Slight Differential Noise at 315K

[mahleek87]

Hey yall, just recently changed my differential oil after I believe after 60K, because I believe the last time I did it I had around 260-270K miles. Now I have 315,000 miles on my 86 van 2wd. My mechanic put 80W90 oil in the differential and while I feel that the vehicle performs a tad bit better there is a slight humming noise that I have noticed. I took it back to my mechanic and he said it was a diff noise because its so old. He said probably all the debris/etc that came out of my oil change is the reason there is a slight noise now with new fresh oil. He was telling me that companies make a oil additive product which you can put in side diff to quiet it down, I believe it may thicken up the oil. Im really hesitant to additives etc, but I believe in this case it may be fine? With the mileage and everything into consideration, what do you guys think? Keep on driving it without adding the additive or what?

[timsrv]

Nothing wrong with 80W90, but I personally like to use synthetics in my gear boxes due to the fact they don't burn it and it will most likely be there for a very long time. If I was trying to quiet down a gear box I might use Power Punch as it clings to the gears more and reduces noise. I'm not sure about additives, but don't see a problem using them on old/worn gearboxes.

An old trick used by unscrupulous car sellers was to put sawdust into noisy gearboxes. I'm sure it led to an early demise, but it worked well for quieting things down :rol:. Tim

[mahleek87]

Is it to late to switch to synthetic gear oil?
Whats your thoughts on using a thicker weight
Oil like 140weight for the differential? I read that
It should quiet it down.

[kcg795]

It's probably due for a rebuild. Remember I had to have mine done?

[timsrv]

Is it to late to switch to synthetic gear oil?
Whats your thoughts on using a thicker weight
Oil like 140weight for the differential? I read that
It should quiet it down.

The way I look at it is: What do you have to lose? The thing is old and failing anyhow so even if it does nothing it's only a quart of gear oil invested. I don't think any of it costs more than $20 per qt.........but KC has a point, it's probably just a matter of time (regardless what you do).....but how long??? I've ran noisy gear-boxes before. It really amazes me how long these things can go for. My 92 Previa had a noisy differential when I bought it. I put 20k miles on it and it didn't get any worse. Tim

[kcg795]

Here's the noise mine was making. Oh man, listening to my stereo on camera is kinda depressing. Miss that system. Thieves need to go die in a fire. Anyway, if this is the noise your Van is making, get ready to fork out $900 to have a mechanic rebuild it. After mine was rebuilt, it still makes some noise when I take my foot off the gas. Mechanic said it was normal since the new parts are going to force the gears to mesh in a slightly different pattern.


http://www.youtube.com/watch?v=a7CcaWZx3uM

[mahleek87]

Luckily mine isnt that bad.


TIM exactly what weight of synthetic oil do you recommend? What do you think about Weight 140? http://www.starbrite.com/productdetail.cfm?ID=1612&ProductCat=Automotive&ProductSCat=Gear%20Oils&ProductSSCat=140%20WT%20Gear%20Oil%20GL-1

Another mechanic said that 80w90 is too thin and I should switch to the Weight140 above to quiet the diff down. Should I use W140? Or switch to synthetic oil? And if I switch to synthetic which weight should I use? I wanted your expert opinion first.

[timsrv]

On an old gearbox that's noisy & loose, 140 wt should be fine.......should run quieter too. Tim

[Burntboot]

A little noise isn't a huge issue and thicker fluid may well take care of it for now, like Tim said, not much to lose at this point.

Just a side note - If you end up replacing it, it may well be worth trying your friendly neighbourhood dealer.
I had to deal with this in the spring, nothing used available, couldn't find a rebuilder and ended up going new.
As in brand spanking new, not rebuilt.
It was far from cheap at $1200, but US prices tend to be about half of what we pay, so it may be an option.
BB

[technocj]

The way I look at it is: What do you have to lose? The thing is old and failing anyhow so even if it does nothing it's only a quart of gear oil invested. I don't think any of it costs more than $20 per qt.........but KC has a point, it's probably just a matter of time (regardless what you do).....but how long??? I've ran noisy gear-boxes before. It really amazes me how long these things can go for. My 92 Previa had a noisy differential when I bought it. I put 20k miles on it and it didn't get any worse. Tim

I had a similar noise, starting at about 45mph, it stopped when i applied the brakes. I thought it was the diff, but it was rear wheel bearings.

[zeratool]

Check out JustDifferentials.com. They are in Casmere, WA and sell toyota.

[mahleek87]

http://www.redlineoil.com/Products.aspx?pcid=4


Hey Tim and all

Which oil out of those Redline differential oils should I use? I was thinking between 80W140, or Heavy Shock Proof. Red line oils are fully synthetic and i have had some great results in my other car with them. I wanted your expert opinion before I go ahead and order.

[timsrv]

I don't know. I'm sure it's a good product. Whatever you do is sort of a "hail Mary" anyhow so who knows how much good anything would do. IMO it's worth a try. Tim

[mahleek87]

Im at 336K, it has been 21,000 miles and the noise has remained consistent. Hasnt gotten louder or quieter. At 315k when I noticed the noise, I put this oil in the rear, 80W140 GL-5 Gear Oil Redline brand full synthetic. It really seemed to help. Im thinking about getting a used diff out of a van that has 210,000 miles up in PA. Although there doesnt really seem to be any issue to continue driving mine, I do miss that quiet smooth sailing sound. Any thoughts?

[Burntboot]

Differentials are funny things. Mileage isn't always an indicator of condition.
Just how well do you know this diff anyway?
Is this a blind date with a wrecking yard special or perhaps a meeting arranged between mutual friends that have your best interests at heart?

While I understand the desire to have a quiet ride again, I also know just how much fun swapping a diff can be.
Round these parts, a wrecking yard guarantee is that it is good, but if it isn't they'll get you another, labour not included.
If your paying for labour, it can get expensive fast.
On the other hand, if you KNOW the unit is solid, it may be a great idea.

Have you priced BOTH a new unit AND a rebuild (assuming you have someone local that is capable of the job).
You may even find new to be cheaper than rebuilt.
You may also find that the used part is that cost effective.
Out of curiosity, have you listened to your axle with a stethoscope, just to know exactly where the noise is coming from?

I am closely related to Murphy, every time I try to save a little green, it ALWAYS ends up biting me, hard.
The only thing worse than tossing large amounts of green on expensive shiny parts is saving a bit of green and getting something less than satisfactory,
and then doing it again. BTDT.
If you're basing your purchase based on the fact that it has lower mileage and therefore MUST be in better shape, you may be disappointed.
Caveat Emptor applies and due diligence MUST be exercised.
BB

[mahleek87]

Thx for your insight BB. The 210k van was being parted out. After reading what you said I found a van on eBay that's being parted out which has a little over 100k on it. I think I'll cross my fingers and go with that diff. It's reasonably priced too. $170 shipped. That being said people here in the area I'm from do not rebuild stuff. Dc md va. If they do they lie. It's an expensive area. Ill take my chances with the 100k diff and get it installed in a few months.

[MyToy]

Not sure if anyone still monitors this thread but maybe somebody has had my issue and can help.

got 275K on the van. All fine. then one day it started to produce a whirling sound from the rear end. It is more obvious between 20 and 35 MPH. When I come to a stop you can hear it all the way till it almost stops. So I jacked it up and ran the van. Got under and could hear the noise and it seemed that it was coming from where the drive shaft yoke enters the differential (MeatBall). This seal was replaced about 5K ago due to heavy leaking.
After looking at the FSM it looks like there are front and rear bearings right after this seal.

Has anyone had this noise issue?
Has anyone attempted to replace these bearings before?

Picture illustrates where I think the noise is coming from.

Thanks Guys

MT

[Burntboot]

Hey MT, sorry to hear about your noise.
Given the history (badly leaking seal) I suspect that its time for new parts, that said, have you checked the oil level?

For the record, things like pinion leaks are rarely caused by the "faulty seal", usually excessive play in the bearing allows the shaft to wobble around.
All that movement is what destroys the seal and replacing seals is at best a stop gap measure.
It is the first course of action cause sometimes a new seal will put up with more movement and putting off an expensive repair, perhaps forever, is a logical fist step.

As to the parts, yes, 2 bearings on the pinion shaft with a crush washer and if your doing the pinion bearings then you'll want to do the side bearings too (they've all been swimming in the same contaminated fluid) and you have to check gear wear and teeth patterns and preloads and ..........

There have been a few members the have redone their own, so it must be possible.
Though it is not a job for the faint of heart and I suspect there might be some incantations that need to be recited at same time.
I have known a few people who claimed to be capable and redid their own and suffered failures, so have just avoided the whole mess.

YMMV

[Burntboot]

"Meatball" lol, never heard it called that.

3rd member would be the standard common term, but we always referred to them as a "pig" (as it kinda resembles a pigs head in profile)

I have also seen used car dealers replace only the front bearing, in situ.
Its a repair on the order of sawdust in the gear case and wool sweaters under the valve cover.

Its kind of an all or nuthin affair.
Any short cuts deployed at this point will only increase (financial) pain in the long run.

[MyToy]

Yep, in my day it was a meatball. So I tend to still use the term.
When the seal was replaced I had caught it early and reloaded any oil in the unit as needed until I was able to get it to the shop. They monkeyed around with it quite a bit to get the seal in, so they say.
So I checked the level again and it is right up there with new clean oil.

A little history
I bought this van from the first owner who was amazingly sharp and took very good care of her. He was an engineer for Pratt. He had left it in a barn for 25 years pulling her out every so often to move the oil around after he topped all ports up for storage.

Then he gave me a list of everything done and fluids he used and recommend I stuck with. It was like reading the log books of an airplane, if you get my drift.

When the engine was overhauled the machine shop told me that it was a waste of time pulling it out and breaking it down. There was nothing wrong and well within tolerance. Like I said he really took care of this.

So now I have this rear end problem and my suspect is that the main stuff in the meatball (:lol:) are fine and that maybe you were right about the old bearing caused the seal to go. The sound sounds like it is coming right from the entry to the seal. But I have never done one of these and if I did, I would only do the front end of it if it was somewhat straight forward as it seems it is in the FSM. But before I attempted I thought I would ask the group. I would not even go to the main gears, way to deep for me.

So there you go.

Thanks again for the response.

MT

[Burntboot]

Hopefully someone with more experience chimes in.

I have never seen a fr bearing replacement that was successful, but that is hardly proof of a concept and possible I have only seen the results of idiots.

I have seen plenty of diff's ruined by well meaning tech's replacing a pinion seal but failing to mark things and put them back the same.
Overcranking the pinion nut can alter the backlash and cause failures. (Not suggesting thats what's going on with yours, though)

Maybe it's worth trying a mini-rehab, as there is little to lose at this point, but I would be on the hunt for a replacement, either way.

The other thing is, how slight is the noise, if barely audible it may be something you just learn to live with.
They will make noise for a LONG time before bad things happen (usually)

Might also be worth trying an additive??
I have some "Forte" diff and gear treatment left over from my dealer days, happy to toss one in the mail if ya want to give it a try.
Just PM me your co-ordinates.

It is as close to magic as I have ever found but, like hen's teeth, can be very hard to find.
Used to be factory recommended on Suzuki's back in the '90's and I have personally seen it quiet more than one noisy diff.
It isnt a repair, more of a (longterm) postponement, if it works.

[VanCo]

The bearing races for the pinion gear are hammered/pressed in and out of the third member. If you are replacing the bearings you need to replace the races. To do this you need to take it all apart. At that point you should also replace the side bearings too. The Timken bearing kit is about $180.

In the words of my Dad, "when you do a job big or small do it right or not at all."

[MyToy]

Thanks Guys:

Now I am in my thinking mode. Will make a call and let you know. Thank you so much for the offer. May take you up on it for sure.

[boogieman]

Nothing wrong with 80W90, but I personally like to use synthetics in my gear boxes due to the fact they don't burn it and it will most likely be there for a very long time. If I was trying to quiet down a gear box I might use Power Punch as it clings to the gears more and reduces noise. I'm not sure about additives, but don't see a problem using them on old/worn gearboxes.Tim

i know this thread is about rear diffs but i feel the term 'gearbox' can be misleading as theres quite some debate about modern gear oils, synthetics, and additives and their effect on 'yellow metals' in a transmission with synchros...i dumped the mobil1 full syn 80/90 that was in my transmission for this reason..and have 'maybe' noticed smoother shifting with dino oils...

[timsrv]

Yeah, I should have said differentials. There's a lengthy discussion here somewhere about our manual transmissions and the yellow metals within. It's worth mentioning the wrong gear oil can mess up our synchros. Nothing to worry about with our std diffs though. It's probably worth mentioning that some oils can mess with higher end diffs with posi and/or limited slip. Tim

[MyToy]

OK, well my transmission person told me it needs both front and rear bearings. Big job but reasonable for $300 labor. He wants to change out the carriage bearings and spacer at the same time. So while I am waiting for the parts I will jump back on my AC.
BurnBoot, thanks for the offer, but I think I am just going to get this done unless all these parts are not available. At that time I will decide to use your super oil. He will only use Totyota parts. He told me he wouldn't touch Rocks or any other non brand Toyota part. So I ordered them in and will see if they have them.

Thanks

MT

[Burntboot]

Glad to hear you're gonna do it right, should be good for another 300K

[Chardog1971]

keep us posted on the parts availability. just revived a 10+ year non runner and the rear end is growly. 250k on odometer. im thinking the heavier synth gear oil to start. hopefully I dont need to tear into it.

[MyToy]

Sorry for the delay in response.

All the parts were available . Cost about $270. $250 to install. All the list parts I put up in past mail was installed.

Finally got it done between jobs. Now totally silent.

MT