The differential output seals are the seals located at the output shafts of a vehicle's differential. They usually seal the axle shafts against the differential and prevent fluid from leaking out of the differential as it operates.

Oil seals are used to protect shafts and bearings from ingress of dirt and foreign matter and egress of oil or grease. An oil seal generally consists of an outer circular metal part and an inner flexible member that does the actual sealing and is bonded to the metal part by chemical adhesive agents.