This tension roller maintains proper belt tension on the rake head of a forage machine. It sits in the belt path between the drive pulley and the idler assembly, keeping the belt engaged with the tine bars. A worn roller allows belt slip, which reduces rotor speed and causes uneven windrow formation. The roller is built to the original geometry so it matches the bearing bore and shaft fit of the factory assembly. On replacement, inspect the bearing for wear and torque the mounting bolt to specification.