National 711078 Drive Axle Shaft Seal - Rear

Overview of National 711078 Drive Axle Shaft Seal

The National 711078 drive axle shaft seal is engineered for reliable sealing performance in driveline applications. Designed with a bi-directional lip helix and constructed from durable polyacrylate material, this oil seal is compatible with select Chrysler, Dodge, and Mercedes-Benz models.

• Material: Polyacrylate for enhanced durability and resistance
• Flanged Outside Diameter: 4.961 inches (126 mm)
• Housing Bore Diameter: 4.028 inches (102.3 mm)
• Outside Diameter: 4.039 inches (102.6 mm)
• Overall Width with Side Lip: 0.720 inches (18.3 mm)
• Shaft Diameter: 1.771 inches (45 mm)
• Bi-directional lip design for effective sealing in both rotational directions
• Part Number: 711078, Series 711000

Technical Description and Specifications

The National 711078 drive axle shaft seal is part of the 711000 series, designed to provide a secure seal around the axle shaft to prevent oil leakage and contamination ingress. Its polyacrylate construction offers chemical resistance and flexibility, maintaining a tight seal under varying temperature and pressure conditions. The bi-directional helix lip design ensures effective sealing regardless of shaft rotation direction, which is critical for driveline components subjected to dynamic forces.

With a flanged outside diameter of 4.961 inches (126 mm) and a housing bore diameter of 4.028 inches (102.3 mm), this seal fits precisely in the axle housing. The shaft diameter of 1.771 inches (45 mm) and overall width of 0.453 inches (11.5 mm) provide a compact yet robust sealing solution. The side lip width of 0.720 inches (18.3 mm) adds an additional barrier against fluid leakage.

Compatible Vehicles and Applications

This drive axle shaft seal is compatible with various Chrysler, Dodge, and Mercedes-Benz models, including the Chrysler 300, Dodge Challenger, Dodge Charger, Dodge Magnum, Mercedes-Benz C320, CL500, CL600, S430, and S500. It is designed specifically for driveline and axle sealing systems where precise fitment and reliable sealing are required.

Common Issues Addressed by the National 711078 Seal

• Prevents oil leaks from the drive axle shaft area
• Protects axle bearings and components from dirt and contaminants
• Reduces risk of driveline component wear due to fluid loss
• Maintains proper lubrication within the axle housing
• Helps avoid costly repairs related to seal failure

Installation Notes and Tips

• Ensure the housing bore and shaft surfaces are clean and free of debris before installation
• Use appropriate tools to press the seal evenly into the housing bore without distortion
• Verify the seal orientation matches the bi-directional lip design for optimal performance
• Inspect the shaft for wear or damage that could compromise the seal
• Apply a light coating of compatible lubricant on the seal lip before installation

Quality Assurance and Warranty

National drive axle shaft seals are manufactured to meet industry standards for durability and performance. The 711078 seal undergoes rigorous quality control to ensure dimensional accuracy and material integrity. While specific warranty terms may vary, National typically offers coverage against manufacturing defects to provide confidence in product reliability.