Before fitting the oil seal, it is essential to check that the oil seal, shaft and bore are clean and undamaged. The surfaces the oil seal will come into contact with must be free of sharp points or burrs. The sealing lip is fragile, so even minimal damage can cause a leak. It is also important that the shaft and bore are correctly finished.
1. The oil seal consists of a metal ring as the inner skeleton which provides the structural stability to the oil seal.
Preparing to replace the sump gasket


Oil seal performance is affected by not only the type and material of the selected oil seal, but also a variety of other factors, such as operating conditions, total eccentricity, rotational speed, the substance to be sealed, and lubrication conditions.
Figure 9 shows items relating to oil seal characteristics.
The pulley is kept from turning on the crankshaft by a key fitting into grooves on the crankshaft and pulley.

If the shaft or housing gets damaged, it must be repaired. If you replace only the oil seal, but the shaft or bore remain damaged, then there is a chance of premature failure or leakage. You can easily repair the shaft, for example using an SKF Speedi-Sleeve.