National 710549 Differential Pinion Seal - Front Outer

National 710549 Differential Pinion Seal

The National 710549 differential pinion seal is built for front outer axle applications that need a precise sealing surface and stable fit. It is a direct replacement oil seal for select Chevrolet Colorado, GMC Canyon, Hummer H3, H3T, and Isuzu i-350/i-370 models with AAM axle and 7.6-inch ring gear configurations.

• Part number: 710549
• Part description: oil seal
• Inside diameter: 1.682 in. / 42.970 mm
• Outside diameter: 2.668 in. / 67.770 mm
• Flanged outside diameter: 3.110 in. / 78.990 mm
• Thickness/width: 0.383 in. / 9.730 mm
• Housing bore: 2.660 in. / 67.570 mm
• Fluoro-elastomer material for sealing performance
• Counter-clockwise spiral lip design
• National 710500 series

Fitment Details

Compatible With select front outer differential pinion applications, including Fits 2004-2013 Chevrolet Colorado, Front Outer; Fits 2004-2012 GMC Canyon, Front Outer; Fits 2006-2010 Hummer H3, Front Outer; Fits 2009-2010 Hummer H3T, Front Outer; Fits 2007-2008 Isuzu i-370, Front Outer; and Fits 2006 Isuzu i-350, Front Outer. These applications use a 7.6-inch ring gear with AAM axle and independent carrier unit notes.

Detailed Description

National 710549 is a differential pinion seal engineered around the listed shaft and housing dimensions to help maintain a tight seal at the front outer position. The fluoro-elastomer construction and counter-clockwise spiral lip design support sealing at the pinion area where differential fluid retention is critical. National has supplied sealing solutions for more than 75 years, and this seal reflects that focus on dimensional accuracy and modern driveline service needs. This part cross-references Gates 26510 for the same application.

Common Replacement Reasons

• Differential gear oil leaking from the front outer pinion area
• Wet residue around the pinion seal or axle housing
• Noise or contamination caused by low differential fluid level
• Seal wear from age, heat, or driveline movement
• Service replacement during axle or differential maintenance

Installation Notes and Tips

Verify the shaft, housing bore, and flange dimensions before installation. Clean the sealing surface thoroughly and inspect the pinion yoke and surrounding components for wear or scoring that could affect seal life. Confirm the vehicle uses the listed front outer configuration with a 7.6-inch ring gear and AAM axle before ordering. National 710549 is a direct-fit style replacement for the specified applications, including Chevrolet Colorado and GMC Canyon front outer differential service.

Quality Assurance

National is a long-established sealing brand with a reputation built on premium sealing solutions and ongoing product development for current vehicle platforms. Part number 710549 is manufactured to support the dimensional and material requirements of the listed driveline applications.