Jimmy reverse (auto transmission) will not work. It just rolls when put in reverse. Jimmy does drive forward. Transmission bad or rear axle?

This sounds like a tranny problem. Check your fluid level just to be sure, and check its condition, ie. burnt or not.

big problem with these transmissions. You lost Reverse 2nd and 4th I bet. The drive shell breaks to do design flaw. So I'm sorry to say its time for a overhaul unless you find a shop to just put a shell in but I don't recommend it.

It happened to mine also, lost 2nd 4th and reverse. G. M. Dealer replaced for $2500 with 3 yr and 50k mile warrenty