Pump drive coupling 331/19919 JCB JS330/JS360, aftermarket

Pump drive coupling 331/19919 is an aftermarket part for the JCB JS330, JS360 and JS460 excavators. The card also lists 331/25745, 4449494, 239-6479, 324-4230.

A pump drive coupling carries torque from the engine flywheel to the hydraulic pump shaft and damps the engine's torsional vibration before it reaches the pump. In this type of coupling, elastic elements sit between aluminium parts; they carry the torque and take up small misalignment between flywheel and pump. One side of the coupling is bolted to the flywheel and the other joins a hub on the pump shaft splines. Worn or cracked elastic elements cause knocking with the engine running, vibration at idle and finally a complete loss of drive, leaving the machine with no hydraulics at all. If the elements are crushed, cracked or breaking up, replace the whole coupling. Check the bolt threads in the flywheel flange during the change.

Specifications

Compatibility

Other parts are in Hydraulic pumps.

Fitting

Misalignment between pump and flywheel shortens coupling life, so the pump mounting faces must be clean and the pump bolts tightened evenly. Use thread locker on the bolts where required.