FAG SS3147 Differential Pinion Seal - Rear

FAG SS3147 Differential Pinion Seal

FAG SS3147 is a rear differential pinion seal built for heavy-duty GM truck and van applications that use a 10.50" ring gear. It is engineered with a nitrile sealing material and a metal spring design with an auxiliary lip to help retain lubricant and block contamination at the pinion area.

Use this FAG differential pinion seal when servicing rear axle leaks on Chevrolet and GMC platforms such as C3500, K3500, P3500, and Express 3500 models. The SS3147 part number is also referenced in OE-style replacement searches for older GM rear axle service work.

Key Features

• Rear differential pinion seal for GM driveline service
• Seal type: metal, spring, and auxiliary lip
• Nitrile sealing material for oil resistance in axle applications
• Designed for 10.50" ring gear rear axle setups
• Fits a wide range of Chevrolet and GMC rear applications from 1973-2000
• Part number: SS3147

Detailed Description

FAG SS3147 is specified for rear axle pinion sealing on many Chevrolet and GMC trucks, vans, and Suburban models. Confirmed applications include rear fitment for Chevrolet C3500, K3500, Express 2500, Express 3500, GMC C3500, K3500, P3500, Savana 2500, and Savana 3500, along with numerous C/K, R/V, P-series, and G-series vehicles across the 1973-2000 model years. This part cross-references Gates 21955 for the same application.

The seal construction uses a metal case, spring tension, and auxiliary lip to help maintain sealing contact at the pinion shaft. FAG specifies high-quality materials and application-specific design standards to meet demanding wheel-end and axle sealing requirements. The SS3147 part number is commonly searched for rear differential pinion seal replacement on Chevrolet and GMC 10.50" ring gear axles.

What It Helps Fix

• Rear differential gear oil leaking from the pinion area
• Contamination entering the axle housing through a worn seal
• Lubricant loss around the pinion shaft seal surface
• Noise or wear concerns caused by low differential fluid level
• Service issues on GM rear axles with a 10.50" ring gear

Installation Notes and Tips

Verify axle design, ring gear size, and rear position before ordering. This seal is listed for specific Chevrolet and GMC rear axle configurations, including 1st and 2nd design variants on certain models. Inspect the pinion yoke and sealing surface for wear, scoring, or corrosion before installation, and replace damaged components as needed to restore proper sealing.

For fitment-based searches, this part fits 1988-2000 GMC C3500, rear; fits 1989-1999 Chevrolet C35, rear; and fits 1996-1997 Chevrolet Express 3500, rear. It also fits 1989-1997 GMC K3500, rear and 1988-1997 Chevrolet K2500, rear in the listed axle configurations.

Quality Assurance

FAG designs seals using manufacturer-specific specifications and works with suppliers to maintain its quality standards. The SS3147 is built for demanding axle sealing service where contamination control and lubricant retention are critical.