
One common reason leaking occurs in engines is that debris is caught in the fork seal, holding it open and allowing oil to sneak by. So, how do you fix this? This is where the little circular devices come in—oil seals.
Figure 5: JTEKT seal numbering system
Table 6: Codes and numbers used in seal numbers
The sealing lip is always made of a rubber or synthetic material. For oil seals with a rubber outer case (R, RST, GR, GRST), the rubber quality of the sealing lip and the outer case are the same.
What are Oil Seals?
What is Oil Seal | Purpose , Types of Oil Seal , Advantages
Shaft Hardness

Compounds for Automotive Power Train Systems

Spring The spring supplements the tightening force (i.e., the lip radial load) to ensure enhanced sealing performance and tight contact between the shaft and the sealing edge.The spring also prevents the deterioration of main lip sealing performance caused by high heat or other such factors.

GV
ERIKS
Metal O.D. wall
(with a reinforcing inner metal case)