I just spent over $1,000 having the pinion bearing replaced on a 2002 Jeep Wrangler that barely has over 55,000 miles on it. It is a 6cyl auto. I also have a 99 Jeep Wrangler that has about 67,000 miles on it, 4cyl, 5speed that I haven't had this problem. Does this sort of thing happen a lot on automatic transmission Jeeps? Just curious.