Ok so what could be my problem ??? Here's the situation : If the gear selector is in D or 3 nothing happens, but if I put the selector in 2 or 1 then I have manual 2nd or 1st. This is in a '99 GMC Sierra w/ a Transgo that was already installed before the rebuild and everything worked fine. New shift solenoids were installed, could this be my problem or the shift switch on the side of the tranny ??? Seems like something electrical to me...Zed

 

ok i know this is a dumb question but is the trans properly filled. If its low on fluid the trans usually works if you put it in 1st or second but wont work in 3rd. It may have seemed full when you filled it but if you dont move the gear selector through all the gears to fill all the channels than it willbe high untill you do. Once you move the shifter the fluid will fill all the passages in the valve body and than your fluid will be too low and drive wont work... Check the fluid with the car running and up to temp.

 

if i had to take a guess at this i'd say you have a broken forward sprag. i've ran into that same problem before.

 

Cool, I wanted a second opinion. We replaced the front sprag and we think we put it in backwards. So I guess it's time to tear back into it to put it the right way. Thanks Zippy I really owe ya one.

 

no problem. i've never installed one backward myself, but i have heard of it happening. from what i understand it works just as good backward as it does if it's broken. at least you have a good target on fixing it. problems after a full rebuild can be confusing for sure.