The automatic belt tensioner is responsible for the tension on the serpentine belt used in a Chevy Suburban. A spring-loaded pendulant arm connected to a smooth pulley makes the automatic operation work. A spring installed in the piece has a predetermined pressure, which is an important way to keep the right tension. Problems arise when the plastic separator plate between the spring and the tensioner body becomes compromised, resulting in an immobile arm.
Insert the ratchet into the square hole located in the arm of the tensioner, pulling the ratchet handle to move the arm of the tensioner away from the belt. This will relieve the tension on the belt. Lift the belt off the tensioner pulley, but do not remove the belt from any other pulley.
Remove the large center bolt securing the tensioner to the block, using the appropriate socket. Lift the tensioner out of the engine compartment.
Install the new tensioner, paying particular attention to the alignment stud on the rear of the tensioner spring body. This stud must be inserted into a corresponding hole in the block before the bolt is inserted. This stud keeps the tensioner from rotating when tension is applied to the belt. Insert the bolt and tighten securely.
Install the ratchet into the tensioner arm and pull the pulley away from the belt. Install the belt on the tensioner and relax the pressure on the ratchet allowing the tensioner to apply tension to the belt.
