Storage and Handling
Oil seals, also referred to as shaft seals, are widely used to prevent the leakage of medium (such as oils and grease) along a rotating shaft. This leak prevention is primarily achieved by the sealing element which can be made from a wide range of materials that are chosen according to each application. They are commonly used in gearboxes, hydraulic cylinders, and related components.
There are several key factors to consider when selecting the right oil seal to best protect your application.

Smear clean engine oil on the pulley sleeve and seal, then refit the pulley with the key and keyway aligned. Tighten the bolt to the correct torque (consult a service manual or a dealer if in doubt).
In order for the sealing property of the oil seal you selected to really shine, attention needs to be paid to how it is handled.
In the event of seal failure, it is necessary to take effective countermeasures.
: prevents particles from reaching the sealing lip.
On most cars you need to remove several parts to get at the seal.