The allowable total eccentricity is the maximum total eccentricity at which the sealing edge can accommodate shaft rotation and retain adequate sealing performance. The oil seal's allowable total eccentricity is affected by the design of the oil seal, the accuracy of the shaft, and the operating conditions.
Figure 2: Typically shaped oil seal and component nomenclature
Refit the rocker or cam cover, aligning its fixing holes with those on the head. Check that the gasket edge aligns with the cover flange all round, and is not distorted. If necessary, adjust it gently with tweezers or long-nosed pliers. Tighten bolts evenly to just compress the gasket.
Figure 4.6. Rubber reinforced with carbon black and CNT nanocomposite to reduce the accumulation of heat in tyre [42].
For installation tools, make sure that they do not have any jagged edges that may damage the seal during the installation process.


As shown in Figure 1, sealing devices come in two types: contact and non-contact.
Oil seals are among the major contact type sealing devices.