Why is mechanical seal important in this situation? It is because the rotating shaft has to move in a wet environment, but there should not be the leakage of pressurized fluid. Hence, the role of a seal is quite critical.

When selecting spark plug wires and new spark plugs, it is essential to prioritize quality, compatibility, and performance specifications. High-quality spark plug wires should be designed to withstand high voltage and heat, ensuring reliable transmission of electrical current to the spark plugs. New spark plugs should be selected based on the specific requirements of the vehicle, including heat range, electrode design, and material composition, to ensure optimal ignition and engine performance.

Modern engine oils, such as the current SG classification for gasoline engines, contain a large fraction of additives, many of which are detrimental to fluoroelastomers. The primary functions of oil-additive packages are to protect metal parts, avoid deposits in the engine, minimize oil degradation, and adjust fluid viscosity. Little attention has been paid to avoiding damage to rubber seals. Instead, elastomer producers have been expected to provide new, higher-performing products at no increased cost to auto manufacturers. Among the additives with moieties that may attack fluoroelastomers at high temperature are detergents (phenolates), dispersants (succinimides, alkylphenol amines), and antioxidants (amines, sulfides, hindered phenols).⁴ Many of these components are multifunctional, containing phenol or amine groups that can dehydrofluorinate and crosslink VDF-containing fluoroelastomers, leading to loss of elongation and eventual embrittlement. However, the rate and extent of reactions with seals are affected by many factors, including whether air is present in the system. When oil is exposed to air at high temperature, additives may undergo considerable changes. For example, a significant fraction of amines may be oxidized to amides, which have little effect on fluoroelastomers.⁵

How are Oil Seals made?

Coat the sump flange with gasket-sealant and fit the flat parts of the gasket to it, ensuring that they are exactly positioned and joined.

Nitrile rubber offers good durability for general use, while the flexibility of the spring behind the sealing lip keeps the oil seal firmly in place against the moving part.

It is quite common for a groove to develop at the sealing lip at some point due to long-term use. As a result, the new oil seal no longer fits and seals properly. It is not strictly necessary to replace or repair the entire shaft. Take a closer look at the dimensions first. It may be possible to fit with a slightly narrower or wider oil seal next to the groove. Alternatively, using the Speedi-Sleeve repair kit, repair the running surface under the seal.

The sealing process involves the interaction between the rotating shaft and the elastomeric material, resulting in a dynamic barrier that prevents fluid leakage and maintains system integrity.

Before installing the oil seal, it is essential that the oil seal, shaft and bore are not damaged. So, ensure that the surfaces the oil seal comes in contact with do not have any sharp points or burrs. The sealing lip is fragile, so any minor damage to it can cause leakage. Also, make sure the oil seal is clean. Even a small amount of dirt can cause a leak. Therefore, never use a pre-used oil seal for the assembly.

Table 1: The functions of the various components