Rough Overdrive Shift

[redracer_13]

Hey everyone, been a while since I last posted. Since my last post I bought myself a 1996 Toyota Vienta Grande V6 Auto(Camry XLE Equivalent) with 75,000 miles. The transmission was just serviced about 1,300 miles ago

The only problem I've noticed since I purchased it is that it shifts really hard into overdrive when at lower revs. At higher revs it seems to shift a lot better. All other shifts seem fine. It was still shifting into overdrive poorly before the transmission was serviced.

I'm just wondering what are some of the things that could be causing this problem. Tomorrow, i'm going to attempt to adjust the kick down cable to see if that helps although i'm not expecting much improvement.

Other than that the car looks & runs like it was just driven off the showroom floor......

[JohnGD]

One of the things that absorb shift shock in an automatic transmission is the accumulator.

It basically is like a spring loaded piston in a chamber absorbing the ATF inrush. Maybe the o-ring seal is leaking?

I'm sure there are other reasons, such as like pressue, valve body issues. But don't lower the line pressure by overadjusting the cable outside of spec. have you ever dropped the pan to change out the strainer and clean the pan/magnets?

Here is an example of what an accumulator setup looks like:

Accumulator chamber, with spring and piston:
http://www.superchevy.com/technical/.../photo_06.html

Accumulator piston, spring and chamber:
http://www.gmhightechperformance.com.../photo_24.html

[redracer_13]

I myself have not dropped the pan but I watched as the mechanic cleaned the magnets and replaced the fluid... I'm not sure if he cleaned or replaced the strainer.

Well I may just compare the kick down cable against that of my other v6 Vienta just to make sure the previous owner hadn't played around with it before I bought it. And thankyou for the detailed reply. I've learnt to deal with it so if everything looks the same I might just leave it and next time let the mechanic have a detailed look.

[redracer_13]

Well after comparing the kick down cable to my other car I noticed my cable was way too loose so after tightening it up the problems been solved.

[fenixus]

could someone explain to me what a kick down cable is and where i can find it? i had transmission flushed at the shop a while ago, but still O/D shifting is a little rough especially when driving very slowly (e.g. traffic). i got used to it though. usually turn off O/D in slowly moving traffic for smoother driving up to someone else's bumper.

[redracer_13]

When looking at your engine locate the throttle cable......(If you cant find it get someone to press the accelerator with the engine off & you should see a wire that moves the throttle assembly or whatever its called near the rear of the engine) pretty much next to that is the kick down cable which looks similar to the throttle lead (I have the V6 so it's location may be slighly different to the 4cyl's location).

Here is the link that helped me to diagnose what my problem was...

Quicker Transmission Shifting

http://www.toyotanation.com/forum/sh...d.php?p=485045

All I did was tighten up the two bolts marginally so there was less slack on the cable...

[fenixus]

ah i see. thanks for the link, it also pictures it well. I think i will be messing with those cable quite soon

cheers

[fenixus]

done! thanks!

i seem to have less shifting in bumper to bumper traffic now and down-shifting on acceleration (highway) seems so much faster, i'm amazed! so simple and so great results

i left about 2-2.5 threads before top. works OK for me.

[drecan]

Originally Posted by redracer_13

When looking at your engine locate the throttle cable......(If you cant find it get someone to press the accelerator with the engine off & you should see a wire that moves the throttle assembly or whatever its called near the rear of the engine) pretty much next to that is the kick down cable which looks similar to the throttle lead (I have the V6 so it's location may be slighly different to the 4cyl's location).

Here is the link that helped me to diagnose what my problem was...

Quicker Transmission Shifting

http://www.toyotanation.com/forum/sh...d.php?p=485045

All I did was tighten up the two bolts marginally so there was less slack on the cable...

Holy cow, I adjusted it like 3mm and it fixed the rough o/d shifting and a vibrating while accelerating issue. Thanks for the post!

[fenixus]

drecan, remember that it may burn fuel faster now. the mod forces car to stay in higher RPMS while driving (will feel more sporty and responsive to accel pedal).

mod fixed OD shifting issue for me too, but than i returned the screw back where it was before bringing car for the tranny flush (66k). it came up that tranny after the flush started running like supposed to on its own without the mod.