Crankshaft vibration damper
Absorbs twisting vibration at the front of the crankshaft.
On the front nose of the crankshaft, usually combined with the belt pulley.
An inertia ring bonded in rubber or running in viscous fluid counters torsional vibration from the firing pulses.
A shock absorber for the crank’s own wobble.
A wobbling pulley, separating rubber or unusual vibration needs inspection before engine damage follows.
Usually condition-based rather than a routine replacement. Lubrication, overheating and the exact engine affect wear.
Internal-engine work is usually labor-intensive. Diagnosis and the engine code determine the repair scope.
Long BMW inline-six crankshafts rely on a tuned damper because six throws in a row can twist at certain speeds.
BMW petrol and diesel engines; petrol-only systems are identified individually.