How to Fix a KitchenAid Stand Mixer Beater That’s Not Spinning

Nothing’s worse than turning on your KitchenAid mixer and realizing the beater isn’t moving at all. Luckily, a non-spinning beater is usually something you can fix yourself in just a few minutes. Here’s how to troubleshoot your KitchenAid stand mixer and get that beater back in action—so you can get back to baking without missing a beat.

The information in this article may not apply to your specific appliance model. We recommend consulting your manufacturer’s documentation or contact us with any questions.

Why Isn’t My Beater Spinning?

If your mixer motor runs but the beater just sits there (or barely moves), it means the motor isn’t transferring power to the planetary gear (the part that holds the beater).

This is usually caused by:

• Worn worm gear: A key nylon gear inside your mixer is designed to fail (to protect the motor) when the mixer is overloaded. If this gear is stripped, the motor runs but nothing turns.
• Loose or broken planetary pin: The pin that holds the planetary assembly to the internal drive shaft can slip out or break.
• Loose planetary assembly: Over time, the planetary gear at the bottom of the mixer can come loose and stop engaging properly.
• Worn or stripped gears: Other internal metal gears can wear down, especially if the mixer hasn’t been maintained.
• Bent attachment shaft: If the shaft where you attach the beater is bent or damaged, it may prevent proper engagement.

Luckily, these issues are easy to diagnose and fix on your own.

What You’ll Need

Before you begin, gather these tools and supplies:

• Phillips and flathead screwdrivers
• Needle-nose pliers or a small punch
• Replacement worm gear kit (if needed)
• Food-safe grease (specifically for stand mixers)
• Clean rags or shop towels
• Plastic scraper or putty knife
• Small brush or compressed air

Always unplug your mixer before working on it.

Step 1: Confirm the Problem

Before taking anything apart, make sure the problem is what you think it is.

1. Plug the mixer into a working outlet.
2. Turn it on and listen for the motor.
3. If you hear the motor running but the beater doesn’t spin, it’s almost certainly a drivetrain issue, not the motor itself.

If the mixer doesn’t make any noise at all, that’s a different issue (likely electrical).

Step 2: Check the Beater and Shaft

Sometimes the simplest solution is the right one.

1. Remove the beater and inspect the attachment shaft.
2. Make sure the spring-loaded pin on the shaft is intact and moves freely.
3. Look for damage, bending, or excessive wear on the shaft or beater’s socket.
4. Reattach the beater firmly and try again.

If the beater still doesn’t spin, move on.

Step 3: Inspect the Planetary Assembly

The planetary assembly is the round, spinning part at the bottom of the mixer where the beater attaches. If it’s loose, it may not engage with the internal drive shaft.

• Look for a gap between the planetary and the mixer housing.
• Try to wiggle it by hand; it should feel secure and spin evenly.

If it’s loose, you’ll need to remove it and check the internal pin.

Step 4: Remove the Planetary

1. Turn the mixer upside down on a towel for stability.
2. Locate the small hole on the side of the planetary gear.
3. Use a small punch or pliers to push out the retaining pin.
4. Slide the planetary assembly downward and off the shaft.

Now you can see the internal drive shaft and pin groove.

Step 5: Check the Planetary Pin

With the planetary removed:

• Inspect the pin you just removed. If it’s bent, worn, or broken, replace it.
• Look at the shaft and the pin hole, make sure it isn’t stripped or worn.

If the pin and shaft look good, reassemble the planetary by sliding it back onto the shaft and reinserting the pin securely.

Turn the mixer on briefly to test. If the beater still doesn’t spin, the problem is likely in the gearbox.

Step 6: Open the Mixer Housing

The next place to check is inside the gearbox.

1. Remove the rear cover by unscrewing the two screws.
2. Remove the screws on either side of the motor housing and lift off the top cover.
3. You’ll now see the internal gears and motor assembly.

Step 7: Inspect the Worm Gear

The worm gear is a nylon gear inside the gearbox, and it’s the most common failure point when the mixer is overloaded.

1. Look for shredded plastic or missing gear teeth.
2. Check for metal shavings in the grease.
3. If the worm gear is stripped or worn, it needs to be replaced.

Step 8: Clean Out the Old Grease

Before replacing the worm gear:

1. Use a plastic scraper or putty knife to remove the old grease.
2. Wipe down all gears and housing with clean rags.
3. Remove any debris or bits of broken gear.

Step 9: Replace the Worm Gear

If the worm gear is damaged:

1. Remove the retaining clip and slide the old worm gear off the shaft.
2. Slide the new worm gear into place, making sure it aligns with the adjacent gears.
3. Replace the clip to secure it.

Step 10: Repack With Fresh Grease

Once the gearbox is clean and the worm gear is replaced:

1. Pack fresh, food-safe grease evenly over all the gears.
2. Don’t overfill; about 90% coverage is ideal to prevent leaks.

Step 11: Reassemble and Test

1. Replace the top motor housing and secure with screws.
2. Replace the rear cover.
3. Reattach the planetary assembly if you removed it earlier.
4. Plug in the mixer and turn it on to test at all speeds.

If the beater spins smoothly and quietly, success!

Where To Find Us 

If you need any replacement parts for your appliances, you can enter your model number at AppliancePartsPros.com to locate and order them quickly. Most orders arrive in just two business days, and we have tons of great information in our repair help section and YouTube videos to help you troubleshoot.

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