GM LS Series Rear Main Seal 1-Piece

The SCE Gaskets GM LS Series Rear Main Seal 1-Piece is a factory-style replacement seal engineered for General Motors LS-series engines. This single-piece design with Viton construction delivers reliable crankshaft sealing in applications ranging from street performance builds to stock engine rebuilds, eliminating the complexity and potential leak paths of two-piece rear main seals while maintaining OEM-level fitment and durability.

Viton elastomer compound resists heat, oil degradation, and thermal cycling better than standard rubber formulations, critical for LS engines that commonly see elevated operating temperatures and extended drain intervals. The one-piece configuration eliminates the assembly and potential misalignment issues associated with split-style seals, reducing the risk of weeping at the crankshaft journal during the engine's service life. Precision machining ensures the seal diameter and contact surface mate exactly with OEM specifications, preventing premature wear on the crankshaft surface and avoiding costly damage to the block.

Buyers undertaking LS engine rebuilds—whether for LS1, LS2, LS3, LS6, or LSX variants—rely on this seal to maintain pressure integrity behind the crankshaft. It's equally suited for restorations, performance upgrades, and stock-replacement scenarios where a verified OEM-compatible component is non-negotiable. SCE Gaskets positions this product as a direct replacement for factory seals, making it the choice for builders who prioritize long-term sealing reliability and proper installation the first time.