This belt tensioner maintains the correct tension on the fan drive belt, preventing slip and ensuring consistent cooling airflow across the radiator and engine bay. It is mounted on the fan drive assembly and uses a spring-loaded arm to apply a constant force to the belt path. A failing tensioner typically produces a squealing noise at idle or causes the belt to flutter, which reduces fan speed and can lead to engine overheating. As an original-manufacturer component, it is built to the same pivot-arm geometry and spring rate as the assembly it replaces, so no adapter brackets or shims are needed during installation. When replacing, inspect the belt for wear and replace it if the tensioner has been run loose for an extended period.