2001-2016 Duramax 6.6L Left Head Gasket - 1.05MM Grade C- MAHLE - 55027

Seal it right the first time. The MAHLE 55027 is the updated OE-grade replacement for the 6.6L Duramax left side head gasket, produced by Elring — the original equipment manufacturer for Duramax engines. This gold-series gasket replaces the original MAHLE 54585 and delivers the same factory-level fit and sealing performance your engine was built with.
MAHLE's Wave-Stopper design uses concentric waves in the spring steel active layer to flex with changing combustion loads and pressures, preventing the micro-movement failures that cause leaks over time. Multi-layer steel construction with a polymer coating provides a durable, leak-free seal across the full range of operating temperatures — from cold starts to sustained high-load pulling.
At 1.05mm, Grade C is the standard service thickness and the correct choice for most head gasket replacements, including builds where the head has been machined. Compatible with all LB7, LLY, LBZ, LMM, and LML engines. Verify grade requirements with your engine builder before ordering.
Sold individually — left side (driver side).
Specifications
Part Number: 55027 (replaces 54585)
Grade / Thickness: C / 1.05mm
Side: Left (Driver)
Construction: Multi-layer steel, Wave-Stopper design, polymer coating
Brand: MAHLE / Elring
Fitment: 2001–2016 GM 2500HD / 3500HD 6.6L Duramax (LB7, LLY, LBZ, LMM, LML)