, not barbs and insults. Sometimes the two are confused. Since I am of little help with your clean-nails approach to auto repair, I'll make this my last post to this thread.

I'm sorry if my reply sounded rude and I know you were trying to help and I appreciate it--- your timing was a little off for comments like those however, after I've been posting in here for a few weeks now, posting every development, and am at this point just completely depressed about this whole thing, and not sure what to do next. I have no support system or help of any kind except this forum. I came in here for technical advice and I got it, and even though the problem is not solved, I now understand exactly what's going on. If I had the tools and a place to do this job, I could probably do it from memory (and would), I've studied the TSB and factory manual so much.
I have no aversion to getting dirty, it's not about clean nails. The reality is, I have no place to do my own work, no tools and no machine shop. I am also nursing a torn tendon in my ring finger on my right hand, which has been going on for months and makes it hard to grab anything with any decent grip. You think it's easy because you probably have a work bench with a vice to replace your own couplers, a garage to leave the car on ramps, I have none of those things, and even if I went out and bought a vice, torque wrenches, whatever other tools I'd need, I cannot do this job on a public street. Maybe if I lived in the slums, but that isn't where I live. I took the (dirty) shaft to a driveshaft shop 80 miles from my house, hung around in a bad neighborhood for two hours and then drove it back. All of the people who worked on my car got the interior steering wheel and floor mats full of grease. My hands were black after driving a mile, and my shoes were also greasy.It took me an hour to scrub all the grease out of both front floor mats. I check my own oil, and other fluids, check tire pressure etc. That is about as hands on as I can get. If I had a place to do this work, I would attempt it, but I don't and I'm not going to do it on a public street. You are also wrong about a used car being wrong for me, since my only other option is walking or riding my bike due to not being able to afford anything newer, and that isn't just me, it's a lot of people in this funky economy. I have a masters degree and have been submitting my resume without luck, since losing my job over two years ago. It's a used car, or no car. And no car means no way to keep looking for work. During these repairs, I rode my bike 200+ miles, in 95 degree heat. I went into this head gasket job trusting the mechanic, because he said he'd done "20 of these Previa head gaskets" and he messed the shaft up.
I'm approaching the original problem of the messed up shaft, the only way I know how, trying to educate myself so I can understand what the mechanics are doing, asking them to follow the factory procedures (which they don't do), and trying not to get ripped off, which happens anyway, because people working on cars act like they know it all and are unwilling to consider the factory procedures. If I went to the dealer, it is a bigger rip off.
You are right about this forum being about sharing advice and experience, and I have learned so much in here which I'm very appreciative of,so it has served it's purpose.
Since getting the car back yesterday after the driveline shop 80 miles away balanced the shaft, and my mechanic putting it back in the car, the vibration is worse. Deductive reasoning tells me the issue now must be something wrong with the installation, since the shaft is now balanced, and the distant driveline shop corrected the two bolts the local driveline shop installed backwards. I will find someone who will check the insulators per your suggestion, and someone out there must be able to measure the angles in front of and behind the front coupler. Other than that, I don't see there is much other options, because I cannot R&R the shaft myself.

[djshimon]

Maybe something more simple like bad tires-bubble in the tire or out of balance.

[Burntboot]

PG - I am with DJ on this one, sometimes we can get focused on something that we think is the problem but really isn't, BTDT, (way more than once, I am afraid.)

That being said, if you fix something once, twice and again and it doesn't get better, there is a small possibility that you fixing the wrong bit.
Not saying thats your issue here, just something that might be worth considering.

As an aside, not all of us have access to the latest and greatest, while I currently have a driveway, it wasn't always so, but it still sucks when it's -30C or snowing or raining, best of all though is when it's doing all 3, especially if you're doing something FUN like pulling a tranny (also BTDT), Fun, WOW!
I found a reasonable solution was to make a friend, buy beer and enlist their "help".
BB

[previagal]

PG - I am with DJ on this one, sometimes we can get focused on something that we think is the problem but really isn't, BTDT, (way more than once, I am afraid.)

That being said, if you fix something once, twice and again and it doesn't get better, there is a small possibility that you fixing the wrong bit.
Not saying thats your issue here, just something that might be worth considering.

As an aside, not all of us have access to the latest and greatest, while I currently have a driveway, it wasn't always so, but it still sucks when it's -30C or snowing or raining, best of all though is when it's doing all 3, especially if you're doing something FUN like pulling a tranny (also BTDT), Fun, WOW!
I found a reasonable solution was to make a friend, buy beer and enlist their "help".
BB

I am 100% sure it is the accessory shaft. This front end vibration is very common with the Previa, it did not exist before they disconnected it to drop the engine and let it hang unsupported for five days while the engine is out. ....it happens, especially when there are too many hands in the pie, and the R&R/coupler replacement requires specific precautions. The latest development is that the mechanic who did the head gasket is now saying he doesn't want to work on the car anymore, even though he's the one who caused the problem. I sort of don't blame him really, the cause of the vibration is hard to track down, when you don't know what others did, and I know he tried his best. My latest strategy is I have an appointment with the dealer on Tuesday, to replace the insulators, which are the rubber baby buggy bumpers that the driveshaft housing sits on, and they dampen the vibration from all of the peripherals. The parts are $89, the install is $160. It's my last hope before biting the bullet and going with a Colorado Driveshaft refurb, with OE couplers. The dealer said they will install, but no guarantee, which makes me nervous, since if they don't install it correctly, and still have the vibration, I'm out all that $$ again. I wish I had a garage. I'd do the dern thing myself. Maybe I will run an ad in craigslist, and see if, like you suggested, I can find someone who will allow me to use their garage to do this job myself. I really don't have any friends I can hit up, and most of the people I know don't drink. Although I really don't have time to stumble through mechanic work and don't want to. I know that sounds lame, but it always turns into a much more time consuming and complicated thing than we think it will be, and I've already lost a lot of time/work/income due to these car problems. Better now than in the winter though, I don't know how anyone can do thatkind of knuckle-skinning work in a garage in freezing temps.