92 Toyota Corolla DX automatic transmission slipping/no shift

[mycarr]

I have a 92 Toyota Corolla DX, 1.6Ltr transaxle with 3 speed automatic transmission. There is an intermittent problem with the transmission that does not happen all the time. It usually happens at about 45MPH going up a slight hill or a steeper hill it shifts from 3rd to 2nd as it should, but instead of going into 2nd the transmission slips and transmits no power as if it was in neutral. When this happens the only thing I can do is slow down an manually shift to 1st, then the only gear that works is 1st, if I manually shift to 2nd or drive it just slips like it's in neutral. If I stop the car and put it in park then the transmission usually works properly again. The transmission fluid looked good and was at the correct level. I have had the car in the shop for transmission flush, but the problem remains. Can anyone tell me what the problem is?? thanks

[jdmccright]

Any check engine light or "O/D OFF" trouble light shown on the gauges? My guess is a faulty shift valve. Check for stored codes and post back your findings.

[mycarr]

No trouble lights of any kind. All codes are normal.

[jdmccright]

Please verify...you are able to upshift from 1st to 2nd and continue accelerating to 3rd, but when you slow down, the downshift from 3rd to 2nd results in slippage?

[mycarr]

Originally Posted by jdmccright

Please verify...you are able to upshift from 1st to 2nd and continue accelerating to 3rd, but when you slow down, the downshift from 3rd to 2nd results in slippage?

Correct, when car slows from a hill the downshift from 3rd to 2nd results in slippage, like as if its in neutral. But this happens only once in a while, not every time.

[jdmccright]

While I don't have your exact transmission model, it sounds like you are having problems with the low modulator valve (an on-vehicle repair) or the B(1) second coast brake (an off-vehicle repair). What sounds like is happening is you are not getting the engine braking feature which is the typical reason for driving in either the "1" or "2" gear shift positions, typically to help slow the car coming down steep hills or slippery conditions.

Does the condition happen when you drive with the gear selector in "2"? The engine rpms should stay high as the car slows down, not drop to idle. If it is intermittent as you mentioned, I'd be more suspicious of the sticking valve versus the brake.

In either case, there's little reason to tear into the tranny with that many miles to fix one thing. You might as well have the valve body or the whole tranny rebuilt to avoid having something else break shortly down the road...you typically get a warranty on the work as well. Valve body work is somewhat less expensive as it can be removed separately while leaving the transmission installed. Hope this helps!