The Effect of Environmentally Conditioned Gear Lubricants on Unitized Radial Lip Oil Seals

There have been persistent, unexplained unitized wheel seal leakers in commercial vehicles. These leakers occur regardless of seal design or manufacturer. A study of these leakers concludes that stressed EP gear lubricants in combination with water can cause excess wear of unitized seal components. This paper describes the investigation into seal leak causes, duplication of the phenomenon in the laboratory, and suggestions for remedial action.