Replacing an idler pulley in the serpentine belt system on a Ford 6.0 liter diesel engine becomes necessary if the pulley’s bearings fail. The idler pulley’s job is to route the serpentine belt from one engine accessory to another, deflecting the belt from one direction to another. The pulley consists of the pulley disc and an inner bearing ring. Over time, the bearing ring can wear out and eventually seize. Anyone with basic automotive repair skills can replace the idler pulley in about 30 minutes.
Raise the hood and plug the belt tensioner tool into the side of the serpentine belt tensioner. You can pinpoint the tensioner's location by referring to the belt routing diagram, which is printed on a sticker placed on the fan shroud. The diagram also shows the location of the idler pulley.
Move the belt tensioner aside by prying it gently with the belt tensioner tool. Move the belt off the tensioner pulley with your free hand. Let the tensioner return to its normal position once the belt is out of the pulley path.
Slip the belt off the tensioner with your hand. Remove the bolt from the center of the idler pulley with the socket set and then take the idler out of the engine well by hand.
Position the new idler pulley in place of the old one and thread the center bolt in by hand. Tighten it down with the socket set.
Slip the belt over the new idler pulley. Move the tensioner aside once more with the tensioner tool and then put the belt on the tensioner pulley before allowing the tensioner to move back to its normal position. Remove the tensioner tool and close the hood.
