Main and Connecting Rod Bearing Set +0.50mm BMW 135i 335i 535i X5 3.0L L6 N51 N52 N54 N55 11217627037

Over time, the internal bearings of the BMW N-series inline-six engines can suffer from excessive wear due to oil contamination or the high-stress demands of turbocharged applications, leading to dangerous copper exposure and rod knock. When the crankshaft journals require machining to remove scoring, standard-sized bearings can no longer maintain the critical oil film thickness needed for engine health. This +0.50mm oversized bearing set features advanced IROX® polymer coating, specifically engineered for modern Stop/Start systems and high-torque environments. The specialized coating significantly reduces friction during dry starts and provides superior fatigue resistance compared to traditional bi-metal bearings, ensuring long-term bottom-end stability and protecting your investment after a crankshaft regrind.