TORSIONAL VIBRATION DAMPERS – TVD
Essentially an upmarket term for a crankshaft pulley that incorporates a rubber damper, that is sandwiched between a pair of metal sections – these should be inspected for their condition after removal. As TVDS absorb vibrations from the crankshaft, they enhance the life of the auxiliary belt that, in recent years, has been responsible for driving an increasing number of components, from the alternator to the air-conditioning compresssor. Apart from increasing the risk of the auxiliary belt failing and wrapping itself around the timing belt, vibrations that are caused by a failing TVD can cause the timing belt to delaminate – for this reason, it is inadvisable to fit solid pulleys if a TVD was fitted originally. Worse still, the TVD can break apart and introduce fragments into the timing belt housing.
For further information about inspecting a worn TVD, please make reference to
Note that other parts of the auxiliary belt system, including any idlers, tensioners and even alternator overrun pulleys, should be inspected for rough movement and/or seizure.