How to Change Grease in Polishers

Last Updated January 16, 2025

Polishers like the Harbor Freight Bauer Dual Action 6″ Polisher come packed with grease to keep the tool running smoothly. Unfortunately, the grease the manufacturers use is of low quality. This creates a lot of noise and vibration and can even cause premature failure.

If you want to minimize all that noise and vibration while ensuring a longer lasting tool, you need to replace the factory grease with a premium lithium grease. Here is a step-by-step guide to replacing the grease in a polisher.

Step 1: Remove the Backing Plate

Step 2: Remove Plastic Cover Using a Flat Edge Screwdriver

Step 3: Remove the counterweight using a Phillips Head screwdriver

NOTE:  Sometimes these tools are assembled using low quality machine screws.  Make sure the tip on your Phillips head screwdriver is in good shape to avoid stripping out the head of the machine screw.

Step 4: Remove the rotating assembly

It can be tricky to see but the rotating assembly has 2 flat sides that you’ll need to grab onto with a pair of groove joint pliers. 

Note that it’s a TIGHT fit to get the jaws of a set of groove joint pliers inside the housing.  Groove joint pliers have the thinnest set of plier jaws out of all my wrenches and can be purchased at most local hardware stores.

If you struggle to fit groove joint pliers inside the metal housing, as an option, you can grind the outer sides of the jaws down using a bench grinder.

To remove the rotating assembly, you’ll need to lock-up the rotating assembly on the top side of the polisher while grabbing onto the rotating assembly with the groove joint pliers.  The polisher comes with an Allen wrench to lock-up the rotating assembly so you can unscrew it using the groove joint pliers, but I found a T-handle Allen wrench easier to grip while loosening the rotating assembly.

After inserting, tightly grip the rotating assembly and break it free.  It helps to have a buddy when doing this, but it can be done by yourself.

Once you break free the rotating assembly, you can then spin it completely off using your fingers.

Step 5: Remove the Housing

Be careful not to strip out the head of the machine screws.

Step 6: Remove the Gear Housing

After removing the 4 machine screws, the gear housing should lift straight off exposing the gears and the factory grease.

Step 7: Remove the Factory Grease

I used my fingers and some paper towels.  If you really want to go nuts cleaning out as much of the grease as possible, have some Q-tips handy.

Step 8: Replace Grease

Pack the inside of the gear housing with a premium quality lithium grease.

Apply grease to both sides of the gear housing.

Step 9: Reassemble the Tool

Mike’s Technique Tip: Have a small bowl (or screw holder) handy to hold all the tiny stuff so you don’t lose it during this project.

Snug each machine screw down until tight.

Reinstall the rotating assembly.  

Reinstall the counterweight.

To keep the rotating assembly from spinning while tightening the counterweight screws, you can block and wedge the counterweight using a flat head screwdriver like you see in the picture below.

Reinstall the backing plate, be sure the compression washer is still attached to the 5/15” threaded stud.

Reattach the plastic housing.

Step 10: Test the Polisher

After you have reassembled the polisher, now it’s time to test it out.

Success!

The polisher is noticeably quieter and also there’s less vibration, too.

Time to get to work de-swirling a 1936 Ford Pickup Streetrod.

Final thoughts…

As you can see from the pictures above, you can disassemble the polisher, replace the factory grease with a premium grease and then reassemble the polisher in around 30 minutes using simple hand tools.

The benefits make this mod more than worth the time and energy required to do the grease swap.  Not only will the tool run quieter and have less felt-vibration, but chances are also good it will last longer too.

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Questions?

If you have any questions about how to do the grease-swap in your Harbor Freight Polisher, feel free to post them below to this blog article.

Do you have a passion for making cars shiny?

• Would you like to take your detailing skills to a higher level?

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Sincerely,

Mike Phillips
Chief Education Officer for Dr. Beasley’s
Mike@drbeasleys.com
760-515-0444