Torsional vibration damper 331/50614 JCB, aftermarket

Torsional vibration damper 331/50614 is an aftermarket part for the JCB machines.

A damper is a spring or rubber flexible coupling between the engine flywheel and the input of the gearbox or hydrostatic pump. It absorbs the torsional vibration produced by each cylinder firing and keeps it from reaching the gears, shafts and pump. A damper with weakened springs or broken-up rubber causes rattling at idle and low revs, driveline vibration and gear chatter; in severe cases it breaks up and the drive is lost completely.

Specifications

Compatibility

According to the product card, 331/50614 is a torsional damper. The card also lists 334/F6263, another JCB number for the same part. Fit is confirmed by the part number. The catalogue also has the genuine version (option 1) and genuine version (option 2) of this part. Other parts are in Transmission.

Fitting

The damper is changed once the gearbox is separated from the engine. Clean the flywheel face, fit the new damper the right way round (usually with the hub boss towards the gearbox) and tighten the bolts in a cross pattern to the specified torque. Apply a thin film of the recommended grease to the input shaft splines. Do not let the gearbox hang on the damper hub while refitting; after assembly, run the engine and check for vibration and noise.