National 8940S Wheel Seal - Rear

National 8940S Wheel Seal for Rear Axles

The National 8940S wheel seal is a rear axle sealing solution built for select Buick, Oldsmobile, and Pontiac applications. It uses nitrile construction and precise dimensional sizing to help maintain a proper seal at the shaft and housing bore.

• Part number: 8940S
• Wheel seal / oil seal design for driveline and axle sealing
• Nitrile material for sealing performance in automotive service
• Inside diameter: 1.523 in. / 38.680 mm
• Outside diameter: 2.718 in. / 69.040 mm
• Housing bore: 2.714 in. / 68.940 mm
• Width: 0.500 in. / 12.700 mm
• Series: 8000, Type 48

Fitment Details

Compatible with rear applications on select vehicles, including Fits 1968-1970 Buick LeSabre, Rear; Fits 1965-1970 Oldsmobile 98, Rear; Fits 1965-1970 Oldsmobile Delta 88, Rear; Fits 1965-1970 Pontiac Bonneville, Rear; Fits 1965-1970 Pontiac Catalina, Rear; Fits 1965-1968 Pontiac Grand Prix, Rear; Fits 1967 Buick LeSabre, Rear, 2nd Design; with 0.5 in. width and 2.718 in. outside diameter; and Fits 1965-1966 Oldsmobile Starfire, Rear.

This part cross-references Bosch 15376 and Centric Parts 417.62021 for the same application.

Detailed Description

National has supplied sealing products for more than 75 years, and the 8940S reflects that focus with a dimensionally specific design for rear wheel and axle sealing. The seal’s 1.523-inch shaft diameter, 2.718-inch outside diameter, and 0.500-inch width are important reference points when matching the part to the axle housing and shaft dimensions on the vehicle. For restorations and maintenance on classic Buick LeSabre, Oldsmobile 98 and Delta 88, and Pontiac Bonneville, Catalina, or Grand Prix models, accurate seal sizing helps support proper fitment at the rear axle.

Common Issues This Seal Addresses

• Rear axle oil seepage at the wheel seal area
• Contamination entering the axle housing through a worn seal
• Seal wear from age, heat, and mileage
• Improper sealing caused by incorrect shaft or housing bore dimensions
• Noise or service concerns related to degraded axle sealing surfaces

Installation Notes and Tips

Verify shaft diameter, housing bore, and seal width before installation to confirm the 8940S matches the axle assembly. Inspect the sealing surface for wear, scoring, or corrosion, and clean the housing thoroughly before pressing in the new seal. On the 1967 Buick LeSabre 2nd Design application, confirm the 0.5-inch width and 2.718-inch outside diameter noted in the fitment data.

Quality Assurance

National is recognized for premium sealing solutions and ongoing product development for modern and classic vehicle service. The 8940S is part of the National 8000 series and is engineered to meet the dimensional requirements listed for the specified rear axle applications.