The planetary assembly on a KitchenAid stand mixer rotates the attachments, allowing the mixer to mix, knead, or whisk effectively. With frequent use, this component can wear out or become damaged, leading to performance issues.
Common Causes of Planetary Assembly Failure
The planetary assembly is built to last, but several factors can lead to wear or damage over time:
- Frequent heavy use – Mixing thick doughs, large batches, or stiff ingredients can put extra strain on the assembly.
- Lack of lubrication – The grease inside the planetary assembly wears down over time, causing friction that leads to damage.
- Loose or worn gears – The internal gears can become stripped, affecting smooth rotation and making grinding noises.
- Debris buildup – Flour, sugar, or other ingredients can get trapped inside, leading to clogging and mechanical strain.
- Improper handling – Dropping the mixer or using excessive force when attaching accessories can lead to misalignment.
Signs You Need to Replace the Planetary Assembly
If your mixer exhibits any of the following issues, it may be time to replace the planetary assembly:
- Grinding or scraping noises while running
- Jittery or uneven movements
- Excessive shaking or wobbling
- Difficulty engaging or disengaging attachments
This is a repair you can handle at home with some basic tools and patience.
Tools and Materials Needed
- Replacement planetary assembly (compatible with your mixer model)
- Planetary grease
- Phillips screwdriver
- Small flathead screwdriver
- Snap ring pliers
- Punch
Safety Precautions
When working on any appliance, follow these safety guidelines to prevent accidents:
- Unplug the mixer before starting any work to avoid the risk of electric shock.
- Allow the mixer to cool if it was recently used.
- Take your time to handle parts carefully and prevent mistakes.
- Work in a well-lit, organized space to keep parts accessible and avoid losing small components.
- Keep children and pets away from the work area.
- Check the user manual for any model-specific instructions.
- Use gentle pressure when removing or installing parts to avoid damage.
- Wear insulated gloves to protect your hands from sharp edges and debris.
- Be cautious with wiring. Avoid touching exposed wires or terminals, and use non-conductive tools if necessary.
- Take photos or notes before disconnecting wires to simplify reassembly.
How to Replace the Planetary Assembly in a KitchenAid Mixer
Follow these steps to remove the old planetary assembly, install a new one, and reassemble your KitchenAid stand mixer.
Disassemble the Mixer and Remove the Old Planetary Assembly
- Unplug the mixer from the electrical outlet.
- Lift the beater slightly, turn it clockwise, let it drop, then pull it out.
- Lift the bowl off the mounting pegs to remove it.
- Use a Phillips screwdriver to remove the screw holding the trim band at the back of the mixer.
- Set the trim band aside.
- Use a Phillips screwdriver to remove the four screws holding the cover, two on each side.
- Lift the cover and set it aside.
- Use a Phillips screwdriver to remove the two screws that hold the speed control board.
- Carefully lift and move the speed control board out of the way.
- Use a small flat-head screwdriver to release the tabs on the sensor.
- Remove the sensor from the motor.
- Use a Phillips screwdriver to remove the four screws that hold the transmission cover.
- Lift off the transmission housing.
- Remove the accessory drive gear and set it aside.
- Clean the accessory drive gear if necessary.
- Remove the worm gear.
- Slide off any bearings and washers from the worm gear.
- Clean the worm gear with a soft cloth.
- Clean off old grease from gears and drive shaft.
- Use snap ring pliers to remove the snap ring from the shaft.
- Avoid overextending the snap ring to prevent bending.
- Lift out the beveled gear.
- Use a flat-head screwdriver if necessary to provide leverage when removing the beveled gear.
- Clean the beveled gear and set it aside.
- Use a punch to push out the pin that holds the worm follower gear.
- Remove the worm follower gear.
- Clean the worm follower gear.
- Drop the old planetary assembly out.
Install the New Planetary Assembly
- Grease the worm follower gear before reinstalling it.
- Apply planetary grease generously to the external and pinion gears of the new planetary assembly.
- Lift the new planetary assembly into the mixer.
- Place the worm follower gear onto the shaft and align the raised side as needed.
- Insert the pin to secure the worm follower gear to the shaft.
- Grease the beveled gear.
- Replace the beveled gear and make sure it rests on the shaft.
- Reinstall the snap ring using snap ring pliers.
Reassemble the Mixer
- Replace the transmission housing.
- Secure the transmission housing with the four screws.
- Reattach the speed control board.
- Reattach the sensor.
- Replace the cover.
- Secure the cover with the four screws.
- Reattach the trim band.
- Secure the trim band with the screw.
- Place the bowl back onto its pegs and snap it into place.
- Align the beater with the shaft and attach it by turning it counterclockwise until it locks.
- Plug the mixer back in.
- Test the mixer at different speeds to make sure everything is working correctly.
Read More: Stand Mixer Repair: Common Malfunctions and Fixes
How to Maintain Your KitchenAid Mixer After Replacement
After installing a new planetary assembly, proper care will keep your mixer running smoothly for years:
- Lubricate the gears regularly – Apply fresh grease every few years to prevent friction and wear.
- Clean the attachment hub – Wipe away any stuck ingredients after each use to avoid debris buildup.
- Check for loose parts – Tighten screws and inspect the planetary assembly periodically to catch any issues early.
- Avoid overloading the mixer – Stick to recommended ingredient quantities to reduce strain on internal components.
- Store the mixer properly – Keep it in a dry location and cover it when not in use to prevent dust accumulation.
To Recap
A KitchenAid mixer can last for years, but like any machine, it needs maintenance. If yours has been making odd noises, shaking too much, or struggling to mix, the planetary assembly might need replacing. It sounds like a big job, but with the right tools and a little patience, you can do it yourself.
The most important thing? Take it slow, keep track of the parts you remove, and apply enough grease. This small effort makes a big difference in how smoothly your mixer runs. Once everything is back in place, you’ll notice an immediate improvement, less noise, steadier movement, and a machine that works as it should.