How to Replace the Gear Case on a DeWALT Grinder

The gear case consists of the gear case itself, the spindle gear, bearing and spindle (pre-assembled), and the spindle lock. Common issues with the gear case are a worn spindle gear, damaged threads on the spindle, a bad spindle bearing, or a cracked housing.

Let's get started.

REMOVING THE GEAR CASE   1. Remove the side handle.

a. Unscrew and remove the side handle from the grinder.

  2. Remove the guard.

a. Unscrew and remove the flange nut from the spindle.

b. Disengage the locking latch on the top of the guard.

c. Rotate the guard to disengage the locking tabs.

d. Remove the guard from the grinder.

  3. Remove the gear case cover.

a. Remove the (4) screws securing the cover to the gear case.

b. Remove the gear case cover from the grinder.

  4. Remove the gear case.

a. Remove the (4) screws securing the gear case to the motor housing.

b. Separate the gear case from the motor housing.

c. Use two screwdrivers to pry the flange away from the gear case.

INSTALLING THE NEW GEAR CASE

  5. Install the gear case.

a. Apply a small amount of grease to the teeth of the spindle gear on the new gear case.

b. Install the new gear case onto the motor housing.

c. Secure the new gear case to the motor with the (4) screws.

REASSEMBLING THE UNIT

  6. Reinstall the gear case cover.

a. Verify that the rubber seal is properly positioned within the gear case cover.

b. Install the gear case cover onto the gear case.

c. Secure the gear case cover with the (4) screws.

  7. Reinstall the flange.

a. Install the flange onto the spindle.

b. Press the flange firmly onto the spindle to seat the O-ring.

c. Depress the spindle-lock button.

d. Rotate the flange until it engages the hub.

  8. Reinstall the guard. a. Install the guard.

b. Rotate the guard to engage the locking tabs.

c. Secure the guard in the desired position with the locking latch.

  9. Reinstall the flange nut.

a. Thread the flange nut onto the spindle.

b. Secure the flange nut with the wrench (supplied with the grinder).

  10. Reinstall the side handle.

a. Thread the side handle into (either side of) the new gear case.