Product Details: Outfit your vehicle to be Ready for the Road Ahead™ with optimized drive belt tension, with the Dayco 89935™ Heavy Duty Automatic Belt Tensioner. With a straightforward design, this replacement tensioner helps create the correct amount of tension on drive belts, delivering ample amounts of power to engine accessories such as AC compressors, water pumps, steering pumps, and alternators. Squeals, chirps, rattling sounds, or visible frays on belts are all signs and symptoms that a tensioner needs to be checked or removed. FleetPride is your First Click in Heavy Duty®.