I did a search about my intermittent reverse after a transgo install and pretty much came up with incorrectly installed pressure regulator valve assembly. What are some other symptoms? Here is what my car is doing(or not doing):
Intermittent reverse - I had it once or twice
Rolls backward in foward gears
Heavy slipping in all gears
Has a 1-2 shift when the rear is jacked
The fluid is filled to the proper level also. Do all signs point to the PR valve assembly? Seems like every transgo install needs a 2nd pan pull, just making sure I won't need a 3rd. Thanks for the help.

 

That was the only problem, found the assembly in the pan. It must not have instantly blown out as I did have reverse once or twice. Of course it all works AFTER I put a drain plug in.

 

I didn't do the drain plug until after the 3rd or 4th time the pan was down, LOL, it was nice to have for the 5th pan drop after the TCC valve went out.

That drain plug makes all the difference in the world, going from an ATF rain forest to having the fluid in a drain pan. . .

RBob.