National 387AS Axle Differential Bearing - Front Inner, Rear or Rear Inner

Overview of National 387AS Axle Differential Bearing

The National 387AS axle differential bearing is engineered for reliable driveline performance in a variety of vehicles including Chevrolet, Dodge, Ford, GMC, Mercedes-Benz, and Ram models. This taper bearing cone is designed to meet precise specifications, ensuring proper fit and function in axle differentials.

• Brand: National
• Part Number: 387AS
• Category: Driveline and Axles > Bearings
• Part Type: Axle Differential Bearing (Taper Bearing Cone)
• Cone Bore Diameter: 2.2500 inches (57.15 mm)
• Cone Length: 0.8640 inches (21.946 mm)
• Cone Radius: 0.2030 inches (5.156 mm)

Technical Specifications and Design Details

The National 387AS bearing cone features a cone bore diameter of 2.2500 inches (57.15 mm), which is critical for proper seating on the axle shaft. Its cone length measures 0.8640 inches (21.946 mm), providing the necessary surface area for load distribution within the differential assembly. The cone radius of 0.2030 inches (5.156 mm) supports smooth rotation and reduces friction during operation. This taper bearing cone is manufactured to meet OEM standards, ensuring compatibility and durability across multiple vehicle platforms.

Compatible Vehicles and Applications

This axle differential bearing is compatible with a wide range of vehicles, including Chevrolet Silverado 2500 HD, GMC Sierra 2500, Ford F-250 Super Duty, Dodge Ram 1500, and Mercedes-Benz 300SD models. It is suitable for use in axle differentials of trucks, SUVs, and passenger cars such as the Chevrolet Avalanche 2500, Ford E-350 Econoline, and Mercedes-Benz CL500. The National 387AS bearing supports driveline components in both light and heavy-duty applications.

Common Issues Addressed by National 387AS Bearing

• Eliminates excessive play or looseness in the axle differential
• Reduces noise and vibration caused by worn or damaged bearings
• Prevents premature wear of axle shafts and differential gears
• Restores smooth rotation and proper alignment within the differential
• Improves overall driveline reliability and performance

Installation Notes and Tips

Proper installation of the National 387AS axle differential bearing requires careful cleaning of the bearing seat and axle shaft. Use appropriate tools to press the bearing cone onto the axle shaft without causing damage. Verify the cone bore and length dimensions to ensure correct fitment. It is recommended to inspect related components such as races and seals during installation to maintain optimal driveline function.

Quality Assurance and Warranty Information

National bearings are manufactured to meet stringent quality standards, providing consistent performance and durability. The 387AS axle differential bearing undergoes rigorous testing to ensure dimensional accuracy and material integrity. While specific warranty details may vary, National typically offers coverage against manufacturing defects to support long-term reliability in automotive applications.