Ok just rebuilt 4L80E good line presure, 14 quarts in it, Start vehicle, Place in gear fwd or rev and feel distinct bump as if it went into gear, But while will move wheels on lift does nothing on the ground, Pans clean nothing out of oridinary. Does have the transgo presure releif but looks to be working properly.
"New converter" stock type from monster transmssions.
My thought is sprag in converter ? Anyone else ?
My reasoning it has line. FWD / REV separate hydraulic circuits yet same result in ether position . Pumps workng and presures good, Short of two completey different failures for rev and fwd . I cannot think of anything else that could create such a situation .

 

Initial thoughts in this situation would be the TC.

 

I agree, it would seem to have to have two different issues in order for fwd and rev not to work. That only leaves the TC.

 

Does it move in D3?

If so...OD roller clutch

Either mis-installed or mismatch year.

Tq converter sprag could be missing entirely and the thing would still move. Just wouldn't perform well...but it would move

 

he says it bumps into gear FWD and Reverse but wont actually move on the ground in any gear d 1 2 3 4 or rev. Now in the air it will turn the wheels he said. I am helping remotley do exactly all it will do on lift I do not know.

Kinda baffling really/ But indeed many years ago I did have a TH350 do this and whatever it was it was in the converter which was a reman , Tore unit down was perfect i every way . replaced converter and off it went. It to infact would bump pretty firm when moved to rev or fwd just would not actually move.

He has bidirectional controls I told him to try commanded second and full lock up and see what happens. Waiting to hear back .

 

Ok Have answer, Seems drive shaft goes but car does not . so guess that is the answer. Which is strange as he said its a brand new complete axle assemby but the drive shaft spins away but the wheels dont go .

 

Well that's good at least.

Maybe the Pinion Gear failed...