Step 2: Using the 18mm wrench, loosen the belt tensioner.
NOTE: You DO NOT need to fully remove the belt for this installation! In fact, not doing so can make it much easier, as you won't have to reposition the belt.
Step 3: Using the 15mm wrench, loosen the bolt (1) that holds the idler pulley to the assembly. You can now pull the idler pulley from the vehicle.
Step 4: Remove the spacer from the old idler pulley's mounting bolt, and slide it onto the new mounting bolt.
Step 5: Mount the new idler pulley by tightening the 15mm mounting bolt (1).
Step 6: Using the 18mm wrench, tighten the belt tensioner, until the belt is taut.
NOTE: When tightening the tensioner, make sure that the belt hasn't slid off of any of the pulleys!
These Part Change / Installation Instructions Apply to
04 2004, 03 2003, 02 2002, 01 2001, 00 2000, 99 1999 Ford Mustang 3.8L Engine Belt Idler Pulley Replacement Instructions