Well, finally got around to pulling primary off bike to find my leak. Got to looking at the trans and the seal was practically out and maybe just me, the gear looked further out than should be. Anyone ever have this happen? It is a early 86 with the keyed shaft. Do I have bigger problems? Havent taken tranny apart yet just got this far. Sorry no way to take pics camera is on vacation.

 

The main drive gear seats against the inside of the inner race of the big ball bearing. For the gear to be too far out, it would mean the bearing failed, or the bearing is not being held in the case.

Pull the big oil seal off and have a look.

 

Like Dan said the main bearing snap ring would of had to come unseated(loose) for the main drive gear to work it's way outward. If this is the case then the main drive gear would also be rubbing the case and making some racket. If the snap ring is still in place and the bearing race is in tact there is no way that gear moved.