Rear main seals keep oil from leaking at the rear of the crankshaft. Most rear main bearing seals are made of either rope or synthetic rubber materials. Older engines usually have a rope-style seal, which is tricky to install. Molded-synthetic rubber-style seals are common today.

Federal-Mogul's Fel-Pro® brand makes rear main seals from different materials based on the application and the need for heat resistance. Select a material to learn more about its properties and recommended uses.