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F150 Serpentine Belt Replacement
How to Replace the Serpentine Belt on a 4.6L/5.4L V-8
Belt squeaking or squealing upon start up is the first sign that the serpentine belt needs to be replaced. Eventually, the noise will stop going away after start up and will occur continuously. Replacing the belt is fairly straight foward, as all that's needed is a 1/2 inch breaker bar or belt removal tool. The procedure is easier with two people, as the belt tensioner is made of soft aluminum and easy to strip if you don't maintain a solid grip on the 1/2 inch drive square socket. Should you strip the nut, a new belt tensioner is 3 bolts to install and your local auto parts store should carry one for under 50 dollars. To reduce the chances of stripping the tensioner socket, operate the breaker bar with one hand while pushing inward on the head of the bar with your other. Meanwhile, have a second pair of hands slip the belt off of the alternator.
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• Make sure you have the correct belt length and rib count. These vary depending on model year and engine.
• Push your tool clockwise (towards driver side) to release tension on the belt. While maintaining pressure on the tensioner, pull the belt off the top pulley (in our case, the alternator). Release the tensioner and completely remove the old belt.
• With the belt completely installed, release the tensioner and double check your work.