Ok so my Fraternity has a 1992 GMC short bus. the trans has a 17 bolt pan so im going to guess that its a 4L80E. i know for a fact that the trans has been rebuilt and no one is sure that it is even the original trans. from what ive been told is that originally it lost OD then only had 1st and 2nd gears. and now it only has 1st and reverse. on the sime of the trans case it says Hydra-matic 8680581 4. I didnt know if this was a id # or Casting # of some kind. i am an auto tech student but i dont know anything about automatic trans or diesels, i know manual trans and gas engines lol. would just a rebuild fix this or could it be a computer problem?

i took the trans out and the fluid looks and smells fine. and the pan is fairly clean. once i find my camera ill put up some pictures of it