Brian S Cincinnati , OH January 25, 2016 Appliance: Model KITCHENAID PRO 600 Kitchenaid mixer stopped working Easily opened the case and found the worm gear was stripped. Cleaned everything, replaced the gear, packed it with grease, and closed it back up. Works better now than when it was brand new. Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes