O.S. Engine OS23730000 Crankshaft Ball Bearing R 21RZ.37SZ  [OS23730000]

High precision crankshaft bearing details

This crankshaft ball bearing is supplied as a direct replacement for RC engine servicing and rebuilds. It supports the crankshaft journals inside the crankcase, reducing friction and helping to limit wear while the engine runs.

Fitting is usually done during a full engine rebuild or when checking for excess crankshaft play or rough free-spin. Ensure the bearing seat is clean, verify shaft runout, and install with correct orientation; many hobbyists use a bearing press or a soft-faced driver and gentle taps to seat the unit without damage.

When properly fitted, a smooth crankshaft bearing helps maintain steady idle and predictable throttle response by keeping the crankshaft rotation stable. It does not alter internal timing or compression, but it preserves the mechanical stability that influences overall engine performance.

Select this bearing when a worn or noisy crankshaft support appears during servicing to restore smooth rotation and prolong component life.