Before You Begin

⚠️ Disconnect the machine from power and disconnect the compressed air supply before performing this procedure.

Support the conveyor drums before removing the bearing housing to prevent unnecessary stress on the remaining components.

Replacing the front conveyor drum requires partial disassembly of the drive system and conveyor components. Read through the entire procedure before beginning to ensure you have the necessary tools and assistance.

Important: This procedure is easier with two people. The conveyor drum and bearing housing can be difficult to remove and align during reassembly.

Tools Required

• 9/16" wrench or socket
• 19 mm wrench or socket
• 5 mm hex wrench
• 3/16" hex wrench
• 1/4" hex wrench or impact driver bit
• Phillips screwdriver
• Flat-blade screwdriver
• Center punch
• Small hammer
• Dead blow hammer
• Pliers or locking pliers (optional, for removing the shaft key)
• Two 3-foot 2 × 4 boards for supporting the conveyor drums

Additional References

Some portions of this procedure reference components shown in the G0539 Owner's Manual.

Procedure

1. Support the Conveyor

1. Place two 3-foot 2 × 4 boards on the conveyor belt.
2. Raise the conveyor table until the boards lightly support both conveyor drums.

2. Prepare the Machine

1. Disconnect the machine from power.
2. Disconnect the compressed air supply.
3. Open both upper access doors and the lower right-side motor access door.
4. Remove the pulley cover (Ref. 660) by removing the two Phillips screws (Ref. 659).

3. Remove the Drive Belts

1. Loosen the motor belt tension nut (Ref. 104) using a 19 mm wrench or socket.
2. Raise the motor slightly and secure it to relieve belt tension.
3. Remove all three drive belts using the roll-off method.

4. Remove the Drive Pulley

1. Hold the pulley securely.
2. Remove each pulley cap screw one at a time.
3. Reinstall each cap screw into the unthreaded puller holes located approximately 60° away.
4. Gradually tighten each cap screw evenly, alternating between screws until the pulley separates from the split hub.

Tip: Tighten each screw only one or two turns at a time to keep the pulley pulling off evenly.

5. Remove the split hub (Ref. 655).

If necessary, insert a flat-blade screwdriver into the split and gently twist to loosen the hub.

6. Remove the shaft key.

5. Prepare the Drum for Removal

1. Loosen both set screws (Ref. 663) using a 5 mm hex wrench.
2. On the left side of the machine, remove:
   • The sanding belt
   • Block (Ref. 631)
   • Post (Ref. 630)
3. Remove the lever lock (Ref. 617).
4. Loosen the handle set screw (Ref. 624) and remove the handle (Ref. 623).

6. Remove the Bearing Caps

1. Remove both bearing caps (Ref. 615) by removing the three cap screws (Ref. 618) from each cap using a 3/16" hex wrench.
2. Carefully work each bearing cap loose by gently prying from alternating sides until it can be removed.

7. Remove the Bearing Housing

1. Remove the two Phillips screws (Ref. 421).
2. Swing the switch mounting plate (Ref. 463) out of the way.

The air lines do not need to be disconnected.

3. Before removing the spanner nuts, take a photo or note how much thread is exposed.

Important: The spanner nuts set the bearing preload. Matching the original position during reassembly helps restore the proper adjustment.

4. Remove the two bearing housing bolts (Ref. 464) using a 9/16" wrench or socket.

8. Remove the Front Conveyor Drum

This step is easiest with two people.

1. Have one person support the bearing housing on the left side of the machine.
2. While supporting the drum, gently move the bearing housing up, down, and side to side as needed.
3. From the right side of the machine, use a dead blow hammer to tap the drive shaft until the front conveyor drum and bearing housing slide free.

The rear conveyor drum remains installed during this procedure.

Tip: In some cases, the bearing housing can be pulled free by hand while a second person gently taps the drive shaft.

Reassembly

Install the replacement front conveyor drum (Ref. 632) by reversing the removal procedure.

When reinstalling the spanner nuts, match their original position to restore the bearing preload.

Before returning the sander to service:

• Verify the drive belts are correctly installed and tensioned.
• Confirm all set screws and fasteners are tightened securely.
• Rotate the conveyor by hand to ensure it moves freely before reconnecting power and air.

Helpful Tips

• Keep removed hardware organized to simplify reassembly.
• Support the conveyor drums throughout the procedure to prevent unnecessary stress on the remaining components.
• Take photos during disassembly to help verify the correct orientation of components during reassembly.
• Check belt alignment before operating the machine.