Grainger offers you more than 300 automotive belt tensioner and tensioner pulley options to serve your car and truck repair and maintenance needs. Your car's or truck's serpentine drive belt operates many separate parts simultaneously. Belt tensioners keep car and truck belts tightened to the proper tension. When a tensioner wears out, the pulley can lock up and the belt can slip off. If this happens, the tensioner should be replaced right away! Likewise, tensioner pulleys can become dry and defective. Inspect your drive belt components regularly. Keep your car or truck engine and all its parts running smoothly with a new belt tensioner and tensioner pulley from Grainger.