automatic transmission: delayed, jerky shifts. throttle (kick-down) cable adjustment?

[jbrush]

hi folks,

well, having finally dealt with the "emergency" issues on the van, i'm now trying to address an ongoing problem with the automatic transmission. in essence, it seems to have a delayed upshift, one result of which is that when there's significant throttle going from 1->2 there's usually a massive bang and shudder. sounds and feels awful! to avoid it, you have to remember to let off the gas near that point to let it shift normally.

also, there's some kind of leak of transmission fluid. got to the point recently that it was having a hard time shifting into reverse, but i'm keeping a better eye on it now. it's not obvious where the leak is coming from.

at any rate, one frequent suggestion for this kind of thing in the manual is to adjust the throttle cable. but i can't figure out where it means!

i at first imagined the "throttle cable" was what came from the accelerator pedal to the throttle body (but i think that's the accelerator link). or maybe they mean the kickdown cable that goes from the throttle body to the tranny. but neither seem to look at all like the pic below.

what am i missing? where is it (what part of the engine)?

thanks, y'all!
.brush

[JRSJ]

Before you start worrying about your throttle cable, be sure to check your air intake hose (the black hose in between the MAF and the Throttle body) for cracks. Vacuum leaks will cause rough shifting in lower gears. Check the seams and 'folds' of the hose, especially on the throttle body side of it.

Its recommend replacing the hose if its cracked, as a bad hose can stop a van in its tracks. You can use JBWeld or epoxy as a bandaid until you can find another hose.

As for leaky auto tranny? My van is a 5spd, so I wouldn't even know where to begin to look for ATF leaks. Me thinks it would be easy enough to track down though, being that most ATF is dyed. Try putting an oil absorbent pad out underneath your van overnight, and see what you can find.

[timsrv]

Yeah, I don't know why Toyota has to use such confusing terminology. What you or I would call the "throttle cable", they call the accelerator link. What you or I would call the "kick-down cable", they call the throttle cable . To put in laymen's terms, there are 2 cables going to your throttle body. The one on the top is the kick-down cable for the transmission, and that's the one you should be looking at. The 1st thing to do is step on the gas pedal and watch the kick-down cable. Make sure it extends and retracts correctly. If it's pulled out of the sheath and won't go back inside when the gas pedal is released, then your problem is definitely a bad kick-down cable. If it extends and retracts correctly, then disconnect it from the throttle body and operate it by hand. If it feels smooth and retracts under it's own power then hook it back up and adjust per the service manual.

Another thing that can cause hard shifts is the check balls in the valve body. They are made of plastic and over time they can shrink and cause problems. Harsh shifts aren't the worst thing, having the transmission slip between shifts is much worse and usually means the transmission is failing. If adjustment fails to cure the problem, just continue to "lighten-up" on the gas before the shift. Hope this helps. Tim

[jbrush]

wow, awesome late night responses!

ok, that makes sense: it's the kickdown cable, as i thought. but i can't figure out how to adjust it per the image i attached above. i finally found the "cable stopper" halfway inside the rubber boot -- it was way out of alignment per manual. however, when i remove the cable and pull on it, it seems to move freely but it stops hard while the cable stopper is still 1-2 cm inside the boot! so there's no way i can adjust the nuts to get it right. in fact, i adjusted it all the way from one side to the other of the adjustment nuts' reach -- and now the accelerator can't open the throttle all the way because the kickdown cable is stopping it!

any ideas what's going on? maybe tomorrow i go underneath and try to find where it connects to -- but i'm afraid it's inside the tranny box. is there somewhere else it might be getting bound up, or some other reason it's stopping "early"? maybe the cable stopper in the wrong place? incorrect boot length?

thanks, again!

[timsrv]

The correct adjustment should not be an extreme.....should fall somewhere in the middle. Without hand's-on it's hard to know what exactly is going on, but it shouldn't be interfering with the throttle travel. Try putting it back where it was originally and start the adjustment procedure again. If you are correctly following the directions and it can't be adjusted per the manual then it's a bad cable or something in the transmission. Unfortunately the other end of this cable is a PITA to access and replace (I've done it before). It is not a job for a newbie mechanic. Here's a link to a thread where we talk about it. Tim

http://www.toyotavantech.com/forum/s...months-sitting

[jbrush]

ok, here's an update. after pulling off the outer rubber covering, i realized that the cable covering had come out of the metal seat that it's supposed to fit into. after filing it down a bit to fit easier, i twisted it back in as far as i could, at least enough that i can pull the cable far enough that the cable stopper just peeks out of the boot. then i was able to adjust it "properly" w/o affecting throttle maximum. i'm not entirely sure that the lengths and distances are correct, and haven't had a chance to road-test yet, but it seems likely to work better than before!

still trying to figure out where ATF might be leaking. no big obvious patches, but there are some very slow drips formed on the back end of the transmission. there's also oily gunk spattered all over the underside of the vehicle, gas tank, etc. behind the transmission and along the drivetrain. there's at least one new part installed recently enough to still be shiny -- this metal bracket that has some kind of cylinder between it and the transmission? not sure what it is... kind of have the impression that the transmission was worked on recently (wish i knew more about the prior history) -- maybe even completely replaced with a used one?

any way, i haven't really gotten systematic about the leak yet... i won't be pulling the tranny myself (yet), but if there are other potential fixes or likely problem areas, would love to hear!

[jbrush]

ok, here's the update.

good news: adjusted kickdown means the shifts are at lower RPM, which is good for various reasons.

bad news: had little to no effect on the "bang and shudder" problem going from 1->2 with throttle, except perhaps it is a bit less bang and more shudder (ie. spread out over time a bit more). the problem persists even when i disconnect the kickdown entirely. at this point, we might just have to live with it. (maybe that valve body issue?)

however, a new symptom has also appeared (i think suddenly). the tachometer has started fluttering wildly when i push the gas down, usually around the 2k rpm zone. ie. the tachometer flits quickly up in RPM, then down, then up, then down, till i let off the gas. ie. as if the transmission was slipping badly. however, the sound of the engine stays consistent, moving slowly up and down (or even staying the same, going up a hill); ie. it feels fine.

any ideas what's going on? why would this suddenly have emerged? only other thing i did was tighten two belts (BTW, this is off topic, but how tight should belts be?). where does the tachometer get its signal? maybe some cable is pinched somewhere?

um... an update on the foregoing. as is doubtless obvious to most of y'all, i realize now that i must have tightened the alternator belt too much, resulting in a slipping tach. i don't have a torque wrench, but i gather the tension should be around 9 ft-lbs or so. i think i developed an overly aggressive sense of how little slack there should be, and did it by hand -- teaches me for trying to solve a non-existent "problem".

thanks, y'all.
.b

[happycloud]

So I am having a couple of issues on my 87 4YE 4wd van One is that my tranny shifts too high and jerky (I have to let go of gas to get it to shift "normally") and I am not sure of my idle adjustement. I understand that the tranny is adjusted by the kickdown cable but the only instructions I found are not relevant to what I see (there is another post here - guy had same issue - diagram in book refers adjusting cable until some stopper was in right place but I don't see anything like that).
The other is the idle - the book says to use a screw with a rubber stop - I don't seem to have that but I do see a screw near the top. However I had a buddy adjust my idle speed with the top cable so I am a little confused as to what is the correct way.

I've attached a pic of what I see. is #1 the idle screw? So how do I adjust the 2 cables?

Thanks!

[technocj]

I can tell you that #1 is indeed the idle adjustment screw.I would be very interested in the results of your tranny shifting issue, as my 86 2wd has a similar problem. There are 2 procedures I have seen for adjusting the cable, one using the stopper on the cable, one for a new cable that has no stopper. Neither one seems to completely cure my issue. I have an 85 that shifts perfectly, with 225 k on it.

[Rufus]

I have been experiencing this same issue with my "New" 1985 van with the automatic transmission. It wants to shift at a much higher RPM and later than it should. I adjusted the kickdown cable per the manual and it moves the threaded adjustment tube almost to one end completely on order for the stopper to be within the 0-1 mm limits at the edge of the boot. I drove it and after that adjustment it was shifting waaaaay too late and revving very high before it would shift. So I put it back where it was and then went a little way in the other direction and it was better but still not right. I am going to inspect it closer this weekend but something isn't right. The cable pulls smoothly by hand and the visible portion isn't frayed and there is no binding or dragging felt. I feel like the manual is right, I just cant't seem to make my vehicle conform. Help?

[vanalogs]

I have been experiencing this same issue with my "New" 1985 van with the automatic transmission. It wants to shift at a much higher RPM and later than it should. I adjusted the kickdown cable per the manual and it moves the threaded adjustment tube almost to one end completely on order for the stopper to be within the 0-1 mm limits at the edge of the boot. I drove it and after that adjustment it was shifting waaaaay too late and revving very high before it would shift. So I put it back where it was and then went a little way in the other direction and it was better but still not right. I am going to inspect it closer this weekend but something isn't right. The cable pulls smoothly by hand and the visible portion isn't frayed and there is no binding or dragging felt. I feel like the manual is right, I just cant't seem to make my vehicle conform. Help?

Good luck with the 85 transmission its a roflroflroflroflrofl

[Rufus]

The 1985 in particular? Why?

[vanalogs]

The 1985 in particular? Why?

I have had a hard time with the transmission in mine. Its different than the 86-89 trans (a44dl) which is the most common. Some people have put the a44dl trans into 3y 85 vans and it worked. Didn't work for mine it was jerky. I had to rebuild my 85 trans and cost $1100. I love my 85 though its a rad van runs the best out of all five toyota vans I've owned. Sadly just put it up for sale yesterday. http://losangeles.craigslist.org/lac...408961791.html

[timsrv]

Vanalogs, I tend to think you may have simply got a problem transmission. Several others have put the newer automatics into their vans without issue. Tim

[vanalogs]

Vanalogs, I tend to think you may have simply got a problem transmission. Several others have put the newer automatics into their vans without issue. Tim

Well Im still trying to sell it for $200 if theres any takers. Welcome to come and look at it

[happycloud]

I've got a similar issue unfortunately I don't have a rubber boot on my cable. Suggestions on how to adjust it? I've toyed around with it but not sure I have it right as my tranny doesn't quite shift as I think it should.

[JPERL]

With age The kick down cable tends to bind up in the sheath and not allow the cam where the other end of the cable is connected in the transmission to fully return to close the manual valve in the valve body and so this causes the transmission to shift late and backing off the accelerator does nothing because the cable is bound up.

Here is just a basic overview of how shifting occurs. There are other variables but this is basically how shifting occurs

There are two fluid pressures in the transmission working to cause upshifts and down shifts and its the battle of these pressures that determines upshift or down shift.

The pressure generated by the governor (attached to the output shaft of the trans) is built in response to vehicle speed

The pressure generated by the throttle valve increases in response to how much the throttle valve is opened.

When governor pressure exceeds throttle pressure an upshift occurs

When Throttle pressure exceeds governor pressure a downshift occurs.

In a full throttle start the upshifting is delayed because the throttle pressure is maxed out until the governor pressure built by the increase in vehicle speed overcomes throttle pressure to perform the upshift.

On a light acceleration there is far less throttle pressure to overcome and so the little speed generated by the governor overcomes the throttle pressure at a lower speed and thus lower rpm.

For example When your cable is bound up the manual valve in the trans could potentially be stuck 50% open from the get go and in order to upshift you would have to achieve a speed of 20-25 MPH (4900 RPM)for a 1-2 upshift.

The cable is discontinued from Toyota but I have an aftermarket source seauto.com that makes kickdown cables for the van and I have used them. PART Number is K83260

[happycloud]

Thanks for the info and part#. I dont see the part on the site - perhaps just call them? I am not sure my cable is bad though - it seems to flow well enough but not sure how to adjust it as it has no boot as indicated by the manual. Perhaps it's an aftermarket one. I wonder if I knew the size of the rubber boot if I could use that to adjust? Manual says 0-1mm from end of boot.

[JPERL]

Thanks for the info and part#. I dont see the part on the site - perhaps just call them? I am not sure my cable is bad though - it seems to flow well enough but not sure how to adjust it as it has no boot as indicated by the manual. Perhaps it's an aftermarket one. I wonder if I knew the size of the rubber boot if I could use that to adjust? Manual says 0-1mm from end of boot.

Yes call them and speak with Bernard.

As far as the adjustment goes using the 1mm stopper in relation to the boot when the cable is fully extended becomes irrelevant and is not a reliable indicator as these cables "stretch" over time. New replacement cables when they were available did not have this stopper staked to the cable.

I adjust it by feel. The following is my guide that I have used for years for upshifts

25% throttle 1-2 @ 10 mph 2-3 @ 25 mph 3-OD @ 30 mph

50% throttle 1-2 @ 15 mph 2-3 @ 30 mph 3-OD @ 35 mph

75% Throttle 1-2 @ 20 mph 2-3 @ 35 mph 3- OD@ 40 mph

100% throttle 1-2 @ 28 mph 2-3 @ 50 mph

According to the manual a 3-OD upshift will never occur with a throttle opening of 86% or greater

Hint when the cable is adjusted so that it is closer to the driver side will make the transmission up shift sooner.

If you adjust the cable until there is no threads showing below the red arrow you should get early up shifts

if you adjust the cable until the there is no threads showing below the blue arrow and the adjusting nut is touching the boot you will get very late up shifts

if you notice I have about 4.5 threads on the red arrow side and about 5 threads on the blue arrow sides basically I am adjusted right in the middle and that pretty much works if you have a healthy cable. This where I Have had most of my Vans adjusted

[JPERL]

UPDATE : Part number changed. Here is the contact for Bernard. The replacement cable is longer but it works fine. Just make sure it is not kinked when installed and the cost is 50 bucks. Let them know I sent you if you buy it thanks