Paul S Jefferson , CO February 21, 2019 Appliance: KitchenAid Mixer KSM50P-2 Kitchenaid Mixer Ksm50p-2: Striped gears. How to replace Stand Mixer Center Vertical Shaft. I replaced both the worm gear and the hub gear. These are the gears that take the biggest beating. Lubed it all up and reassembled. Works like a new mixer. Do-It-Yourself Rating: Repair Time Estimate: 1-2 hours