I have a 95 Trans Am with 150k miles. The automatic trans was rebuilt 18k miles ago. It always shifted hard from 1st to 2nd, but it started shifting very smoothly for a day or so, now it wont shift to 2nd, but sometimes it will shift if i back off the throttle completley... whats goin on do I need another rebuild? how much is this going to cost me?

 

My 94 Z28 is doing the SAME EXACT THING well it was except now it finally just wont go up to 2nd, but anyways, mine was rebuilt not to long ago at all, 1K miles maybe, I did a lot of checking around at shops and i have the techtran manual for the 4l60E and i think it is most likely the 1-2 shift valve is stuck, do you have manual 2nd? as in putting it in the "2" position and starting out like that, the only forward gear mine has is 1st, well anyways im taking mine apart soon, lukily the 1-2 shift valve you can get to just by taking off the fluid pan. well if you find anything else out or if anyone could help us both out, its appreciated, thanks!

 

hey matto, i can put it in 1, 2, and 3, but it doesnt help, it still wont hit second gear unless I back off the gass completley... Third gear works fine though.

 

How does 4th gear work? It sounds like the 2-4 band is shot.

 

Hey, yeah im sure we both have the same problems with our trannys, anyways, im checking my 1-2 shift valve this weekend and maybe the servo assembly if the shift valve is OK, but it really really sounds just like it is stuck, on mine, and sticking on yours... well i will keep you posted and hopefully i can figure out whats wrong with mine and tell you, so you will save time and money, ill be back sunday or monday, have a good weekend. Anyone else have anything to add to this? please do

 

I have this problem too on a tranny that was supposedly built for racing. It has upgraded everything but I was out yesterday and I manually shifted when I left out of a redlight and then I noticed it was stuck in second gear. I can usually turn the car off and it will correct itself and work normally again. This tranny is about 2000-3000 miles old.

Here is the symptom when it is stuck in second. It will accellerate and when you let off the gas it will go back to idle. If you press the accellerator again it will rev back up to whereever it was last time you let off the gas if it is going the same speed. It is like it is mashing the clutch in when you let off the gas and revving back up to 3000-4000 rpm @ 45-50 mph to get it engaged again to accelerate more. Very very annoying, I just don't know what it is. I need to hook up my laptop to see if the computer it commanding it to change gears. It could be that the PCM is dying on me, I have went through a couple through bad flashes,etc... while programming it.

Hey GMTech, I have been looking for someone like you with experience with LT1's for a while to fix this car. I am over in Duluth, I am not sure how far from you but this car has caused me major problems like the one above. It has been modified by several diff people who somewhat know what their doing and now I don't have a very drivable car.

 

Hey, i never got a chance to check my 1-2 shift valve this weekend, ill be doing that next weekend. i was looking at how im taking the tranny off if i have to, how do i get to the top two bolts holding the tranny to the engine??? i didnt really look it over very well but i couldnt see them. they just seemed hard to get to, thanks, anyone else have anything to add to our 1st gear only problem? please do so!