National 6818 Differential Pinion Seal - Front Outer or Rear Outer

Overview of National 6818 Differential Pinion Seal

The National 6818 differential pinion seal is designed to provide reliable sealing performance for driveline applications. Engineered with nitrile material, this oil seal is compatible with select Chevrolet and Pontiac models, including the Bel Air, Corvette, El Camino, Impala, and Laurentian.

• Inside diameter: 1.739 inches (44.170 mm)
• Outside diameter: 3.008 inches (76.400 mm)
• Thickness/width: 0.500 inches (12.700 mm)
• Material: durable nitrile for oil resistance
• Series: 6000, Type 71 design
• Compatible with housing bore of 3.000 inches (76.200 mm)

Technical Details and Specifications

The National 6818 differential pinion seal features precise dimensions to ensure a proper fit and effective sealing in the differential assembly. The seal’s inside diameter of 1.739 inches matches the shaft size, while the outside diameter of 3.008 inches fits securely within the housing bore of 3.000 inches. Constructed from nitrile, the seal offers resistance to oil and heat, maintaining integrity under typical driveline operating conditions. The 0.500-inch thickness provides adequate sealing surface area to prevent leaks and contamination.

Compatible Vehicles and Applications

This differential pinion seal is compatible with various Chevrolet and Pontiac vehicles, specifically the Bel Air, Corvette, El Camino, Impala, and Laurentian models. It is designed for use in driveline and axle assemblies where a reliable oil seal is required to maintain differential fluid containment and protect internal components.

• Prevents oil leaks in differential pinion shafts
• Protects against dirt and debris intrusion
• Maintains proper lubrication within the differential
• Reduces wear on differential components
• Helps avoid costly drivetrain repairs due to seal failure

Installation Notes and Tips

When installing the National 6818 differential pinion seal, ensure the housing bore and shaft are clean and free of debris. Use appropriate tools to press the seal evenly into the housing bore without damaging the sealing lip. Verify the seal orientation matches the original part to maintain proper oil retention. Lubricate the seal lip lightly with differential fluid before installation to reduce initial wear.

Quality Assurance and Warranty

National manufactures the 6818 differential pinion seal to meet industry standards for durability and performance. The nitrile material and precise dimensions contribute to consistent sealing reliability. While specific warranty details may vary, National products typically come with a limited warranty against manufacturing defects, ensuring confidence in the part’s quality and fitment.