Helping a friend on a 51 ford sedan. 429 C6. Transmission has been built. Problem is, got it in car hooked up drive shaft. Car will roll forward in neutral but won't roll back. The guy that built the tranny said he checked it when he finished and it would turn both ways. Any suggestions? Thanks, Steve

 

Is this with engine running or with engine off?

 

We have just gotten the engine and trans in the car. It is not running yet. I've still got to wire the car. Thanks, Steve

 

I had a few ideas had it been with the engine running. With engine off the only thing I can think of is that the parking pawl is not fully retracting when it is shifted out of Park.
maybe disconnect the driveshaft at the axle and try turning it by hand (after shifting out of park a few times), make sure it turns in the forward direction and then try turning it in reverse and see if you can feel what is happening.

 

We've got the trans out now. Freely spins one way won't turn at all the other. Will try again by shifting and turning. Thanks, Steve

 

is the torque converter still on the trans while u have tried it since it has been out? when i did mine, the input shaft would turn fineand the yolk would only turn one way. when i put the converter on it wouldnt spin. come 2 find out that when u assemle the pump assembly, its best to put it together on the torque converter itself. after doing this, it turned fine in one direction and kinda stiff in the other. but once it was in the truck, it works just fine now.

 

Thanks for the replies. We do not have the tc in it right now. Something is locking it up really hard one way. We thought the ban might be too tight but that wasn't it. They are working on it now. I had to leave. Will update later.

 

Found the problem. Band must not have been adjusted properly when it was built. Had popped out of place and was binding it up one way. Thanks for all the replies. Steve