i have a 4l60e that only had 1st gear and reverse. if it shifted into 2nd then it made crunching sounds and would lock up completely. now i tore it apart today and found the lo and reverse roller in the back of the tranny was shattered in a few places and the roller was in pieces.
i replaced that and added a shift kit while i was in there. there is no crunching sound , but its still got no movement in 3rd or d. but if i drop it down to 1st or 2nd it catches. the only thing i could think of is maybe there is some debri blocking a passage somewhere. any advice would be greatly appreciated

 

well, i took it for a spin today after the repair and i have to manually shift it from 2nd to third and there is no fourth at all?!!! i dont get it . what could be the culprit?

 

ok now i got up to speed and shifted 3rd -4th and it revved up then suddenly shifted.ever since that it seems to be shifting right...should i still be worried about this?!?

 

I recently tried to install a bm kit in my tranny --failed, then had to have the whole thing rebuilt and the shop had to reinstall the kit. But when I first put the kit in I couldnt locate the pressure reg valve and started pulling valve assemblies one at a time till i was to find a assembly that looked like the picture in the instructions. When I got to the 4th gear vavles, i pushed it in to relieve the snap ring and the assembly shot out before i could see how it went in. Could not put it back in correctly. So I had no 4th along with other problems that lead to the death of the tranny. I dont know if you dove into the valve body and my problem maybe irrelevant to yours but it is just food for thought.
Does it over rev everytime you go from 3rd to 4th? Do you have to do it manually? Does it shift right ALL the time now or does it still goof up now and then? sorry for the lenghty letter.

 

Sounds to me like you have a foward sprag problem