National 394A Wheel Bearing Race - Rear or Rear Inner

National 394A Taper Bearing Cup for Rear Axles

National 394A is a taper bearing cup built for rear driveline and axle service on select Chevrolet and GMC heavy-duty applications. It uses premium-grade steel and a crowned raceway profile to promote even load distribution in the bearing assembly.

Key Features

• Part number: 394A
• Part type: taper bearing cup / wheel bearing race
• Premium-grade steel construction
• Crowned raceway for more even load distribution
• Cup bore: 4.3307 in. (110.0000 mm)
• Cup length: 0.7411 in. (18.8240 mm)
• Cup radius: 0.0460 in. (1.1680 mm)
• Rear position application

Detailed Description

National 394A is a taper bearing cup for rear axle service in vehicles such as the Chevrolet C3500, Chevrolet P30, Chevrolet V3500, Chevrolet V30, GMC C3500, GMC P3500, and GMC V3500 with a 12-inch ring gear and Rockwell C100 axle. The crowned raceway design helps the bearing rollers track more evenly across the cup surface, while the steel construction supports consistent fit and durability in demanding driveline use. This part number 394A is also referenced by multiple aftermarket and OE cross listings, including Schaeffler 394-A.

For buyers searching for a rear wheel bearing race for Chevrolet C3500 Rockwell C100 axle service or a GMC P3500 taper bearing cup replacement, National 394A provides the dimensional and application-specific details needed for a direct-match selection.

What This Part Helps Address

• Excessive bearing wear in the rear axle assembly
• Rough or noisy wheel bearing operation
• Race surface damage during axle rebuilds
• Incorrect bearing cup dimensions during service replacement
• Restoration work on Chevrolet and GMC heavy-duty rear axles

Installation Notes and Tips

Verify the cup bore, length, and radius against the removed part before installation. Confirm rear axle configuration, including the 12-inch ring gear and Rockwell C100 axle note, to ensure the correct application. Press the cup into a clean, properly prepared housing and inspect the mating bearing components for wear or scoring before reassembly.

Quality Assurance

National manufactures this taper bearing cup with premium-grade steel and a crowned raceway profile to support even load distribution in service. The 394A part number is listed across multiple interchange references for the same application, including Schaeffler 394-A.