This article describes the procedure for replacing the cutterhead bearings on the G0940 planer.

Before You Begin

⚠️ Disconnect the machine from power before performing any maintenance or repairs.

Wear cut-resistant gloves whenever handling the cutterhead. The carbide inserts are extremely sharp and can cause serious injury.

Replacing the cutterhead bearings requires extensive disassembly of the planer, including removal of the cutterhead assembly. Read through the entire procedure before beginning to ensure you have the required tools, supplies, and experience to complete the repair.

Important: This repair requires significant disassembly of the planer. If you are not comfortable performing advanced machine repairs, contact Grizzly Product Support before proceeding.

Tools and Supplies

Hand Tools

• T20 Torx wrench
• T25 Torx wrench
• 2.5 mm, 3 mm, 4 mm, 5 mm, and 6 mm hex wrenches
• #2 Phillips screwdriver
• 14 mm, 22 mm, and 24 mm open-end wrenches
• 15/16" (24 mm) socket
• Inch-pound torque wrench
• Snap ring pliers
• Dead blow hammer

Supplies

• Light machine oil
• T26419 Grease (or equivalent NLGI #2 grease)
• SB1365 (or equivalent ISO 68 oil)
• T33964 Dry Lubricant (or equivalent)
• Mineral spirits
• Shop rags
• Stiff brush
• Shop vacuum or compressed air
• Two 1-1/2" × 12" wood support blocks
• Scrap 2 × 4 material for supporting the cutterhead

Disassembly

1. Prepare the Machine

1. Disconnect the planer from power.
2. Remove the dust shroud as you would when indexing the carbide inserts.
3. Remove the elevation handle cap.
4. Remove the elevation handle cap screw using a 4 mm hex wrench.
5. Remove the elevation crank.
6. Remove the four top cover screws using a 5 mm hex wrench.
7. Carefully lift off the top cover.

Important: The return rollers are not retained and can fall out if the cover is tipped.

8. Remove the lower stop knob by removing its cap screw with a 4 mm hex wrench.
9. Remove both side covers.
10. Remove the drive belt using the Roll-Off Method described in the G0940 Owner's Manual.

2. Remove the Cutterhead Assembly

1. Remove the cap screw and washer from the top of the left leadscrew.
2. Temporarily reinstall the elevation handle.
3. Raise the cutterhead assembly to its highest position.
4. Loosen the four leadscrew nut set screws.
5. Carefully lift the cutterhead assembly straight up and off the guide columns.

Note: Machines equipped with the V2 cutterhead and red height-lock lever do not require removal of the brake assembly. However, once the cutterhead assembly clears the guide rails, the brake components may become loose. Keep track of these parts during disassembly.

6. If needed, remove the four screws beneath the guide columns and remove each guide column individually to make lifting the cutterhead assembly easier.

Tip: Removing the guide columns individually can make this step easier, especially when working alone.

7. Place the cutterhead assembly on a sturdy workbench supported by wood blocks so the carbide inserts do not contact the work surface.

3. Remove the Cutterhead

1. Support the cutterhead securely.
2. Remove the cutterhead pulley (Ref. 110).

Important: The M16 × 1.5 retaining nut (Ref. 112) uses left-hand threads. Turn the nut clockwise to loosen it.

If the retaining nut cannot be loosened with hand tools, an impact wrench may be helpful.

3. Remove the cutterhead shaft key (Ref. 106).
4. Remove the three bearing cover screws and bearing cover.
5. On the gearbox side, remove the three snap rings securing the sprockets.
6. Remove the chain cover.
7. Remove the sprockets, chains, and spacer bushing together.
8. Remove the gearbox mounting screws.
9. Pull the gearbox straight away from the cutterhead.
10. Support the cutterhead and remove the gearbox drive gear.

Note: The gearbox drive gear uses standard right-hand threads.

11. Using a brass drift or hardwood dowel and a dead blow hammer, carefully drive the cutterhead, bearings, and bearing cover out of the head casting.

⚠️ The carbide inserts remain exposed during this step. Handle the cutterhead carefully to avoid injury.

Replace the Bearings

1. Remove both cutterhead bearings.
2. Install the new bearings.
3. Install the bearing cover on the right side.
4. Reinstall the cutterhead into the head casting from the right side.
5. Tap the cutterhead into place with a dead blow hammer until it is fully seated.

Reassembly

Reassemble the planer by reversing the disassembly steps.

Before reinstalling the side covers and top cover, lubricate the planer according to the Lubrication section of the G0940 Owner's Manual.

Additional References

Some steps in this procedure are covered in greater detail in the G0940 Owner's Manual.

• Drive Belt Removal: See the Roll-Off Method in the Belt Replacement section (page 36).
• Lubrication: See the Lubrication section (page 32).

Helpful Tips

• Keep hardware organized as it is removed to simplify reassembly.
• Support the cutterhead whenever removing or installing bearings.
• Verify that all sprockets, chains, and keys are correctly installed before operating the planer.
• Confirm all fasteners are tightened securely before returning the machine to service.