Drivebelts, located at the front of the engine, play a crucial role in the engine's operation and its components. They are prone to wear due to their function and material make up, and should be inspected periodically. Most models have three belts, while some only have two. To inspect, with the engine off, open the hood and use your fingers to move along the belt, checking for cracks, separation of the belt plies, fraying, and glazing, which gives the belt a shiny appearance. Both sides of the belt should be inspected, which means you will have to twist the belt to check the underside. The ribs on the underside of multi-ribbed belts should all be the same depth, with none of the surface uneven. Belt tension can be checked manually, by pushing on the belt at a distance halfway between two pulleys. If the distance from pulley center-to-pulley center is between 7 and 11 inches, the belt should deflect 1/4-inch. If the belt travels between pulleys spaced 12 to 16 inches apart, the belt should deflect 1/4 to 1/2-inch. Belts that are routed over an idler pulley are adjusted by loosening the nut in the center of the idler pulley and turning the adjusting bolt. Belts that do not have an idler pulley are adjusted by moving the driven component in its bracket. To replace the belts, loosen the idler or component until the belt can be removed from the various pulleys. On multiple-belt applications, outer belts will have to be removed to access inner belts, but all belts should be replaced at the same time. Route the new belt over the various pulleys, then adjust the tension.