92 Lumina downshift problem THM440-T4

[nim]

Help! My 92 Lumina 3.1 4-speed transaxle THM440-T4 ME9 intermittently downshifts to neutral (instead of 1st) upon braking to near or complete stop. I have to manually shift to 1st gear and then I am "in gear" and can shift back to drive or overdrive. What is the likely cause of this problem? No one I talk to has a clue. Really strange is that it began to appear almost three years ago and would occur a few times within a week and then disappear for six months. Finally it occurs several times a day now and seems to be worsening by the day. More clues that might mean something: In the beginning, it would downshift on its own, but would take 3-4 seconds of sitting at a complete stop. Back then I could encourage it to shift by tapping the accelerator gently. When problem occurs now, even gentle reving of the engine won't shift to 1st. Sometimes shifting from overdrive to neutral and back to overdrive will cause it to shift, but lately that has failed to get it out of "neutral". It's requiring a manual shift to 1st instead. No other problems with transmission. Fluid level appears ok, fluid looks ok, no funny noises. Is there any hope it can be solved without a total replacement or rebuild? Thank you to all who offer comment.

[edwck]

Originally Posted by nim

Help! My 92 Lumina 3.1 4-speed transaxle THM440-T4 ME9 intermittently downshifts to neutral (instead of 1st) upon braking to near or complete stop. I have to manually shift to 1st gear and then I am "in gear" and can shift back to drive or overdrive. What is the likely cause of this problem? No one I talk to has a clue. Really strange is that it began to appear almost three years ago and would occur a few times within a week and then disappear for six months. Finally it occurs several times a day now and seems to be worsening by the day. More clues that might mean something: In the beginning, it would downshift on its own, but would take 3-4 seconds of sitting at a complete stop. Back then I could encourage it to shift by tapping the accelerator gently. When problem occurs now, even gentle reving of the engine won't shift to 1st. Sometimes shifting from overdrive to neutral and back to overdrive will cause it to shift, but lately that has failed to get it out of "neutral". It's requiring a manual shift to 1st instead. No other problems with transmission. Fluid level appears ok, fluid looks ok, no funny noises. Is there any hope it can be solved without a total replacement or rebuild? Thank you to all who offer comment.

Interesting... as I too own a 92 Chevy Lumina Eurosport 3.1, 4-speed transaxle THM440-T4 with the same exact problems that you are experiencing. also my THM440-T4 transmission was leaking transmission fluid at the rate of approx 1 quart of per month (appears to be leaking from the front side of the pan) I left my car at a local Transmission repair shop today and instructed them to replace the following parts, the filter/screen/gasket, vacum modulator valve which controls the feel of the shift, and inspect/adjust the tv cable which controls the shift points.
I will let you know if any of the repairs did any good.

[maxwedge]

Originally Posted by nim

Help! My 92 Lumina 3.1 4-speed transaxle THM440-T4 ME9 intermittently downshifts to neutral (instead of 1st) upon braking to near or complete stop. I have to manually shift to 1st gear and then I am "in gear" and can shift back to drive or overdrive. What is the likely cause of this problem? No one I talk to has a clue. Really strange is that it began to appear almost three years ago and would occur a few times within a week and then disappear for six months. Finally it occurs several times a day now and seems to be worsening by the day. More clues that might mean something: In the beginning, it would downshift on its own, but would take 3-4 seconds of sitting at a complete stop. Back then I could encourage it to shift by tapping the accelerator gently. When problem occurs now, even gentle reving of the engine won't shift to 1st. Sometimes shifting from overdrive to neutral and back to overdrive will cause it to shift, but lately that has failed to get it out of "neutral". It's requiring a manual shift to 1st instead. No other problems with transmission. Fluid level appears ok, fluid looks ok, no funny noises. Is there any hope it can be solved without a total replacement or rebuild? Thank you to all who offer comment.

Make sure the trans pan is not dented giving you false fliud level readings.

[boscom17]

Did replacing those things fix your problem edwck? I'm currently having the same problem.