KitchenAid Mixer Transmission Housing: How to Spot Damage & Replace It

The transmission housing in a KitchenAid stand mixer protects the internal gears. Over time, it may crack or wear down, leading to grease leaks. The good news? You can replace it yourself in just a few steps. Follow this guide to get your mixer back in top shape without spending extra on repairs.

Signs Your Transmission Housing Needs Replacement

A damaged transmission housing can lead to performance issues. Watch for these signs that indicate it’s time for a replacement:

• Grease leaking from the mixer: This usually means cracks or gaps in the housing are allowing lubricant to escape.
• Strange noises during operation: Grinding, rattling, or clicking sounds could be caused by misaligned gears due to weakened housing.
• Reduced mixing power: If the mixer struggles with heavy dough or slows down unexpectedly, the gears inside may not be functioning properly.
• Visible cracks or wear: Inspect the housing for any signs of damage, including hairline fractures or worn-out sections.
• Burning smell or overheating: A faulty housing may lead to improper gear function, causing excess friction and heat.

Tools You’ll Need

• Phillips screwdriver
• Small flathead screwdriver
• Razor blade
• Drill with an 11/32-inch bit
• Replacement transmission housing (make sure it’s compatible with your model)

Check Part Compatibility

Before starting, make sure you have the correct transmission housing for your specific KitchenAid mixer model. Here’s how to find your model number:

• Look for a sticker or metal plate with the model information. It may be located:
  • On the underside of the mixer’s base
  • On the back of the motor housing
  • On the side of the base

Once you find the model number, write it down or take a picture for reference. Using the correct replacement part helps avoid fitting issues.

Safety First

Whenever you’re working on an appliance, safety should be your priority. Keep these precautions in mind:

• Unplug the mixer or turn off the circuit breaker before starting to avoid electric shock.
• Let it cool down if it was recently in use.
• Work in a well-lit area for clear visibility.
• Keep the workspace organized—remove clutter and keep pets and children away.
• Check the user manual for any specific safety guidelines.
• Use gentle pressure when removing or handling parts to avoid damage.
• Wear insulated work gloves to protect against sharp edges.
• Avoid direct contact with wires unless using an insulated tool or gloves.

How to Replace the Transmission Housing in a KitchenAid Stand Mixer

Follow these steps to remove the old transmission housing and install a new one to keep your mixer running smoothly.

Removing the Old Transmission Housing

1. Unplug the mixer from the electrical outlet.
2. Lower the mixer bowl to the down position.
3. Lift the beater, turn it clockwise, and let it drop down to remove it.
4. Lift the bowl off the mounting pegs and pull it out.
5. Use a Phillips screwdriver to remove the screw securing the trim at the back of the mixer.
6. Pull the trim off and set it aside.
7. Use a Phillips screwdriver to remove the four screws (two on each side) securing the top cover.
8. Lift off the cover and set it aside.
9. Use a Phillips screwdriver to remove the two screws holding the speed control board in place.
10. Lift the speed control board and move it out of the way.
11. Use a small flat-head screwdriver to press the tabs on each side of the sensor.
12. Pull the sensor out of the motor.
13. Swing the speed control board further out of the way.
14. Use a Phillips screwdriver to remove the four screws holding the transmission housing in place.
15. Carefully lift the transmission housing off the mixer.
16. Push the hub attachment gear into the housing and lift it out.

Installing the New Transmission Housing

17. If the bearing is stuck on the shaft, carefully remove it.
18. Clean any grease or debris from the area where the transmission housing will be installed.
    Place the hub attachment gear into the new transmission housing.
19. Align the new transmission housing properly.
20. If the locator pins from the original housing broke inside the base, carefully remove or drill them out.
21. Turn the hub gear slightly to align the teeth.
22. Press the housing down completely into place.
23. Use a Phillips screwdriver to secure the four screws holding the new transmission housing.

Reassembling the Mixer

25. Lift the speed control board back into position.
26. Use a Phillips screwdriver to secure the two screws on the speed control board.
27. Align the sensor properly and push it back into the motor until it locks in place.
28. Place the top cover back onto the mixer.
29. Use a Phillips screwdriver to reinstall the four screws securing the top cover.
30. Reattach the trim ring at the back and secure it with its screw.
31. Align the bowl on the mounting pegs and place it back onto the mixer.
32. Push down on the back of the bowl to snap it into place.
33. Line up the beater on the shaft, making sure the pin fits into the cutout.
34. Lift the beater into place and turn it counterclockwise to lock it.

Testing the Mixer

35. Plug the mixer back into the electrical outlet.
36. Turn the mixer on and test all speed settings.
37. Listen for any unusual noises and check that the beater moves correctly.

Also Read: How to Fix Stand Mixers That Won’t Turn On

Preventative Maintenance Tips

Regular maintenance can help extend the life of your KitchenAid stand mixer and prevent costly repairs. Follow these tips to keep it running smoothly:

• Keep the mixer clean: Wipe down the exterior and remove any food residue after each use.
• Inspect the transmission housing regularly: Check for signs of wear or leaks to catch issues early.
• Lubricate gears as needed: Over time, grease can dry out. If your mixer starts making noise, it may need fresh lubrication.
• Avoid overloading the mixer: Stick to the recommended capacity for your model to prevent strain on the motor and gears.
• Store in a dry place: Moisture can cause rust or weaken certain components over time.
• Tighten screws and fasteners: Vibrations from mixing can loosen hardware, leading to misalignment or other issues.

Next Steps

Now that your KitchenAid mixer is working again, don’t just forget about it. A little upkeep can keep it running smoothly for years. Wipe it down after use, check for leaks now and then, and listen for any strange sounds. Catching small issues early can save you time and effort later.

If that grinding noise ever comes back, at least you’ll know what to do. And if you think swapping out the transmission housing was a challenge, just wait until it’s time to refresh the grease inside. But that’s a problem for another day. For now, enjoy mixing without worry.