How do I loosen belt tensioner?

1. Disconnect the negative battery cable.

It is a good idea to make a simple drawing of the belt routing of your engine for installation reference before removing the belt.

2. Rotate the drive belt tensioner to relieve the belt tension. The procedure is as follows:
1. On the 4.6L, 5.4L and 6.8L engines, use a 1 / 2 drive tool or a special belt removal tool to rotate the tensioner in the proper direction as directed by the rotation arrow on the tensioner

2. While holding the tensioner back, remove the belt from around one pulley
.
3. Remove the belt from around the remaining pulleys.
To install:

4. Position the belt around the pulleys in the proper routing with the exception of one pulley. It is easiest to keep the belt off of the easiest pulley to access. Hold the belt tight with your hands and using the proper tool for your engine, rotate the tensioner in the correct direction and place the belt around the final pulley.

5. Release the tensioner slowly until it sits firmly against the belt.

If the tensioner does not touch the belt or the wear indicator marks are not within specification, the belt is routed incorrectly or the wrong belt has been installed.

6. Connect the negative battery cable.