I just had a trans rebuilt on a 95 Trans Am, It shifts good through 1,2,3 but lags going into overdrive. My tranny guy hooked up is equipment and said that the pressures are all good up till it goes to shift the looses pressure. He replaced a solenoid that controls that shift but didnt make a differnce either. I dont know all the exact details cause its been a week since he told me everthing but he said everthing in the tranny is good and thinks its either in the PCM or in the wiring. So I got another know good PCM and swaped it out same problem. So I am assuming its in the wiring or there is in fact is a problem with the Tranny. I have another 4l60e tranny i can put in there but I dont want to do that if it is infact something in the wiring.

So has any one else had any other problems like this and can give me some advice on what to look for?

Thanks for any suggestions
Christopher

 

Ok so i never drove the car my buddy did and he completly described the problem wrong, The line pressure is all over the place while driving the pressure bounces from 50 to 225 psi. the tranny shifts ok when your not in the throttle but as soon as you get into it it doesnt shift right cause the line pressure isnt there like it should be. my tranny guy has already replaced the epc solenoid and was thinking it was a problem with the PCM because the epc solenoid is not getting the right signal for proper pressure. So i guess it somewhere in the wiring we are going to dig into this weekend

 

Get a trans go part #46-mod.It gets rid of the epc and uses a modulator for line pressure. It will stabalize pressure across the board.