Kartboy Rear Diff Crossmember Bushes HardRear Diff Bushings Race Ever shift super fast and hear a clunk from the rear of your whip? Yeah? Thats because the rear differential is moving around on squishy bushings. Stop the movement madness with our harder bushings. These sandwich the rear sub frame outriggers, and eliminate some of the squishiness. These are the super hard race version for those of you that dont believe in compromise. NVH will increase, but who cares, right? Racecar!