Bolt Savers 3 protects the rear bolt from bending and the oem bushing rubber from excess side to side movement and wear.
Bolt Saver Plus protects its bolts and protects the differential and rear oem bushing from forward and backward movement and ware.
Both bushing help protect the driveshaft spline adhesive from failure due to dynamic drivetrain movement. All of the Bolt Saver Kits add zero NVH.