The front accessory drive belt is one multi-ribbed belt which drives the water pump, alternator, power steering pump, and the air conditioning compressor. For the engine and accessory operation, its condition and tension are important because tension that is too high brings bearing wear and tension that is low brings slippage, noise, component vibration, and failure of the belt. Since drivebelts are made from materials and bear high stress, they stretch and wear out and have to be checked on a regular basis. The serpentine belt also incorporates a tensioner that does not need adjustment at any time during its use or service. Each vehicle employs one or sometimes two belt, called V-ribbed belt or 'serpentine', which winds itself around a series of pulleys. The following are signs that show that the belt should be changed; To inspect the belt, turn off the engine and open the hood, by using a flashlight to check the following; Cheers. Closely acceptable conditions are crack on the rib side or small chunks missing from the ribs minute if large chunks are missing more than 1/2 inch from two adjacent ribs if noise is present the belt has to be replaced. The belts' interior has to be checked by twisting the belt to view the underside and the rest of its surface by touch for signs of wear. Tension is preset to avoid the need of readjusting it. To replace the belt, turn the tensioner anti-clockwise for 2.3L, 2.5L and 4.0L engines, or clockwise for the 3.0L engine to loosen the tension and remove the belt from the pulleys. When the tensioner is in the released mode replace a worn belt with a new one with proper fit and alignment with the pulleys, release the tensioner. If tensioner cannot tension the belt or bind or show some wear then remove the drive belt,Loosen the tension using the mounting bolt and for the 2011 4.0L V6 models, the air filter intake duct must be removed first. Here, it's just a reversal of steps that were followed when removing the tensioner; the bolt is tightened with the prescribed torque, then what follows is the reinstallation of the drivebelt in addition to air filter housing duct on the 2011 models.