http://tinyurl.com/moukp94
OTC 6698 Wheel Knuckle Vacuum Oil Seal Installer for Ford 2006 To Current F-450/550
Works on 2006 to current Ford F-450 F-550 4X4s having the vacuum-operated front axle
Correctly installs the seal onto the axle shaft and into the wheel knuckle
Prevents front hub vacuum leaks that would cause the 4WD to not engage