The shedding worm mechanism is mostly used on lathes of models C620, C620G, CS620 and C630. Repairing the worm gear mechanism is a routine overhaul project for this type of lathe. For such institutions, although the maintenance personnel are more familiar, the repair efficiency and the qualification rate are often quite different. Our factory has a good effect from the practice of the mold to the method of first removing the dial and then repairing the bearing surface to repair the shedding worm mechanism.