The 4L60E in my 95 is only a year old. It was shifting great with my stock motor that through a rod in October. I finally got the new motor in last week. Ever since then the tranny slips when its goin into 2nd at part throttle shifts and bounces on the rev limiter for a second at WOT. Once it finally shifts into 2nd, it holds fine.

What controls the shift into 2nd that could cause that?

 

TTT. Still having the problem. I've noticed that if I let off the gas for a second after 1st gear it wil shift easily. The trans still holds fine once it goes into 2nd.

Could it be one of the shift solenoids going bad? Or maybe in the PCM programming?

 

After doing a little research, I think it might be the A or B shift solenoids. I think I'm gonna try replacing those unless somebody will help me out with another idea.

 

Have Datamaster? Scan for PCM and transmission trouble codes.

 

The Service Engine light hasn't ever came on with this problem. That should mean there are no codes to check.

 

I still haven't done the shift solenoids yet, but I have replaced the TPS and checked the VSS. I also downloaded datamaster. No trouble codes that I could find and the PCM is commanding the shift into 2nd.

I have also figured out that the trans isn't going in to 2nd at all. It will skip 2nd sometimes and go straight to 3rd. If I manually shift, it will act like a neutral instead of 2nd.

 

This being tha case, Your issue is not with the solenoids but some issue with either the 2-4 band or the second gear servo .

 

If it was the 2-4 band, wouldn't I be having problems with 4th gear too?

The secend gear servo has crossed my mind as a potential problem.

 

I have seen where the band can be badly burned and hold in 4th since theres generally little load. but i would check the servo and the 1-2 accumulator.

 

Would the 1-2 accumulator have any effect on downshifting from 3-2? Cause it won't do that either. It acts like it's going into neutral. It's like 2nd gear doesn't exist.

 

Yes it could as could the servo and band I would take one step at a time check the servo then the accum and last the band