FAG SS4978 Manual Transmission Seal - Rear

Manual Transmission Seal for Select Isuzu and GM Applications

FAG SS4978 is a manual transmission seal built for specific rear and non-positioned applications across select Isuzu, Chevrolet, and GMC vehicles. It uses a metal spring design with an auxiliary lip and polyacrylate sealing material to help maintain a tight seal at the transmission opening.

Use FAG SS4978 when you need a precise replacement seal for vehicles such as the Isuzu Pickup, Chevrolet LUV, and GMC Jimmy. The part number SS4978 is also referenced in interchange listings for related aftermarket and OE-style applications.

Key Features

• Manual transmission seal for transmission sealing system service
• Seal type: metal, spring, auxiliary lip
• Sealing material: polyacrylate
• Bore diameter: 1.937 in. / 49.2 mm
• Seal outside diameter: 1.944 in. / 49.378 mm
• Seal width: 1.496 in. / 37.998 mm
• FAG part number SS4978 for catalog and service matching

Detailed Description

FAG SS4978 is engineered for transmission sealing applications where dimensional accuracy and material selection matter. The seal’s metal-and-spring construction with an auxiliary lip is designed to maintain contact at the sealing surface, while the polyacrylate sealing material is selected for durability in drivetrain service. With a 1.937-inch bore diameter, 1.944-inch outside diameter, and 1.496-inch width, this seal is specified for exact-fit replacement use on listed vehicles.

Compatible With 1985-1989 Isuzu Impulse, rear; 1981-1987 Isuzu Pickup; 1986-1987 Isuzu Pickup, rear; 1979-1982 Chevrolet LUV; 1979-1982 Chevrolet LUV, rear; 1982 Chevrolet S10; 1982 Chevrolet S10, rear; 1979-1982 GMC Jimmy; 1979-1982 GMC Jimmy, rear; 1982 GMC S15; and 1982 GMC S15, rear. FAG SS4978 also cross-references National 1987 and Timken 1987S for the same application.

What This Seal Helps Address

• Transmission fluid leakage at the seal interface
• Contamination from dirt, dust, and moisture entering the sealed area
• Wear from a hardened or damaged original seal
• Loss of grease or lubricant retention at the bearing or seal area
• Service issues caused by incorrect seal dimensions

Installation Notes and Tips

Verify bore diameter, outside diameter, and width before installation to confirm the seal matches the transmission housing and shaft dimensions. Inspect the sealing surface for scoring, corrosion, or wear before fitting the new seal. Clean the bore thoroughly and install the seal squarely to avoid distortion of the metal case or sealing lip. Confirm the vehicle application by year, make, model, and position before ordering.

Quality Assurance

FAG sources seals to meet vehicle manufacturer specifications and works with suppliers to maintain its quality standards. This seal is built for demanding wheel-end and drivetrain sealing requirements, with application-specific sizing for listed vehicles.