The Extradig dipper on JCB backhoe loaders uses bolt-on wear pads that support and guide the inner dipper during extension and retraction. Over time, these pads wear and require inspection, adjustment, or replacement.
Related Contents:
Types of Wear Pads
- Top Wear Pads (A): Non-adjustable. Replace when worn to the limit.
- Bottom Wear Pads (B): Adjustable to compensate for wear. Replace when they reach their wear limit.
Inspecting the Top Wear Pads
- Park the machine on level ground. Engage the parking brake and shift transmission to neutral.
- Position the boom and dipper as shown in service diagrams. Retract the Extradig dipper so the bucket is clear of the ground and properly supported.
- Stop the engine and remove the starter key.
- Inspect the wear depth. Pads must be renewed when worn to the recess/chamfer depth. If nearing the limit, inspect more frequently than the standard service schedule.
- Ensure correct orientation when fitting new pads to avoid dipper or pad damage.
Torque Settings
- Adjusting Bolts (F): 56 Nm / 5.7 kgf·m / 41 lbf·ft
Adjusting the Bottom Wear Pads
- Park the machine on level ground. Engage the parking brake and put transmission in neutral.
- Support the boom and dipper in the recommended service position.
- Stop the engine.
- Clean the sliding faces of the inner dipper with a suitable solvent.
- Restart the engine and retract the Extradig dipper until the bucket is clear of the ground and dipper supported.
- Stop the engine again.
- Check the clearance between the inner dipper and top wear pad (A). The gap should be no more than 1.5 mm (1/16 in).
- If the gap exceeds 1.5 mm:
a. Remove one adjusting bolt (H) and discard one washer (J).
b. Refit and tighten the bolt (H).
c. Repeat for the remaining 3 bolts (H) on the same side.
d. Check the clearance again. If needed, repeat the adjustment on the opposite side.
e. Ensure the inner dipper remains centered within the outer dipper
- If the gap exceeds 1.5 mm:
More repair case for JCB machine,please refer to:JCB Trouble Repair