I recently bought a 2000 wrangler 4 cylinder knowing that it had a differential problem. Sure enough when I took the differential cover off I could see two teeth off the worm gear laying there. After separating the spider gears and etc. I ordered the 4.11 ratio worm and ring gear for it as well as new bearings for it thinking that was what caused it. When I pulled the rear axles out I later noticed that on the passenger side the axle bearing had rubbed the hell out of the axle right before the studs. The other side is fine, but I cant figure out why it's doing it to the passenger side. I ordered a new passenger side axle and bearing hoping that all will be well, but when I called the previous owner he said they also put a new passenger side rear axle on due to the same problem. So I have no doubt it will do it to the new one. I dont really want to put on a new one if it's going to do the same thing, is there any underlying problem that could cause this?