SB Chevy Rear Main Seal 59-85 Silicone 2-Piece

The SB Chevy Rear Main Seal 59-85 Silicone 2-Piece is an essential component for maintaining the oiling system integrity of vintage Small Block Chevy and GM 6-Cylinder engines. Designed specifically for engine blocks manufactured between 1959 and 1985, this seal prevents lubricant from escaping the rear of the crankshaft, which is crucial for protecting the drivetrain and maintaining consistent oil pressure during operation.

This 2-piece silicone design addresses the specific sealing requirements of older engine architectures. Unlike standard rubber alternatives, the silicone construction provides enhanced thermal stability, allowing it to remain flexible even in high-heat environments typical of high-performance or heavy-duty use. This resilience ensures a long-term seal against the crankshaft flange, significantly reducing the risk of leaks that can lead to clutch contamination or oil loss.

When you purchase this component for a restoration or repair, you are selecting a part engineered to meet precise dimensional specifications for a reliable fit. The split-seal design allows for installation without removing the crankshaft in many applications, making it a practical choice for both professional engine builders and dedicated enthusiasts. It is an essential part of any comprehensive engine gasket kit or rear main bearing service.