For carrying the oversize tires, the WARN Rock Crawler rear bumpers are designed to accept a WARN Tire Carrier. Built to carry heavier tires (up to 37"), the tire carrier pivots on a beefy 1-1/2" solid steel shaft pin, which comes up from within the bumper into the frame of the tire carrier. The shaft itself is welded, not bolted. Structural t-joint welds (vs. corner welds) mean the bumper holds up in the long run. A polyurethane pad reduces rattling with frame reinforcing brackets. Bumper sold separately.