Description

The MB-3901171 0.50 mm Oversize Main Bearing Set is a premium OEM-grade crankshaft bearing set engineered for diesel engines that require 0.50 mm oversize bearings due to crankshaft machining, wear, or scoring. Oversized bearings restore proper crankshaft oil clearances, stabilize oil pressure, and ensure smooth, balanced rotation under demanding heavy-duty operating conditions. Constructed from high-strength tri-metal bearing alloy, these bearings provide outstanding fatigue resistance, heat stability, and long service life—making them ideal for severe-duty engines, fleet maintenance operations, and complete engine rebuilds. When crankshaft surfaces are machined undersize, the MB-3901171 bearings reestablish the correct tolerance, reducing friction, preventing knocking, and protecting against premature crankshaft failure. This oversize bearing set replaces OEM 3901173 , offering an exact-fit solution for diesel engine restorations and machining-based repairs. Key Features & Technical Advantages OEM-spec MB-3901171 0.50 mm oversize main bearing set Direct replacement for OEM 3901173 Designed for crankshafts machined undersize by 0.50 mm Restores factory oil clearances & stabilizes lubrication pressure Tri-metal alloy material provides maximum heat & fatigue resistance Reduces knocking, vibration, friction & engine wear Improves crankshaft support for smoother, more efficient operation Essential for professional rebuilds, machine-shop overhauls, & diesel fleet maintenance