Description: This tool is a huge time and money saver, use to installs the seal onto the axle shaft and into the wheel knuckle, preventing front hub vacuum leaks that would cause the 4WD to not engage, makes your job easier and more proficient and prevents comebacks. Application for: For 1998-2004 Ford F250 4×4 With Vacuum Front Axle For 1998-2004 Ford F350 4×4 With Vacuum Front Axle For 1998-2004 Ford F450 4×4 With Vacuum Front Axle For 1998-2004 Ford F550 4×4 With Vacuum Front Axle For 1998-2004 Ford Excursion 4×4 With Vacuum Front Axle Installation Detail: .