At B&B we try to keep the rare tach drive parts in stock for the Tractors that are using tach drive Distributors. This gear is the cable side of the tach drive set. In most cases, if the tach drive isn't working, more than likely the mainshaft gear is wiped out. Replacing this gear alone will not repair the tach drive! A wiped out mainshaft gear will wipe this gear out almost immediately! The Distributor would need to be torn down to inspect the mainshaft gear first which is one piece and part of the mainshaft itself.