Gear is worn out - need replacement

Thanks for posting. This looks either the 39-253LB and 39-253RB, or the 39-438B and 39-439B. The difference between these two sets of operators is the appendage at the end of the straight arm. The video below explains. In either case, for new covers see the 39-375 and 39-376, or the 39-451 and 39-452, depending on the style preferred.