National 710685 Drive Axle Shaft Seal - Front Outer

Overview of National 710685 Drive Axle Shaft Seal

The National 710685 drive axle shaft seal is engineered for reliable sealing performance in Ford Excursion, F-250 Super Duty, and F-350 Super Duty models. Constructed from durable nitrile material, this oil seal is designed to maintain axle integrity and prevent fluid leaks under demanding conditions.

• Material: High-quality nitrile for resistance to oil and wear
• Inside Diameter: 3.528 inches (89.610 mm)
• Outside Diameter: Approximately 5.47 inches (139.0 mm)
• Thickness/Width: 0.654 inches (16.610 mm)
• Compatible with Ford Excursion, F-250 Super Duty, and F-350 Super Duty
• Part Number: 710685, Series 710600

Technical Specifications and Design Details

This drive axle shaft seal features precise dimensions to ensure a proper fit within the axle housing bore, which measures approximately 5.465 inches (138.8 mm). The seal’s inside diameter of 3.528 inches (89.610 mm) closely matches the shaft diameter of 3.545 inches (90.05 mm), providing an effective barrier against oil leakage. The nitrile material offers resistance to heat, oil, and abrasion, making it suitable for heavy-duty applications in Ford Super Duty trucks and Excursion SUVs.

Applications and Problem Solving

This National 710685 seal is specifically designed for use in the driveline and axle assemblies of Ford Excursion, F-250 Super Duty, and F-350 Super Duty vehicles. It addresses common issues such as:

• Preventing oil leaks from the drive axle shaft
• Reducing contamination ingress into the axle housing
• Maintaining proper lubrication of axle components
• Minimizing wear on axle shafts and bearings
• Ensuring consistent driveline performance under load

Installation Notes and Tips

When installing the National 710685 drive axle shaft seal, ensure the axle shaft and housing bore are clean and free of debris. Use appropriate tools to press the seal evenly into the housing bore without distortion. Verify the seal’s orientation matches the original part to maintain proper sealing function. Lubricate the seal lip lightly with clean axle oil before installation to reduce initial wear.

Quality Assurance and Warranty

National parts are manufactured to meet OEM specifications for fit and function. The 710685 drive axle shaft seal undergoes quality control checks to ensure dimensional accuracy and material integrity. While specific warranty details may vary, National typically offers coverage against manufacturing defects to support reliable service life in Ford Excursion, F-250 Super Duty, and F-350 Super Duty applications.