Clutch housing (drum) 459/50411 JCB, aftermarket

Clutch housing (drum) 459/50411 is an aftermarket part for the JCB machines.

The clutch housing (drum) carries a clutch pack in the gearbox: the steel plates engage its internal slots, the friction plates sit on the hub and the hydraulic piston works inside it. The drum turns with the shaft and, when the clutch locks, passes torque to the gear. Steps worn in the slots by the plates, scoring where the piston runs or blocked oil holes stop the clutch engaging and releasing properly, making shifts harsh or the clutch slip. Steps in the drum slots are checked with a fine file; deep steps stop the plates moving freely and mean the drum must be replaced.

Specifications

Compatibility

According to the product card, 459/50411 is a clutch housing. The card also lists 445/30800, another JCB number for the same part. Fit is confirmed by the part number. The catalogue also has the genuine version of this part. Other parts are in Transmission.

Fitting

Assemble the pack on a clean bench: fit the piston with its seals into the housing, install the return springs and circlip with a press, stack the oil-soaked plates in order and measure the pack clearance. Once on the shaft, test the clutch with compressed air, and after the gearbox is assembled check the clutch pressures with a gauge.