FAG SS3947 Transfer Case Input Shaft Seal

Transfer Case Input Shaft Seal for Jeep

The FAG SS3947 transfer case input shaft seal is built for Jeep driveline service where sealing accuracy matters. It uses a nitrile sealing material with a metal, spring, and inner shell design to help maintain a tight seal at the transfer case input shaft.

Compatible with select 1963-1979 Jeep Cherokee, CJ5, CJ7, J10, J20, and Wagoneer applications, this seal is sized for specific transfer case service needs and is identified by part number SS3947.

Key Features

• Part number: SS3947
• Transfer case input shaft seal for Jeep driveline applications
• Nitrile sealing material
• Metal, spring, and inner shell seal construction
• Bore diameter: 2 in. (50.8 mm)
• Seal outside diameter: 2.004 in. (50.902 mm)
• Seal width: 1.375 in. (34.925 mm)
• Cross-references National 5872S and SKF 13571

Detailed Description

FAG SS3947 is a transfer case input shaft seal engineered to match specific dimensional requirements for Jeep transfer case service. The nitrile sealing element is paired with a metal, spring, and inner shell design to support consistent sealing at the shaft interface, helping keep lubricant where it belongs and limiting contamination at the transfer case opening. This part is listed for 1963-1979 Jeep Wagoneer, 1974-1979 Jeep Cherokee, 1974-1979 Jeep CJ5, 1976-1979 Jeep CJ7, 1974-1979 Jeep J10, and 1974-1979 Jeep J20 applications. The SS3947 part number is also referenced by National 5872S and SKF 13571 for the same application.

What This Seal Helps Address

• Gear oil leakage at the transfer case input shaft
• Dirt, dust, and moisture intrusion at the seal area
• Loss of lubricant from worn or damaged sealing surfaces
• Service issues on Jeep transfer case rebuilds and repairs
• Replacement needs for aging factory-style seals on classic Jeep drivetrains

Installation Notes and Tips

Verify bore diameter, outside diameter, and seal width before installation to confirm the seal matches the transfer case housing and shaft dimensions. Inspect the shaft surface for grooves, corrosion, or wear that could affect sealing performance. Clean the sealing bore thoroughly and install the seal squarely to avoid distortion. Confirm the application against the vehicle’s transfer case configuration before ordering, especially on classic Jeep models where drivetrain variations may exist.

Quality Assurance

FAG designs seals using high-quality materials and application-specific specifications to meet vehicle manufacturer requirements. This seal is built to support the sealing demands of transfer case service on Jeep Cherokee, CJ5, CJ7, J10, J20, and Wagoneer models.