1N-4320: 127.61mm Outer Diameter Main Bearing

A Main Bearing is a plain or journal bearing that supports the crankshaft in place and allows it to rotate under inertia forces generated by the parts of the shaft and oscillating forces transmitted by the connecting rod. The Main Bearing is mounted in a crankcase and consists of two parts: upper and lower. The upper part of a main bearing has an oil groove on the inner surface. A main bearing has holes for passing oil to the feed holes in the crankshaft. Attributes: • Designed to withstand the harsh operating conditions • Maintains engine balance by evenly distributing the load across the engine block Applications: A Main Bearing is used in internal combustion engines to support the crankshaft and to reduce the friction that occurs between the crankshaft and the engine block.