National 710506 Differential Pinion Seal - Rear Outer

National 710506 Differential Pinion Seal

National 710506 is a differential pinion seal built for rear outer applications that demand accurate sealing and stable fitment. It is specified for a wide range of GM trucks and SUVs, including Chevrolet Silverado 1500, Tahoe, GMC Sierra 1500, and Yukon applications with manual transmission input shaft bearing notes in the catalog data.

Key Features

• Part number: 710506
• Part description: oil seal
• Material: nitrile
• Helix type: clockwise-spiral lip design
• Inside diameter: 2.125 in. / 53.980 mm
• Outside diameter: 2.764 in. / 70.200 mm
• Flanged outside diameter: 3.228 in. / 82.000 mm
• Thickness: 0.469 in. / 11.900 mm
• Width: 0.496 in. / 12.600 mm
• Overall width with side lip: 0.535 in. / 13.600 mm
• Housing bore: 2.756 in. / 70.000 mm
• Shaft size: 2.087 in. / 53.000 mm

Detailed Description

National 710506 is part of the 710500 series and is engineered as a precision sealing solution for driveline and axle service. The nitrile construction and clockwise-spiral lip design support controlled sealing at the pinion area, while the listed dimensions help confirm proper housing and shaft match-up during differential repair. This part cross-references Gates 21285 for the same application.

Compatible With 1997-2018 Chevrolet Silverado 1500, Rear Outer; 1998-2000 Chevrolet Tahoe, Rear Outer; and 1999-2018 GMC Sierra 1500, Rear Outer. It also appears in cataloged applications for Cadillac Escalade, GMC Yukon, and Chevrolet Express 1500, making National 710506 a relevant search term for rear differential pinion seal replacement on GM platforms.

Common Issues This Seal Addresses

• Gear oil leakage at the differential pinion area
• Contamination around the rear axle seal surface
• Noise or wear concerns caused by low lubricant level
• Seal replacement during differential service or rebuild
• Fitment verification for rear outer axle sealing applications

Installation Notes and Tips

Confirm the shaft, housing bore, outside diameter, and width against the vehicle before installation. Clean the seal bore and mating surface thoroughly, inspect the pinion yoke and shaft for wear, and verify the seal orientation matches the application. For best results, use the catalog notes to match the exact year, make, model, and rear outer position before installing National 710506.

Quality Assurance

National has supplied sealing products for more than 75 years and continues to develop sealing solutions for modern vehicles. The 710506 differential pinion seal reflects that focus on dimensional accuracy and application-specific design for driveline service.