Spicer Front Axle Master Wheel End & Vacuum Seal Kit for 1998-2004 Ford Super Duty (Dana 50 / 60, Both Sides)

Restore prompt Electronic Shift-on-the-Fly (ESOF) automatic 4WD engagement and lock out destructive trail grit with this genuine Spicer Front Axle Wheel End Master Vacuum Seal Kit. Curated as a complete, dual-side service package for 1998–2004 Ford F-250/F-350 Super Duty trucks and 2000–2005 Ford Excursion 4x4s, this premium OEM seal bundle provides all the necessary heavy-duty multi-lip seals and o-rings to fully refresh both the driver and passenger side front wheel ends simultaneously.

On First-Generation Super Duty platforms, the automatic pulse-vacuum 4WD system relies entirely on a perfectly sealed wheel end environment. Over time, the primary inner knuckle seals degrade due to axle shaft rotation, extreme temperatures, and road salt intrusion. When these seals fail, the vacuum dropped by the ESOF pump bleeds directly to the atmosphere. This system vacuum loss prevents the automatic locking hubs from pulling into place when you flick the dash switch, leaving you stuck in two-wheel drive. Furthermore, failing seals allow water and mud to pass directly into your outer axle tubes, which accelerates wear on your internal spindle needle bearings and axle u-joints.

This original equipment manufacturer (OEM) master service package eliminates vacuum loss by bundling a pair of premium Spicer main vacuum knuckle seals with the updated outer axle tube dust seals and inner hub o-rings. Sourcing a genuine Spicer bundle ensures you receive specialized elastomeric compound configurations, advanced multi-lip sealing geometry, and exact factory dimensions that cheap aftermarket clones cannot match.

Kit Contents (Complete Set Services Both Driver & Passenger Sides):

• (2) Genuine Spicer Premium Multi-Lip Front Axle Hub Vacuum Seals (Part # 50491)

• (2) Genuine Spicer Updated Front Outer Axle Tube Dust Seals (Part # 50381)

• (2) Genuine Spicer Wheel Hub Assembly Outer O-Rings

Kit Highlights:

• Complete Left & Right Overhaul: Supplies exactly enough factory-matched primary vacuum seals, tube dust boots, and hub o-rings to seal both front wheel ends simultaneously.

• Restores ESOF 4x4 Function: Eliminates system vacuum drop-off, ensuring your automatic locking hubs receive adequate vacuum signal to lock in instantly when 4WD is requested.

• Advanced Contaminant Exclusion: Updated outer tube dust seals fit snugly at the end of the axle housings, blocking mud, moisture, and road brine from migrating down into the tubes.

• Genuine Spicer OEM Quality: Precision-molded by the vehicle's original axle manufacturing supplier to guarantee a flawless press-fit into your factory steering knuckles and wheel hubs.

Vehicle & Axle Fitment:

• Axle Profile: Solid Monobeam / Leaf-Spring Front Dana 50 and Dana 60 Axles equipped with open knuckles and pulse-vacuum automatic hub configurations. Does not fit later 2005+ coil-spring front axle assemblies.

• Ford F-250 Super Duty: 1998, 1999, 2000, 2001, 2002, 2003, and 2004 4x4 truck models.

• Ford F-350 Super Duty: 1998–2004 Single-Rear-Wheel (SRW) and Dual-Rear-Wheel (DRW) 4x4 truck models.

• Ford Excursion: 2000, 2001, 2002, 2003, 2004, and 2005 4x4 SUV models.

• Position: Front Outer Axle Wheel Hubs — Left (Driver) and Right (Passenger) Sides (1 Kit Services the Entire Front Axle)