National 710668 Transfer Case Output Shaft Seal - Front

Overview of National 710668 Transfer Case Output Shaft Seal

The National 710668 transfer case output shaft seal is engineered to provide reliable sealing performance for select GM and Dodge vehicles. Designed with a bi-directional lip and fluoro-elastomer material, this oil seal helps maintain transfer case integrity and prevent fluid leaks.

• Inside diameter options: 1.376 inch (34.95 mm) and 1.378 inch (35.00 mm)
• Outside diameter: 2.567 inch (65.20 mm)
• Thickness: 0.398 inch (10.00 mm)
• Bi-directional lip design for effective sealing in both rotational directions
• Constructed from durable fluoro-elastomer sealing material
• Compatible housing bore: 2.559 inch (65.00 mm)
• Overall width with side lip: 0.650 inch (16.5 mm)

Technical Details and Material Specifications

This transfer case output shaft seal from National is part of the 710600 series and is specifically designed to fit transfer cases requiring a 40-type seal. The fluoro-elastomer material offers resistance to heat, oil, and wear, making it suitable for demanding automotive environments. The bi-directional lip design ensures a tight seal around the shaft, minimizing the risk of fluid leakage during both forward and reverse rotation.

Compatible Vehicles and Applications

The National 710668 seal is compatible with a range of vehicles including Cadillac, Chevrolet, Dodge, GMC, and Oldsmobile models. It is suitable for transfer cases in vehicles such as the Chevrolet Avalanche 1500 and 2500, Silverado 1500 and 1500 Classic, Suburban 1500 and 2500, Tahoe, Yukon and Yukon XL 1500/2500, as well as the GMC Sierra 1500 and 1500 Classic, Jimmy, Bravada, and Safari. Dodge Ram 1500 and other GM trucks like the Blazer and Astro are also supported.

Common Issues Addressed by the 710668 Transfer Case Seal

• Prevents transfer case fluid leaks that can cause damage to internal components
• Reduces contamination ingress into the transfer case assembly
• Maintains proper lubrication by sealing the output shaft effectively
• Helps avoid costly repairs related to seal failure and fluid loss
• Improves transfer case longevity and operational reliability

Installation Notes and Tips

• Ensure the housing bore is clean and free of debris before installation
• Verify shaft dimensions match the seal’s inside diameter for proper fit
• Use appropriate tools to avoid damaging the seal during installation
• Apply a light coating of transfer case fluid on the seal lip to ease installation
• Check for proper seating and alignment to prevent premature wear

Quality Assurance and Warranty Information

National transfer case output shaft seals are manufactured to meet OEM specifications and undergo rigorous quality control testing. The fluoro-elastomer material and bi-directional lip design contribute to consistent sealing performance under various operating conditions. While specific warranty details may vary, National typically offers coverage against manufacturing defects to ensure customer confidence in product reliability.