I was offroading today. I had it in 4HI w/o lockers on. All of the sudden I heard a CRACK and it started grinding like no other. It only did it in gear. The car would not move anymore. I locked the center diff and drove it home fine though. (In 2 wheel drive I assume). I know nothing about these drivetrains. My dad thinks its the transfer case What happened? Can I buy a rebuild kit for this problem? Any help would be appreciated.