Seals (Lip-Type)

Generally the toe or spring-loaded lip of an oil seal faces the oil being sealed or the oil having the higher pressure. The toe or lip of a grease seal faces away from the lubricant being sealed. Unless otherwise specified, use the preceding rules for installing lip-type seals.

The main parts of a lip-type seal are the case, sealing element, and the garter spring. The illustration shows the construction of a simple lip-type seal. The cross section shows the terms "heel" and "toe" used to identify the sides of various types of seals.

Lubricate the lips of lip-type seals before installation. Use the same type of lubricant which the seal will be operating. Do Not use grease on any seal except a grease seal.

If during installation, the seal lip must pass over a shaft that has splines, a keyway, rough surface or a sharp edge, the lip can easily be damaged. Shim stock or other such material can be formed around the area to provide a smooth surface over which to slide the seal.