5r55E loses reverse after warming up

[Drabix]

Everything shifts fine cold. About a mile down the road, I develop a bad flare on the 2-3 shift and then reverse will quit working. Let it cool down an hour or two and reverse is back. Anyone have any ideas?

 

[drdoom]

Wild guess

...valve body gasket.

 

[Drabix]

Repalced valve body, seperator plate, and low-reverse gaskets, torqued everything to spec and the problem is gone.

Thanks for pointing me in the right direction.