Crankshaft Pulley/Mass Damper

At the front of the crankshaft is a mass damper which drives the accessory drive belt for the ancillary components. A tuned torsional mass damper is incorporated into the crankshaft pulley that dampens vibration in the crankshaft produced by the combustion process. Each time a cylinder fires, torque is applied to the crankshaft via the pistons and connecting rods. The crankshaft deflects in reaction to the torque that creates a vibration when the torque is dissipated. The mass damper absorbs the vibration, reducing fatigue damage to the crankshaft.

A tuned torsional mass damper is incorporated into the crankshaft pulley to provide isolation and reduce accessory drive belt loads to the ancillary components. The crankshaft pulley is located over a roll pin that is press fitted into the front end of the crankshaft. Four bolts secure the crankshaft pulley to the crankshaft. An O-ring seal provides a seal between crankshaft pulley hub bore and the crankshaft nose outer diameter to prevent oil leakage during engine operation.

The crankshaft pulley has a timing mark that, when aligned to a corresponding timing feature on the front cover assembly, aligns the crankshaft to 50° After Top Dead Center (ATDC) on Cylinder 1. The mass damper assembly is not a serviceable component and must not be disassembled.