National A-45 Differential Pinion Bearing - Rear Inner

Overview of National A-45 Differential Pinion Bearing

The National A-45 differential pinion bearing is engineered for reliable driveline performance in select Nissan and INFINITI vehicles. Designed as a taper bearing assembly, this part ensures smooth operation of the differential pinion shaft, critical for maintaining proper axle function.

• Compatible with Nissan 240SX, 300ZX, J30, M30, and INFINITI Q45 models
• Part number A-45 for precise identification and fitment
• Taper bearing assembly with a bore diameter of 1.3780 inches (35 mm)
• Cone length and width of 1.4961 inches (38 mm) for optimal load distribution
• Outside diameter measures 3.5039 inches (89 mm) ensuring proper seating in differential housing

Technical Specifications and Design Details

The National A-45 differential pinion bearing features a bore size of 1.3780 inches (35 mm), accommodating the pinion shaft diameter for a secure fit. The cone length and width are both 1.4961 inches (38 mm), providing a robust contact surface to handle axial and radial loads. The cone radius is 0.0433 inches (1.1 mm), while the cup radius measures 0.0591 inches (1.5 mm), contributing to the bearing’s tapered design that supports smooth rotation and reduces wear. The cup length is 1.0827 inches (27.5 mm), ensuring proper engagement within the differential assembly. This bearing is part of the A40 series and classified as type Ts, indicating its specific design parameters within National’s product range.

Applications and Problem Solving

This differential pinion bearing is intended for use in the driveline and axle assemblies of Nissan and INFINITI vehicles, specifically models 240SX, 300ZX, J30, M30, and Q45. It addresses several common issues:

• Reduces differential noise caused by worn or damaged pinion bearings
• Prevents excessive play in the pinion shaft, improving gear mesh accuracy
• Minimizes vibration and harshness in the driveline system
• Supports proper alignment of the differential gears to extend component life
• Helps maintain smooth torque transfer under varying load conditions

Installation Notes and Tips

When installing the National A-45 differential pinion bearing, ensure the bearing surfaces are clean and free of debris. Proper lubrication is essential to prevent premature wear. Use appropriate tools to press the bearing into place without damaging the cone or cup components. Note that the bearing is supplied as a complete taper bearing assembly; individual components are not available separately. Verify fitment with the vehicle’s service manual to confirm compatibility with Nissan 240SX, 300ZX, J30, M30, and INFINITI Q45 models.

Quality Assurance and Warranty

National bearings are manufactured to meet industry standards for durability and performance. The A-45 differential pinion bearing undergoes rigorous quality control to ensure dimensional accuracy and material integrity. While specific warranty details may vary, National typically offers coverage against manufacturing defects, providing confidence in the part’s reliability for driveline applications.