Jim N Pillager , MN January 20, 2015 Appliance: KitchenAid Mixer KSM50P-2 Kitchenaid Mixer Ksm50p-2: Nylon gear was chewed up. How to replace Worm Gear. To diagnose the problem I disassembled the power head and ordered the required parts. I installed the parts, greased it up good and reassembled the mixer. It is now in great operating condition. Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes