Description

The Cummins Connecting Rod Bearing 3901431 (0.25 mm undersize) is a precision-engineered diesel engine bearing designed for engines where the crankshaft rod journals have been machined 0.25 mm undersize . This bearing is essential during engine rebuilds to restore proper oil clearance, smooth rotation, and reliable load support after crankshaft regrinding. Manufactured using high-quality multi-layer bearing alloys , the 3901431 rod bearing is built to withstand high combustion forces, heavy loads, and continuous high-RPM operation common in Cummins diesel engines. The bearing construction promotes excellent fatigue resistance, effective heat dissipation, and stable lubrication film retention under demanding operating conditions. Designed for accurate fitment and precise oil clearance , this Cummins undersize connecting rod bearing helps reduce friction, prevent metal-to-metal contact, and extend crankshaft and connecting rod service life. Using the correct undersized bearing is critical to maintaining oil pressure, minimizing wear, and ensuring long-term engine reliability after crankshaft machining. This connecting rod bearing is widely used in Cummins diesel engine rebuild and overhaul applications , including on-highway trucks, industrial engines, and heavy-duty equipment requiring precise undersized bearing components.