How to Replace the Lock Button Compression Spring on a Makita Grinder

Lock spring sprung? It's time to face the fix. Whether you are a master mechanic or a garage-based grinder, eReplacementParts.com provides the parts, procedures and facts you need to fearlessly fix what fails you.

The lock button compression spring is part of the lock button assembly on your grinder. Its job is to pull the lock pin away from the spindle gear when the button is released. Over time, it's possible for the spring to lose tension (or to break apart completely), allowing the lock pin to freely engage the spindle gear. If the grinder is activated (turned on) in this condition, it's not uncommon for the spindle gear to shear the end of the lock pin, resulting in lock assembly that does not work correctly (if at all).

This article provides step-by-step instructions for removing and installing the compression spring on a Makita grinder.

Let's get started.   REMOVING THE COMPRESSION SPRING [top] 1. Remove the side handle.

Unscrew and remove the side handle from the grinder.

  2. Remove the guard.

Loosen the lock-screw on the guard assembly.

Rotate the guard assembly to disengage it from the housing.

Remove the guard from the grinder.

  3. Remove the lock button compression spring.

Use a small screwdriver to (pry) disengage the pin cap from the shoulder pin.

Remove the pin cap from the gear housing.

Remove the compression spring from the shoulder pin.

  INSTALLING THE NEW COMPRESSION SPRING [top] 4. Install the lock button compression spring.

Install the new lock button compression spring onto the shoulder pin.

Install the pin cap (plastic button) onto the shoulder pin (over the spring).

Secure the pin cap to the shoulder pin using adjustable pliers.

    REASSEMBLING THE UNIT [top]  5. Reinstall the guard.

Install the guard assembly onto the grinder.

Rotate the guard assembly to engage the mounting plate.

Secure the guard with the (1) screw.

  6. Reinstall the side handle.

Install the side handle onto the grinder.

Tighten the side handle until secure.

You can't place a value on a job well done, unless you did it yourself. (Which you did.) Now you can place that value back into your own pocket. (Or into your business.) Not only did you refine your grinder at a fraction of the cost of replacement; you have expanded your skills far beyond the daily grind.

Find your next grind here.   [top]