National 714679 Automatic Transmission Output Shaft Seal - Left

Automatic Transmission Output Shaft Seal

National 714679 is an automatic transmission output shaft seal built for applications using the GMC 4T80-E transmission. It is a polyacrylate oil seal with a bi-directional lip design and Redicoat coating for a precise sealing surface. This seal is listed for left-side fitment on select Buick, Cadillac, Oldsmobile, and Pontiac vehicles.

Key Features

• Automatic transmission output shaft seal for transmission sealing service
• Polyacrylate construction for durability in transmission environments
• Bi-directional lip design for sealing performance in either rotational direction
• Redicoat finish for improved installation and sealing contact
• Dimensions: 1.605 in. shaft ID, 2.565 in. OD, 0.369 in. width
• Housing bore: 2.560 in. for proper fitment in the transmission case
• National 714679, series 714000

Detailed Description

National 714679 is an oil seal engineered for the output shaft area of automatic transmissions. Its 1.605-inch inside diameter, 2.565-inch outside diameter, and 0.369-inch thickness help support a correct seal interface, while the bi-directional lip design is suited to transmission operation. This part is listed for left-side applications on 1993-2011 Buick Lucerne, Cadillac DTS, Cadillac DeVille, Cadillac Seville, Cadillac Eldorado, Cadillac Allante, Oldsmobile Aurora, and Pontiac Bonneville models equipped with the GMC 4T80-E transmission. This part cross-references SKF 16295 for the same application.

Common Uses

• Transmission fluid leakage at the output shaft seal area
• Seal wear from age, heat, or fluid exposure
• Service replacement during transmission repair or rebuild
• Restoring proper sealing on 4T80-E-equipped Buick, Cadillac, Oldsmobile, and Pontiac vehicles

Installation Notes

Verify shaft diameter, housing bore, and transmission application before installation. Clean the seal bore and shaft surface thoroughly, and inspect for scoring or wear that could affect sealing. Use care during installation to avoid damaging the lip or coating, and confirm the seal seats evenly in the bore.

Quality Assurance

National has supplied sealing products for more than 75 years and continues to develop sealing solutions for modern vehicle applications. National 714679 is built as a precision transmission seal for the listed fitments and dimensions.