KitchenAid Stand Mixer Stripped Worm Gear: Symptoms and... | appliancefaults.com

Technical Background:

The KitchenAid stand mixer uses a worm gear to reduce the motor's high RPM to a usable speed for mixing. This gear is designed to be a sacrificial part, protecting the motor from overload damage. When excessive resistance is encountered (e.g., overly thick dough), the worm gear is designed to strip, preventing more costly damage to the motor. There is no MCU or voltage path relevant to worm gear failure, as this is a mechanical failure.

Symptoms:

Homeowners often report a loud grinding noise, especially when mixing thicker doughs. The mixer might struggle or completely fail to turn, even though the motor is running. Some users also notice small metallic flakes or shavings in the grease around the planetary assembly.

Possible Causes:

Overloading the mixer with too much dough or a very thick mixture.
Using the wrong attachment for the task.
Insufficient lubrication of the gears.
Normal wear and tear over time.
Sudden impact or shock to the mixer (e.g., dropping it).

Solution:

1

Unplug the mixer from the 120V AC outlet. Lock Out, Tag Out (LOTO).
2

Remove the planetary assembly cover and attachment.
3

Locate and remove the retaining pin holding the planetary assembly to the mixer head using a punch and hammer. This may require some force.
4

Separate the mixer head from the base.
5

Open the mixer head housing by removing the screws with a 1/4-inch nut driver. Note the position of all internal components.
6

Identify the worm gear. It will likely be visibly damaged (stripped teeth). Clean out any debris.
7

Replace the worm gear. Apply new food-grade grease to the gear and surrounding components. Use only food-grade grease to prevent contamination.
8

Reassemble the mixer in reverse order. Ensure proper alignment of all parts. Test the mixer with a small batch of dough to verify proper operation.

Safety Warning:

Always unplug the mixer from the power outlet before performing any repairs. Lock Out, Tag Out (LOTO) procedures must be followed. Be careful when handling sharp tools and wear appropriate safety glasses. While there is no high voltage involved, working on electrical appliances always carries a risk.

Prevention:

Always follow the manufacturer's recommendations for batch sizes and mixing times. Use the correct attachment for the type of mixing you are doing. Regularly inspect and lubricate the gears with food-grade grease. Avoid overloading the mixer with excessively thick or heavy mixtures.

Expert Tip:

Before replacing the worm gear, check the motor brushes for wear. Worn brushes can contribute to increased resistance and put extra strain on the worm gear. Replace the brushes if they are worn to less than 1/4 inch in length.

Frequently Asked Questions

•What type of grease should I use for the gears?

You must use food-grade grease. Using non-food-grade grease can contaminate your food and pose a health risk.

•How often should I lubricate the gears in my KitchenAid mixer?

It's recommended to lubricate the gears every 1-2 years, or more frequently if you use the mixer heavily. Check the grease condition regularly.

•Where can I purchase a replacement worm gear for my KitchenAid mixer?

You can purchase replacement worm gears from appliance parts retailers online, or from authorized KitchenAid service centers.

KitchenAid Stand Mixer Stripped Worm Gear: Symptoms and Replacement

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What type of grease should I use for the gears?

•How often should I lubricate the gears in my KitchenAid mixer?

•Where can I purchase a replacement worm gear for my KitchenAid mixer?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: