FAG SS3123 Transfer Case Output Shaft Seal - Rear

FAG SS3123 Transfer Case Output Shaft Seal

The FAG SS3123 transfer case output shaft seal is built for applications that need a precise sealing fit at the transfer case output. It uses nitrile sealing material with a metal shell, spring, auxiliary lip, and inner shell construction to help maintain a stable seal under drivetrain operating conditions. For drivers searching for a transfer case output shaft seal for vehicle service, this part number is a direct replacement option for select applications.

Key Features

• Part number: SS3123
• Transfer case output shaft seal for drivetrain sealing service
• Nitrile sealing material for oil-resistant sealing performance
• Metal shell with spring, auxiliary lip, and inner shell design
• Bore diameter: 3.371 in. / 85.623 mm
• Seal outside diameter: 3.376 in. / 85.75 mm
• Seal width: 2.125 in. / 9.525 mm
• Cross-references National 413470 and SKF 21352 for the same application

Detailed Description

FAG designs sealing components to meet vehicle manufacturer specifications, and the SS3123 follows that approach with dimensions and materials selected for transfer case service. The nitrile sealing element is paired with a metal-supported structure and spring-loaded sealing profile to help maintain contact at the shaft interface. This makes the FAG SS3123 a practical choice when replacing a worn transfer case output shaft seal on vehicles that require accurate bore and outside diameter matching. If you are servicing a transfer case on a Ford F-150, Chevrolet Silverado, or Jeep Wrangler application that uses this seal specification, confirm dimensions and OE references before installation.

What It Helps Address

• Transfer case fluid seepage at the output shaft
• Contamination entry from dirt, dust, and moisture
• Grease or lubricant loss at the sealing surface
• Noise or driveline concerns caused by low fluid level
• Repeat leaks from a worn or hardened seal

Installation Notes and Tips

Verify bore diameter, seal outside diameter, and seal width against the original part before installation. Inspect the shaft surface for grooves, corrosion, or scoring, since seal performance depends on a clean and uniform contact area. Use proper installation tools to keep the seal square in the bore and avoid damaging the sealing lip. Confirm the transfer case fluid level after service and check for leaks during a road test.

Quality Assurance

FAG manufactures sealing components to meet vehicle-specific specifications and quality standards. The SS3123 is engineered for dimensional accuracy and consistent sealing performance in transfer case applications.