Cummins 3644676 Connecting Rod Assembly

The Cummins 3644676 connecting rod is a critical drivetrain component designed for QSK series high-horsepower diesel engines. Manufactured from forged alloy steel with induction-hardened bearing surfaces, it converts reciprocating piston motion into crankshaft rotation under extreme cylinder pressures. The rod features a fractured split big-end design for optimal cap-to-rod alignment and includes precision-honed small-end bushing bore for wrist pin retention. This part supersedes earlier revisions 3643083 and 3640518, incorporating updated metallurgy and dimensional tolerances for improved fatigue resistance in continuous-duty cycles. Compatible with CM500, CM850 MCRS, CM2150 MCRS, and CM2250 K112 engine control modules. Each rod undergoes magnetic particle inspection and dimensional verification per Cummins QSK quality standards. Service replacement requires matching rod weight sets within engine to maintain rotating assembly balance.