I think I've done the impossible - break an XR. I was running the Ironman last weekend and doing okay, but on the second lap I hit the big hillclimb and halfway up, the gearbox started banging loudly like it was hung between gears (I was in second at the base of the hill). I made it to the top and stopped to check it out and the only gears I could get the bike to go into were neutral and fourth. I limped across a corn field to the truck in fourth. I got it home and cleaned it real good (lots of mud from the race) and now it will only go into neutral and first - nothing else. Theres no shift lever to case interference and the oil is clean and at the right level. Thel clutch plates, springs, and cable have about 12 races on them and don't appear to be the problem. I'm going to do some exploratory surgery, but thought I would check here to see if anyone has any ideas of what I should look for. There are no abnormal sounds coming from the gearbox or anything, it just won't go into all of the gears. Any help would be appreciated. Thanks in advance.