Spicer Front Knuckle Hub O-Ring & Axle Dust Seal Kit for 1998-2004 Ford Super Duty (Dana 50 / 60, Single Side)

Restore your Electronic Shift-on-the-Fly (ESOF) automatic locking hubs, block invasive trail debris, and protect your front-end components with this genuine Spicer Front Knuckle Hub O-Ring & Axle Dust Seal Kit. Specifically engineered to refresh the steering knuckle sealing boundaries on 1998–2004 Ford F-250 to F-550 Super Duty trucks, this single-side refresh package replaces deteriorated, leaky vacuum seals and worn dust boots.

On classic Ford Super Duty 4x4 platforms, the automatic front locking hubs rely entirely on an airtight vacuum environment inside the steering knuckle to pulse-actuate 4WD engagement from the dashboard. Over years of service, temperature fluctuations, and exposure to road salt, the large outer vacuum hub O-ring dry-rots or cracks, introducing a persistent vacuum leak that stops your automatic 4WD from functioning. Simultaneously, the outer axle shaft dust seal decomposes, leaving a gap that permits abrasive trail mud, moisture, and road grit to penetrate the axle tubes and wear out your inner axle components.

This original equipment manufacturer (OEM) service kit provides a factory-correct overhaul for one front steering knuckle station. Sourcing genuine Spicer components guarantees exact original manufacturing blueprints are met, offering the precise rubber elasticities and dimensional tolerances required to maintain a persistent airtight vacuum seal under extreme steering deflection.

Kit Contents (Services One Steering Knuckle Side):

• (1) Premium Outer Wheel Hub Vacuum O-Ring (Part # 41766 / 701114)

• (1) Outer Axle Shaft to Tube Dust Boot Seal (Part # 50381)

• (1) Inner Wheel Bearing Hub Assembly Backing Spacer / Seal

Kit Highlights:

• Restores Automatic 4WD Vacuum: Replaces the critical large-diameter outer O-ring to seal your vacuum system, bringing your dashboard Electronic Shift-on-the-Fly (ESOF) automatic hubs back to life.

• Genuine Spicer OEM Engineering: Formulated by the vehicle's original equipment axle supplier to guarantee matching factory rubber durometer ratings and precise dimensional fitment.

• Impenetrable Dust Barrier: The included outer axle shaft seal forms a tight physical shield at the end of the axle tube, keeping out highway water, mud, and abrasive grit.

• Prevents Costly Hub Swaps: Replacing worn-out seals early prevents dirt contamination from chewing through your expensive front wheel bearing hub assemblies.

Vehicle & Axle Fitment:

• Axle Profiles: Open-Knuckle Solid/Monobeam Front Axles: Dana 50 and Dana 60 configurations with vacuum-operated automatic locking hubs.

• Ford Models: 1998, 1999, 2000, 2001, 2002, 2003, and 2004 Ford F-250 Super Duty, F-350 Super Duty, F-450 Super Duty, and F-550 Super Duty 4WD trucks, alongside 2000–2005 Ford Excursion 4x4 vehicles.

• Position: Front Steering Knuckle Wheel Station (Fits Left or Right Side — 2 Kits Required per Vehicle)