hitman3378

I had A friend that does some A/T work help me rebuild the 4L60E in my 04 1500, with a TCI kit P/N 378906 and a Huges 22-20EL converter I was going to replace the silinoids and harness but ran out of time and money. I know I should have taken it to a pro, but he had done some TH-350's, TH-700R4's and at least one other 4L60E that I know of. All of them have been sucessfull, but mine. I just got it in and it seemed normal on stands, I put it in reverse and the wheels spun backward, D 3 2 1 the wheels spun fwd. when I got it on the ground I had nothing in reverse, drive and third seem like it is slipping (more as rpm increases) and first and second appear to be normal. I have read some great threads on here this eveing, but nothing with the same puzzle pieces missing. I believe if my friend Jr. that done the build was still with us, he would have been able to figure it out but he's not and I'm stumped. Could it be a electronic issue? Any help would great. I'm driving my 79 chevy mud truck and stoping at the gas station every other day to feed the 454 is breaking me!

1-87 chevy

iTrader: (15)

Sprag issue

mrvedit

If putting the shifter into [1] or [2] gives you forward motion, but not [3] or [D], then indeed the forward sprag is likely the problem. It is easy to put in upside down, or it is defective.
However (correct me if I am wrong), the forward sprag is not used for Reverse. I suspect this is a separate problem. Of the people I have helped here with "No Reverse" the most common problem is a bad/torn teflon ring on the stator shaft. This often occurs because no resizing tool was used during assembly.
It is not an electrical issue.
In summary, it appears you have two problems and the trans will have to be removed and rebuilt correctly.