The belt tensioner on the GMC 1500 model truck is a self-adjusting tensioner device that keeps the belt tight, as it travels around each accessory pulley. As the belt is driven around the engine accessories, the tensioner moves up with the movement of the belt, to keep it properly tensioned. If the spring becomes weak or breaks, the tensioner will not be able to tension the belt. If this occurs, replace the belt to prevent the belt from coming out of the accessory pulleys.
GMC 1500 Truck Install the Belt Tensioner Instructions
Locate the belt tensioner on the front, left side of the motor. Use the bolt in the middle of the pulley, connected to the bottom of the tensioner arm, to rotate the entire tensioner. Rotate the tensioner, counterclockwise, with the breaker bar and a socket. Slide the belt off the tensioner pulley, and hang it to the alternator with the bungee cord, to prevent the belt from slipping out of the accessory pulleys.
Locate the bolt in the middle of the tensioner arm. Loosen, and remove, the bolt, turning it counterclockwise with the ratchet and a socket. Pull the belt tensioner off the front of the engine block, and place it to the side. Position the new tensioner over the same area on the front of the engine block. Screw the bolt in the middle of the tensioner arm, and tighten it with the ratchet and socket.
Remove the bungee cord from the belt. Turn the tensioner, counterclockwise, with the breaker bar and socket. Slide the belt around the new tensioner pulley, and release the breaker bar. The new tensioner will then retract against the belt, until it is tight. Pull the breaker bar off the tensioner.
Crank the GMC 1500, and inspect the new tensioner, as the belt is traveling around it. Make sure that the tensioner is allowing the pulley to move freely up and down with the movement of the belt. Turn the engine off.
[via ehow.com]
