The tensioner pulley on the Ford F-150 trucks equipped with a 5.0-L 302 engine is located at 10 o'clock compared to the engine crankshaft pulley. It mounts to the engine block just below the alternator. The tensioner pulley helps to maintain tension on the Ford's serpentine belt. Over time, the bearings inside the pulley can wear out and causes the pulley to pivot to the side. This creates uneven wear on the serpentine belt and could cause excessive heat buildup and premature belt failure.
Place a socket and ratchet onto the bolt that secures the tensioner pulley to the tensioner arm. Set the ratchet to counterclockwise, and rotate the pulley counterclockwise on the tensioner arm. Pull the belt off just the tensioner pulley.
Continue to turn the ratchet counterclockwise until the tensioner arm bottoms out against the positive stop. Turn the ratchet to loosen the bolt. Remove the bolt and the tensioner pulley from the tensioner arm.
Place the bolt into the center of the new pulley, and thread the bolt into the tensioner arm. Tighten the bolt using the socket and ratchet.
Reverse the ratchet to counterclockwise, and rotate the pulley counterclockwise. Slide the belt over the pulley.
