When the total eccentricity is excessive, the sealing edge of the seal lip cannot accommodate shaft motions and leakage may occur.
Total eccentricity is the sum of shaft runout and the housing-bore eccentricity.
Total eccentricity, shaft runout and housing-bore eccentricity are generally expressed in TIR (Total Indicator Reading).


Types of Oil Seals in Application
Metal cased design
THE DIFFERENT SIZES OF OIL SEALS
Proper care and maintenance of square rubber gaskets are essential to ensure their longevity and effectiveness. Regular inspection for signs of wear, damage, or degradation is important to prevent leaks and maintain the integrity of the seal. Replacing worn or damaged gaskets promptly can help prevent costly repairs and downtime.
When selecting engine oil seals, power steering oil seals, and motor oil seals, it is essential to prioritize quality, durability, and compatibility with specific vehicle models. High-quality oil seals are designed to withstand the demanding conditions of automotive operation, providing reliable sealing solutions that contribute to the overall performance and safety of the vehicle. Choosing reputable suppliers and manufacturers known for producing high-quality oil seals is crucial to ensure the reliability and longevity of these critical components.
Rotary Wheel Of Auto Parts
ERIKS type M (type B according to the DIN standard) has a single metal casing and rubber sealing lip. Since the casing is made of metal, it must be fitted in a well-finished, undamaged groove. Large volumes of oil seals with metal casings are often cheaper, which is why they are often used as original equipment in machines. However, if an oil seal has to be replaced, types with a rubber exterior (type R or RST) are easier to fit. Type MST is similar to M and commonly used. The difference is the dust lip in the MST oil seal that prevents dust and dirt reaching the sealing lip, and extends its service life in dusty environments.
Set the gasket on the block and make sure that all holes are perfectly aligned before refitting the head (See How to remove a cylinder head ).
Lubricant Amount - Seals will always perform best when lubricated, however in some machines there are more likely to be dry spells. For these cases, selecting a leather or PTFE seal will be beneficial, as both can operate with less lubrication than others.
An oil seal type that is resistant to oils, fuels, and solvents, fluorosilicone also offers temperature stability. Primarily found in aerospace fuel applications and automotive fuel emission control, this o ring material is fast becoming popular in more and more oil-based applications across a wide spectrum of industries.
There is a British Standard laid down for the control of synthetic rubbers. BS 3574 (1989) helps to determine shelf life – for instance, Nitrile (NBR) and Polyacrylic (ACM) are Group ‘B’ rubbers and have a 7-year life, whilst Silicone (VMQ) and Fluoroelastomers (Viton®) are Group ‘C’ rubbers and have a 10-year shelf life. PTFE and Leather do not come into this category but like the others should be kept in the original packing for as long as possible away from direct light, dust, and humidity. Ozone, which can also be produced by battery-driven forklift trucks has a very bad effect on synthetic rubbers. Finally, protect the sealing lip – DO NOT hang the seals on nails, wire etc.
The speed at which an oil seal can operate effectively depends on the previously outlined conditions together with the design of the seal itself. Some designs allow for a range of maximum peripheral speeds and are therefore more suitable for larger shaft diameters. Speeds below and above the recommended range can cause friction and thus impact the sealing material.