Transmission valve block 459/M5109 JCB, genuine

For the JCB machines: transmission valve block 459/M5109, a genuine JCB part.

The block is chosen by part number for the gearbox type and version, as the number of solenoids, connections and internal passages can change over the years. A block supplied «empty» comes as a body without solenoids and some valves, and the sound parts are moved across from the old block. Before replacing the block, check the solenoid connectors and resistance, since the fault often lies not in the block but in a solenoid or the wiring. The block body's mating face must be flat and unscratched, as even small damage can let oil cross between passages.

Specifications

Compatibility

According to the product card, 459/M5109 is a transmission valve block. The card also lists 459/M3087. Fit is confirmed by the part number. Other parts are in Transmission.

Fitting

Before the change, make the machine safe, disconnect the battery negative and clean around the block. Mark and unplug the solenoid connectors, remove the block and refit with a new gasket, tightening the bolts in a cross pattern to the specified torque. After assembly, check the oil level, try all directions and gears and measure the clutch pressures with a gauge. In the first hours after the repair, watch the transmission oil temperature and level, and do the first oil and filter change earlier than usual.