Below you will find a page-by-page contents list and a summary of the adjustments most often needed after a cable or lever has been replaced. Page numbers follow the manual (D-1, D-14 and so on). Joysticks on machines with servo controls are covered separately in Section L.
Contents by page: JCB 3CX / 4CX controls
| Pages | What the section covers |
|---|---|
| D-1 – D-3 | Steering column, tilt-adjustable and fixed: removal, dismantling and assembly |
| D-4 | Column switches: removal and replacement |
| D-5 – D-11 | Control rods and linkages: loader valve, excavator valve and stabiliser levers, auxiliary footpedal and its adjustment |
| D-12 – D-21 | Control cables: cab heater, boom lock with stop adjustment, engine throttle, park brake on synchro shuttle and Powershift machines |
| D-22 – D-24 | Anti-spill mechanism on 3C-14 (214e) and 3C machines |
| D-25 onwards | Shovel reset (return to dig): operation and adjustment, including 3C-14 (214e) and 3C machines |
Steering column and column switches
Two types of column were fitted (page D-1): a tilt-adjustable column with a gas strut and a fixed column in which a rigid link takes the place of the strut. The column is connected to the steering unit through a flexible coupling. On refitting, make sure the coupling clamp bolt locates in the cut-out on the shaft, and apply thread-locking compound to the steering wheel spinner knob thread and the other fixings specified. The column switches come off together with the front console (page D-4). The left-hand switch has a locating pin that engages a hole in the column and stops the mounting from turning. Disconnect the battery before starting work and, if the loader arms are raised, fit the mechanical safety strut. Column switches can be found in the switches category and cab parts in the cab category.
Control cables: adjustments after replacement
- Heater cables (page D-12). The side console carries two cables, one for the hot water valve and one for the recirculation flap. If the water valve cable is wrongly adjusted, the heater will not shut off completely. Set the valve lever to fully closed, turn the knob slightly clockwise from the “off” position, stopping just short of the “cold” mark, and clamp the cable outer with the clips in that position. Then check that the knob closes the valve fully.
- Excavator boom lock cable (page D-14). Route the new cable exactly as the old one was routed. With the handle down, take up the slack with the adjuster on the bracket: the cable should be taut but must not lift the lock. Next set the stop: raise the boom fully, engage the lock, release the pressure in the boom ram and position the stop block with a 3 mm gap to the boom profile. Tighten the block clamp bolt to 476 Nm. If the lock then fails to release, slacken the screw a further half turn and reposition the block.
- Throttle cable (page D-16) runs from the fuel injection pump lever on the left-hand side of the engine compartment to the accelerator pedal at the bulkhead and to the hand throttle lever in the right-hand console. After replacement, check that both the pedal and the hand lever work correctly.
- Park brake cable (pages D-18 – D-21). Before removal, record the setting dimension at the lever and, on refitting, restore the same dimension with the sleeve and locknut; apply thread-locking compound to the damper bracket bolts (torque 3 Nm). On synchro shuttle machines, connect the cable to the same hole in the caliper lever as before; with the lever in the off position the cable must not pull on the caliper lever. On Powershift machines, after connecting the cable check that the brake pack plates are free when the brake is released, and refit the cover on fresh sealant. Do not operate the machine until the cable has been adjusted as described in Section G “Brakes”.
Park brake cables are listed under brake system components, throttle cables under JCB Dieselmax engine parts and the boom lock cable under backhoe boom.
Valve control linkages and auxiliary footpedal
The loader and excavator levers are removed as an assembly together with their bracket through the opening in the cab floor (pages D-5, D-8). First disconnect the wiring to the switches in the handles (the transmission dump switch on the loader lever, the horn and the other switches on the excavator levers), park the machine on level ground, lower the attachments to the ground and disconnect the battery. The auxiliary footpedal (page D-10) is removed complete with its upper rod; on assembly check that the lever turns freely on its pivot, and renew the lever if the bush is worn. After assembly, adjust the linkages and, where fitted, the proximity switch under the pedal.
Shovel reset (return to dig)
This feature returns the loader shovel from the dump position to the digging position with a single movement of the lever (page D-25). With the shovel reset switch on, move the lever fully to the left and release it: the lever is held in detent until the shovel reaches the required angle. At that point a proximity sensor on the loader arm cuts the oil supply to the shovel rams and the lever returns to neutral. To adjust, lower the loader arms, set the shovel to the required position, stop the engine with the ignition left on and switch the feature on. Move the sensor rod with the nuts until the sensor LED comes on and goes off exactly in that position, and set the gap between the sensor and its target to 2 mm. Sensors are listed in the sensors category. To choose the right parts, send us the machine model, serial number and gearbox type.
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