First, you need to clean the
Differential housing in the solvent. Then, please clean and inspect the differential housing for the mounting bolt threads, the case cover bolt hole threads, the sealing surface for nicks or burrs, the drain plug hole threads, the axle seal area, the drive pinion seal area, the rear differential support bushing bore, front right side differential support bushing bore, Vent for operation and cracks in the housing. Finally, you should clean the oil passage between the mounting bolt threads and the drive pinion seal area in the axle-bearing bore.