【Application】The front axle seal kit is Used In Dana 50 And Dana 60 Solid Front Axles 1998 1999 2000 2001 2002 2003 And 2004. For Ford Excursions F250 And F350 3/4 Ton And One Ton 4x4 Trucks With Front Leaf Spring Suspension. 【Function】The tube seal kit is used for the outer axle shaft seal to prevent dirt from entering and replace the old and worn seals.Rebuild the front axle for Ford Super Duty F250 F350 F450 . 【Total 6 pieces】2 inner knuckle oil seals that fit on the outer axle shaft, 2 outer tube dust seals that fit on axle housing tube end, 2 vacuum seal O-rings that are for the wheel hub bearing assy. 【Replacement】Inner knuckle oil seals Replace for part # 50491, Outer tube dust seals Replace for part # 50381,Vacuum seal O-rings Replace for part # 41784-2. 【Material】The front axle knuckle seal kit is made of hight quality steel and rubber,it has excellent corrosion-resistant, high-temperature resistance, anti-rust, oxidation resistance,suitable for long-term use. Front Axle Vaccum Knuckle Seal with Hub O-Ring and Dust Seals Kit (6 pcs) Fits for 1998-2004 Ford Super Duty F250 F350 F450 F550 Dana Super 50 60 Replace OEM Part # 50491, 50381, 41784-2