TENSIONER, Belt: Description: 3.6L
WARNING: This page is about a different car, the 2016 Jeep Wrangler and 2015 Jeep Wrangler. However, it is still accessible from the selected car via links, so may be relevant.
The automatic belt tensioner (1) is a hydraulically loaded arm and pulley assembly. The tensioner assembly is designed to apply constant pressure on the accessory drive belt to maintain proper belt tension.
The hydraulic strut (2) utilizes an internal spring and an one way valve that controls the oil pressure to the connecting rod. The valve allows the oil to build pressure in the piston to reduce the motion to the strut caused by the engines crank pulsations and allows for the proper tension to the accessory drive belt and pulleys.