auto trans downshifting problems... - Toyota Nation Forum : Toyota Car and Truck Forums

barthmonster · 08-29-2010, 08:11 AM

My 91 Corolla runs good but doesn't downshift like it should I have to click it down manually...

Now admitting that I'm behind on maintenance I know I need to service the trans first and foremost. But after that, then what I'm about 50 %sure the cable is involved. How do I adjust the cable ??? Is shifting it manually all the time bad for it ?? (wow I need to convert this thing to manual but I'm still looking for parts and I'm cheep !!)

Thanks in advance guys I really appreciate all the help here. I did a search but there was pages and pages with no downshifting problems...

Do these have a vacuum modulator like American cars ?

Donald · 08-30-2010, 12:14 PM

If you are going to do your own maintenance, I recommend you get yourself a manual. The Toyota manual is best and worth it in my opinion, but at the very least a Haynes manual will help you get to know your car.

To adjust the "kick-down" (throttle valve) cable, have someone step on the gas pedal, all the way to the floor.
Make sure the throttle plate is all the way open.
The kick-down cable has a little slug crimped to it, and this slug should just stick out of the black rubber tube at the end of the cable sheath.
Adjust the cable sheath jamb nuts to get the slug right at the end of the rubber tube. That's it.

If it still won't kick-down, and your fluid level is correct, I suspect your tranny is on it's way south.
Try using Lucas transmission treatment. Drain and refill uising one quart of the lucas mixed with one quart of regular transmission fluid.

I have personally used it, and believe it extended the usefull life of failing transmissions. It reduced slippage and improved shifting. Mind you there is a limit to what it can do.

Good luck.

barthmonster · 08-30-2010, 12:29 PM

Thank you. I have the Haynes but didn't think to look yet. I see it's there.

As I said I'm sure it needs serviced too but I'm glad you mentioned the Lucas transmission treatment. The car and trans have 166,000 miles but the engine is new and strong, so I don't want to take any chances with the trans.

I don't notice any slippage (over-revving) however it seems to have terrible mid-range (2nd gear ??) so possibly 2nd is engaging but 1st isn't dis-engaging properly. That might be slippage too I don't know...

The fluid-level is in fact a bit high. Will get corrected when I service it.

Donald · 08-30-2010, 01:02 PM

This is what you are looking for.

barthmonster · 08-30-2010, 01:38 PM

Thanks some more. That actually answers my own pondering 'Why do they always tell you to get a 2nd person to push on the gas pedal, when I can just operate the butterfly directly with my hand' ?? hahaha!! Even easier to see if the throttle-blades are open 100% while you're there !!

Oh well, better than no manual at all. I wonder how much the factory manual is... hmmm...

barthmonster · 08-31-2010, 07:25 AM

armed with my manual and the above picture I went out to adjust the cable correctly. It 'acts' like it's too long, so something in my trans is screwed-up. at first with WOT, the marker was down inside the rubber about 1". After adjusting as much as possible, it's still down in the rubber 1/2". Also when the throttle is released, there is about 1/2 " of kickdown cable hanging slack that can't seem to be pushed into the housing towards the tranny.

Also when driving, kickdown at any speed and any throttle-opening up to WOT isn't happening, it just grunts at low rpm... I'll query the trans-shop to see if the kickdown stuff (or spring) is easy to get to in the trans but otherwise my trans is kind of broke and this gives me even more incentive to budget in the 5-speed conversion I've been drooling over...

Oh well....

Donald · 08-31-2010, 02:47 PM

Quote:

Originally Posted by barthmonster

Thanks some more. That actually answers my own pondering 'Why do they always tell you to get a 2nd person to push on the gas pedal, when I can just operate the butterfly directly with my hand' ?? hahaha!! Even easier to see if the throttle-blades are open 100% while you're there !!

Oh well, better than no manual at all. I wonder how much the factory manual is... hmmm...

Factory manual can be as much as $60, depending on the year
Go to books4cars.com.
I think the book for the '91 costs more than the book for the '92.
Maybe because in 91 there was a GT-S also and none in 92, but it is the same information so don't worry about that, get the cheapest one.

The reason I say get someone else to press the pedal, is to make sure the throttle is opening all the way to the stop, If yiou open it by hand, you won't know if the accellerator cable is pulling it all the way, or needs to be adjusted.

Quote:

Originally Posted by barthmonster

armed with my manual and the above picture I went out to adjust the cable correctly. It 'acts' like it's too long, so something in my trans is screwed-up. at first with WOT, the marker was down inside the rubber about 1". After adjusting as much as possible, it's still down in the rubber 1/2". Also when the throttle is released, there is about 1/2 " of kickdown cable hanging slack that can't seem to be pushed into the housing towards the tranny.

Also when driving, kickdown at any speed and any throttle-opening up to WOT isn't happening, it just grunts at low rpm... I'll query the trans-shop to see if the kickdown stuff (or spring) is easy to get to in the trans but otherwise my trans is kind of broke and this gives me even more incentive to budget in the 5-speed conversion I've been drooling over...

Oh well....

Sounds like your kick dowh cable is broken, or slipped off valve inside the transmission.

If you pull on the cable with your fingers, you should feel a spring pulling it back, if not, it is broken or loose.

It is easy to get to when you take the tranny pan off.

To drive without that cable disconnected will cause premature wear in your tranny, so I suggest you take care of that as quickly as possible.

barthmonster · 09-17-2010, 11:19 AM

okay, my vacation is over and the pan is off. The cable does have a spring pulling it back. At the bottom end, it wraps around a smaller wheel just like on top and it is connected. What now, I guess I have the wrong cable on that trans...

I'll re-check everything and get the 'assistant' to make sure the throttle is actually opening all the way. I find it wierd to have so much slack in the kickdown cable at idle though (it droops)...

Thanks again.