Oil seals come in various shapes to fit the machines and substances to be sealed.
Figure 2 shows the structure and the names of the various components of the most typical oil seal.
The functions of the various components are also indicated in Table 1.
The garter spring is located at the end of the primary sealing lip and used to apply pressure to the sealing lip against the shaft. Common garter spring material types are:

Rotary Wheel Of Auto Parts
Selecting Quality Gaskets and Spark Plugs

VMQ, also known as silicone, is also used for oil seals, but this is less common because the mechanical strength of VMQ is low and this material has poor wear-resistance This makes it less suitable for dynamic applications, but it can withstand fairly low and high temperatures from -60 °C to 200 °C. Many types of VMQ are also suitable for contact with pharmaceutical and food products, so VMQ is an option worth considering. VMQ oil seals are usually available on request.
When the bore and shaft centers are misaligned, seal life will be shortened because the wear will be concentrated on one side of the sealing lip.

Remove the key and keep it safe until ready to refit the pulley.
Oil seal installation
New spark plugs are integral to the efficient operation of the engine, playing a critical role in igniting the air-fuel mixture within the combustion chambers. Over time, spark plugs can become worn or fouled, leading to decreased engine performance, rough idling, and reduced fuel efficiency. Replacing old spark plugs with new ones is essential for maintaining optimal engine performance, fuel economy, and emissions control. High-quality new spark plugs contribute to reliable ignition, smooth engine operation, and reduced environmental impact.
Oil seals go by many names, such as shaft seals, dirt seals, grease seals, lip seals, and many other variations of these. They are essentially simple devices used in rotary shaft equipment to prevent lubricant from escaping and for excluding contaminants such as dust, dirt and water. An oil seal’s most important function, however, is that it protects every type of ball, sleeve and roller bearing in the rotating shafts. The seals also prevent the integration of two different fluids that shouldn’t mix, such as oil and water.
The spark plug is essentially a device that generates an electric spark to ignite the compressed air-fuel mixture inside the engine cylinder. This ignition process creates a small explosion, which pushes the piston down and ultimately drives the vehicle forward. Without spark plugs, the engine would not be able to start or run efficiently.
Leather is probably the oldest of the lip materials still in common use, but the move towards mass production methods has seen a massive increase in the development of synthetic rubbers which lend themselves to accurate and repeatable injection and compression moulding. Nitrile (NBR) is still by far the most common elastomer for “normal” use, whilst Viton® (FKM/FPM) is rapidly replacing Polyacrylate (ACM) and Silicone (VMQ) for high-temperature applications. Viton® also has high resistance to abrasion and chemical attack making it a preferred elastomer. Recent developments in the use of PTFE for Rotary shaft seals has caused widespread interest particularly for high-speed shaft rotation or poor lubrication applications.