Coats 85608497, Replacement-Transmission-Gearbox for most Coats Tire Changer; the common failure among Coats Rim Clamp machines. The gear inside the transmission wears out and causes the machine to lock up or stop moving the table. Although not necessary, we highly recommend replacing the rotary coupling or the Rotary Coupling Seals. This item comes complete with a pulley. This item supersedes the 185654 and 8185654 transmission gearboxes. It comes as pictured, and on some models, the worm shaft needs to be reversed.