If your differential is leaking gear oil at the pinion, this component may need replacement. The PORC Off Road Products pinion oil seal is designed as a direct replacement for Jeep models equipped with Dana 35 rear differentials. This seal installs at the pinion yoke to retain gear oil within the differential assembly. Manufactured with a steel outer shell and rubber sealing surface, it is built to match factory fitment and function. Replaces OE reference 83504946 and interchange part number 16521.10.