Wheel end and oil bath seals are used to seal heavy vehicle wheels. Wheel end seals and oil bath seals prevent oil leakage from oil bath hubs and ensure that the wheel bearings stay lubricated, reducing the need to repack or replace wheel bearings. Vehicles equipped with oil bath hubs have caps on the axle that allow personnel to view the oil level. Any oil leakage indicates that the wheel end seal or oil bath seal needs to be replaced.