substars
LVC Member
The revised idler pulley design has ridges on side to keep the belt aligned on the pulley, which solves the problem
Sorry if I am rehashing an old issue.
Dug into my 05's belt drive today after buying an idler pulley. FWIW for cheap impatient people like me: the Auto Zone pulley ($18) is not flanged but the Gates ($21) is, looks just like the revised Motorcraft design.