National 710687 Axle Output Shaft Seal - Front Left

Axle Output Shaft Seal for Front Left Applications

National 710687 is an axle output shaft seal built for front left driveline service on a wide range of GM and related vehicles with AAM differential and independent front suspension setups. It uses a polyacrylate sealing material and a bi-directional lip design to help maintain a consistent seal at the shaft interface.

Compatible With 1995-2014 Chevrolet Astro, Blazer, S10, Trailblazer, Express 1500, Express 2500, Trailblazer EXT; 1995-2014 GMC Jimmy, Safari, Sonoma, Envoy, Envoy XL, Envoy XUV, Savana 1500, Savana 2500; and select Buick, Isuzu, Oldsmobile, and Saab front left applications. National 710687 is also referenced by Quality-Built 15618 for the same application.

Key Features

• Axle output shaft seal / oil seal for driveline and axle sealing service
• Polyacrylate material for sealing performance in demanding drivetrain environments
• Bi-directional lip design for sealing action in either rotational direction
• Metric dimensions: 40.000 mm shaft inside diameter, 75.100 mm outside diameter, 15.000 mm width
• Housing bore: 75.000 mm; overall width with side lip: 20.400 mm
• National part number 710687 for direct identification and ordering

Detailed Description

National 710687 is an axle output shaft seal designed around metric dimensions and a precise housing fit. The seal measures 40.000 mm inside diameter, 75.100 mm outside diameter, and 15.000 mm width, with a 75.000 mm housing bore and 20.400 mm overall width including the side lip. Its bi-directional lip design supports sealing at the axle output shaft where consistent fluid retention is critical.

This seal is used in front left applications on vehicles such as the Chevrolet Trailblazer, GMC Envoy, and Chevrolet S10, along with other listed Chevrolet, GMC, Buick, Isuzu, Oldsmobile, and Saab models. National 710687 is part of the 710600 series and reflects National’s long-running focus on sealing solutions for modern driveline systems.

Common Problems This Seal Can Address

• Gear oil seepage at the axle output shaft
• Contamination entering the differential area through a worn seal
• Fluid loss caused by hardened or damaged sealing lips
• Noise or driveline wear associated with low lubricant level
• Leak recurrence after seal deterioration in front left axle service

Installation Notes and Tips

Verify shaft diameter, housing bore, and application notes before installation. This seal is specified for front left positions with 7.25 in ring gear, AAM differential, and independent front suspension on the listed vehicles. Inspect the shaft surface and seal bore for scoring, corrosion, or debris before pressing the new seal into place. Clean the sealing area thoroughly and confirm the seal seats evenly to avoid premature leakage.

Quality Assurance

National has supplied sealing products for more than 75 years and continues to develop sealing solutions for current vehicle platforms. Part number 710687 is built to the listed metric dimensions and application requirements for dependable axle output shaft sealing.