I fought that for two years. I started putting the spare tire inside when offroading because it was so infuriating. I tried everything, adding rivets to the outer skin and the inside supports and wedges in any internal gaps between inside supports and exterior skin. I adjusted my latches many times. Nothing seemed to work. Then I hit upon the solution. I added a additional rubber spacer to the bottom of the tire. The back door has two rubber spacers at top of the back door for the tire. I used a extra rubber spacer that I got from a junkyard. I put it in the 6 O'clock position with a sheet metal screw. That fixed it and I have been offroading for years without a problem. I even now carry a 31x10.5x15 tire on a moddified stock mount and it works even with that heavy tire.