○ Seals are designed to create a tight seal around the shaft by utilising a combination of lip geometry, surface tension, and lubrication. When the shaft rotates, the lip of the oil seal comes into contact with the shaft surface, creating a frictional force that generates heat. This heat helps to soften and conform the elastomeric material of the oil seal to the shape of the shaft, ensuring an effective sealing action.
- - Overheating
Auto Oil seal structure
Shaft and Bore Tolerances
The design of high-pressure oil seals is also critical to their performance. The seals must be able to maintain a tight fit between the moving parts, while also allowing for some flexibility to accommodate minor variations in the shaft or housing. This balance between rigidity and flexibility is essential for ensuring a reliable seal under high pressure conditions.
oil seal high pressure

To do this, turn the engine with a socket on the crankshaft pulley bolt until the rotor arm is pointing to the plug contact of the timing cylinder (usually No. 1, check in the car service manual), and the timing marks on or behind the pulley show exactly top dead centre ( TDC ).