4.0 LITER. Accessory Drive Belt Tensioner. Assembled device that applies load to the drive belt. Bracket. Incl.Idler Pulley. Piston. Pulley that contacts the belt to apply tensioner load. Accessory Drive Belt Tensioner Assembly. Accessory Drive Belt Tensioner Pulley. Damper. SERPENTINE TENSIONER. Tension pulley bracket. Included with: Belt tensioner.