2002 Alero Transmission Jerks when upshifting/shifting between gears

[sarotara]

2002 Alero with 3.4L engine and 93k miles
- This is an ongoing problem that got significantly worse today. There is a jerking forward feeling while the car is upshifting during normal driving. No engine trouble codes. Parked the car, revved the engine to make sure that the engine mounts weren't broken. They are not. However, with foot on brake pedal and shifting between gears with hood open, you can feel and see the whole engine jerking. I'm assuming that transmission mount(s) are broken. Are these difficult to replace? Does anyone have replacement instructions including torques? Would be highly appreciated.

[BNaylor]

Best thing to do is visually inspect the engine mounts. Also, make sure they are tight on the subframe assembly. There should be 3 to look at. Front of engine, passenger side and the one in the back. If the rear one is bad you may also get alot of vibration going into the cabin.

Have you checked transaxle fluid level?

[sarotara]

I thought this would be a problem specific to the transmission mount only, no? What is also odd about this is that while this issue is recurring, it doesn't always happen. Sometimes it's pretty bad, but sometimes the shift/buckle in upshifts/gear changes disappears. Don't know what to think of it...


The transmission fluid level is fine... but I would like to find the person that left out the transmission fluid level dipstick on these models.

[sightdev]

Originally Posted by sarotara

I thought this would be a problem specific to the transmission mount only, no? What is also odd about this is that while this issue is recurring, it doesn't always happen. Sometimes it's pretty bad, but sometimes the shift/buckle in upshifts/gear changes disappears. Don't know what to think of it...


The transmission fluid level is fine... but I would like to find the person that left out the transmission fluid level dipstick on these models.

it may not have anything to do with trans or any of the mounts. from what you are describing, it can simple as clogged up fuel injector(s) or other mechanical problem. since this is occuring "sometimes" during upshift may be cause by dirty injector causing minor misfire. I am assuming your plugs/wires/coil have all be checked good and you already did your 100k maintenance? if you have done the usual 100k maintenance, pour in a good quality injector cleaner in your gas tank to see if it improves. I put one techtron intake treatment every 10k during oil change.

[kydrifter]

My 2001 had this issue and the trans seemed to slip on long hills and at times it seemed like you would turn the key off and back on, After another Trans and numerous sensors and parts a guy in the other end of my state told me to replace the Throttle Position Sensor. Wish I would have talked to him sooner, It fixed my problem and could have save me a lot of Money.

[Tech II]

Was the vehicle checked for tranny codes?

[kydrifter]

Originally Posted by Tech II

Was the vehicle checked for tranny codes?

Did not have checked for trans codes, had no engine codes and no engine warning lights on

[Tech II]

Not all tranny codes turn on the CE light....in some cases it has to fail on two consecutive trips, to turn it on....in some cases where a code is set, but the light is not turned on, the PCM may command FULL LINE PRESSURE .....THIS WILL CAUSE HARSH SHIFTS IN THE VEHICLE.....