91 Camry transmission shift

rough
camry
transmissions

#1

I have a '91 Camry that's my daily 50 mile round trip commute car. It runs well and still has lots of pep at 156,000. There are oil and tranny leaks (tranny leaks around the pan seal) but I check the levels and keep everything topped off. Tranny fluid and filter were changed about 20K miles ago. I am the original owner.

Shifting is OK unless I accelerate hard, then it "bumps" into gear. On hard acceleration it is a pretty good bump but if I back off the gas it shifts much better. There are no other symptoms, at lower speeds it shifts fine unless the A/C is on, then I get bumps above the 1-2 shift.

Any ideas on what the problem is?


#2

Personally I would recommend not accelerating so hard. When was the last time you changed the transmission fluid and clean/replace the filter?


#3

As I posted, changed fluid and filter about 20K miles ago.

The hard acceleration is when I get onto the expressway. I'm not saying it's floored, just more than pulling away from a stop sign. If the A/C is on, it even shifts hard then.

I've read about later models having an accumlator that acts like the old modulators on GM vehicles. Didn't know if there was an accumlator on the 91 Camry and where it is.


#4

This transmission is electronically controlled (ECT). If I select the "normal" setting it shifts sooner and there isn't as much hard shift between 1-2, 3-4. If I select the "power" setting it doesn't change gears as easily unless I let off the gas, then it shifts without any bang. I rarely use full acceleration but if I do and don't let of the gas, it will shift but it's a hard shift. Even at moderate acceleration there is a bump if I don't let off the gas.

Aside from the hard shift, when I first get on the expressway with moderate acceleration the shifting is very odd. It's not a hard shift, sometimes a really smooth one, like when it would normally go into overdrive.

Is there a module somewhere that controls the shifting and is there any way to test it?