This tensioner pulley maintains correct belt tension on the accessory drive of the host tractor’s engine. It is mounted on a fixed bracket and uses a sealed bearing to rotate freely, keeping the belt from slipping or flapping under varying load. A worn bearing produces a chirping or grinding noise at idle and can allow the belt to jump off the pulley, stopping the alternator or cooling fan. The pulley face is machined to match the original belt profile, so the belt rides at the correct height and does not wear unevenly. When replacing, ensure the pulley rotates smoothly by hand before tightening the mounting bolt to the specified torque.