The serpentine belt tensioner keeps the proper amount of tension on the belt at all times. The belt tensioner is a two-part component that is made up of a spring-loaded arm and a roller pulley. When the engine is running, the serpentine belt travels under the roller pulley that is attached to the bottom of the spring-loaded arm. While the belt is traveling under the roller pulley, the pulley moves up and down with the movement of the belt. Replace the tensioner when it can no loner keep tension on the belt.
Open the hood on the vehicle and secure it in place. Inspect the top of the fan shroud for the serpentine belt routing diagram. Most diagrams are stamped to the top of the fan shroud or on the underside of the hood. Use this diagram to route the belt back around the pulleys in case the belt comes out of the pulleys when replacing the tensioner.
Locate the belt tensioner on the front of the engine. The belt will be routed underneath the roller pulley that is attached to the tensioner. Locate the bolt head in the middle of the roller pulley. The tensioner can be rotated from the bolt head.
Turn the tensioner either counterclockwise or clockwise with the breaker bar and a socket to relieve the tension from the belt. Reach under the roller pulley and slide the belt out. Allow the belt to hang downward toward the other pulleys.
Locate the bolt that secures the belt tensioner to the front of the engine. Most tensioner devices have a bolt head in the middle of the spring-loaded arm of the tensioner. Some tensioner devices are attached to a bracket that is attached to the front of the engine by two or three bolts. Remove the bolt or bolts from the tensioner device with the ratchet and a socket.
Pull the tensioner off of the front of the engine and match it to the new tensioner to ensure that the new tensioner is the correct size. Then, mount the new tensioner to the front of the engine and tighten the bolt or bolts back down tight with the ratchet and socket.
Rotate the tensioner from the roller pulley again with the breaker bar and socket, then slide the belt under the new roller pulley. Slowly release the tensioner and remove the breaker bar. As the tensioner is retracting against the belt, it will remove all of the slack out of the belt and bring it to the proper tension.
Inspect the belt to ensure that it is properly seated inside of each pulley. Then, crank the motor and let it run for about one minute. Inspect the belt and the tensioner as the engine is running to ensure that the belt is traveling properly around the new roller pulley and that the new tensioner is moving up and down with the movement of the belt.
Turn the engine off and shut the hood.
