This seal fits at the output of the rear axle housing, where it prevents lubricant from leaking past the rotating shaft and keeps contaminants from entering the differential cavity. It sits between the axle hub and the housing bore, maintaining a pressurized oil film on the shaft surface. A worn seal allows gear oil to weep onto the brake assembly or tire, reducing braking effectiveness and requiring fluid top-ups. The seal lip is designed to match the original shaft finish and housing bore geometry, so no adapter or shim is needed for installation. On reinstall, inspect the shaft surface for grooves and lubricate the seal lip before driving it into the bore.