I need some help here, I just had a 3200 stall put in and now my trans 4l60e does not want to shift at WOT at 3/4 it shifts perfect. I had a computer tune done twice and even rewrote the entire file and the shift pattern stays the same. I had the trans looked at and they said the trans is fine no problems. The trans only has 46k on it and I have never had any problems. Can someone help shed some light on my problem?

 

right before it is supposed to shift, put it in neutral and floor it, then bring it back down to manual 3rd

 

Sounds like you still have a tuning problem IMO now I am not a tuner so I cannot tell you what it is. But thats where its points

 

Its a tunning problem. If you change the stall you have to retune the tranny and check the shift points.