An overview of the different standard types of oil seals and their main characteristics is shown below.
One way to recognize an improperly installed seal is by checking whether or not there is uneven shearing of the rubber after use. If this is evident, adjust by aligning the installation tools properly before pressing the seal into place.
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Always start by making sure the oil seal is facing the right direction. The oil seal must be positioned with its spring to the side of the medium to be sealed. The oil seal must then be pressed into the bore. It must fit tightly (H8 in the groove is recommended). Use appropriate tools for this, such as an impact socket set, to ensure that the force is applied evenly during pressing. The oil seal must never be hammered into the bore with brute force, but eased in.