To install an oil seal properly, the shaft must be undamaged. This is so the oil seal can do its job properly on the one hand, and to prevent it from being damaged during fitting on the other. In addition, it is very important to lubricate the shaft, the sealing lip and the bore with plenty of grease. This will allow the oil seal to slide more easily over the shaft and prevent dry running after the first rotation. The oil seal may also come into contact with the keyway, thread or other grooves when sliding over the shaft. By taping or covering the shaft at the location of these irregularities with oil-soaked paper, the oil seal can be mounted without damage to the sealing lip.
There are different types of retainer oil seals available, each designed for specific applications and operating conditions. Some common types include lip seals, mechanical seals, and labyrinth seals. Lip seals are the most common type and consist of a flexible lip that makes contact with the rotating shaft to create a seal. Mechanical seals, on the other hand, use a set of rotating and stationary components to create a seal, while labyrinth seals have multiple barriers to prevent oil leakage Mechanical seals, on the other hand, use a set of rotating and stationary components to create a seal, while labyrinth seals have multiple barriers to prevent oil leakage

ERIKS type R (type A according to the DIN standard) is identical in shape to type M, but has a rubber outer case with metal reinforcement on the inside. The rubber creates a good seal in the housing, even if the housing has suffered minor damage or is not in its best condition for other reasons. The RST version has a dust lip. These types are often chosen to replace a type with a metal outer case because they are easier to install and can cope with minor damage to the groove, such as scratches.