ok i just finished putting my trans together and got it installed today. alittle info on the trans:
th400 full manual reverse valve body.
alto red eagle racing clutches
kolene steels
upgraded 32 element sprag
everything was set to the companies specs as far as modification to the internal hard parts for the trans brake.

i have reverse and 1st gear, when i shift into second the tires come to a hault as if i had put it in park. (thank god i was on a lift that wouldnt have been fun.

any have any ideas, im about to start diagnosing this thing tomorrow as far as line pressure, piston apply, etc...

 

My guess is the intermediate snap ring is not installed or the case lugs are blown out.

 

i installed the snap ring from a newer model 4l80e so i dont believe that could have come undone. as far as lugs are you referring to the lugs that hold the intermediate support to the case?

 

You are probably thinking of the spirolock on the back of the direct drum, I'm talking about the large snap ring that holds the intermediate pressure plate in the case.

If this is left off or the case lugs are blown out it will lock up in 2nd gear.

If you installed the int sprag backwards it would lock up in 3rd.

If by chance you have a early 400 reaction carrier with sprag for low, if you install it backwards, you get only reverse and it locks up in all forward gears.

I install a heavy duty snap ring in the case for the int pressure plate but the 4L80E snap ring gains you nothing here.

 

yea sorry i was referring to the spirolock on the back of the direct drum. the snap ring is installed on the intermediate support along witht he bolt under the valve body. the lugs didnt look blown out to me. there was no play in the intermediate support in the case.

i have first gear so i dont think my sprag is installed incorrectly.

 

The int sprag can be in backwards and you would still have 1st gear.

It would slip in 2nd, and it would lock up in 3rd.

 

The sprag can be in backwards and you would still have 1st.

 

It definately locks up in secon gear. As far as third It doesn't move either