Gotcha.
I just did a quick lap around the block before seeing your post.
It works fine (didn't check engine braking) in everything except reverse. It will back up but will shudder a little and slip if throttle is applied.

Rear band or front clutch?

Manual low works fine.

We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind.
- Stu Harmon