2007-2010 for Ford Explorer Sport Trac 4.0L/4.6L. 2006-2010 for Ford Explorer 4.0L/4.6L. Electronic-Viscous Fan Clutch, APPLY to the fan blade with a pitch of 2 ½” or over. The clutch might engage and match engine speed for up to 3 minutes during engine start-up resulting in a fan roar.
