Coat the sump flange with gasket-sealant and fit the flat parts of the gasket to it, ensuring that they are exactly positioned and joined.

Outer case

Offering a much more superior temperature resistance, polyacrylate seals are perfect for applications such as high surface speed oil.  Benefits include: 

Material Code ISO 1629

The major cause of extrusion and nibbling is stress caused by high pressure. This is commonly noticed when the oil seal has a chipped or nibbled look. In fact, in some cases, the surface of the seal tends to peel on its own, which makes it have a shaved look. What the stress does is that it increases the clearance gap between the mating edges, which causes the seal to get entrapped, and then leads to severe physical damage.