National 714598 Automatic Transmission Oil Pump Seal - Front

Automatic Transmission Oil Pump Seal for GM 4L80-E and 4L85-E

National 714598 is an automatic transmission oil pump seal built for front pump sealing applications in a wide range of GM and specialty vehicles. It uses a polyacrylate sealing material with a clockwise-spiral lip design to help maintain a consistent seal at the pump shaft.

With OE-style dimensions and Redicoat surface treatment, National 714598 is made for service work on vehicles such as Chevrolet Express, GMC Savana, and Silverado models that use the 4L80-E or 4L85-E transmission.

Key Features

• Part number: 714598
• Automatic transmission oil pump seal for front pump applications
• Polyacrylate sealing material for transmission fluid sealing
• Clockwise-spiral lip design
• Redicoat surface treatment
• Inside diameter: 1.998 in. / 50.749 mm
• Outside diameter: 2.882 in. / 73.200 mm
• Thickness: 0.340 in. / 8.640 mm
• Housing bore: 2.878 in. / 73.100 mm
• Flanged outside diameter: 3.165 in. / 80.390 mm

Detailed Description

National 714598 is an oil seal designed for the transmission front pump area, where accurate shaft sealing is critical to maintaining fluid control. The seal’s polyacrylate material and spiral lip profile are specified to match the demands of automatic transmission service, while the listed dimensions help support proper fit in the housing bore and on the shaft.

This part cross-references ATP JO-122 and Gates 19939 for the same application. It is a direct-fit style service part for many Chevrolet Express 2500, Chevrolet Express 3500, GMC Savana 2500, GMC Savana 3500, and related GM truck applications using the 4L80-E or 4L85-E transmission. National has supplied sealing products for more than 75 years, and this part reflects that focus on transmission sealing accuracy.

What It Helps Address

• Transmission fluid leakage at the front pump seal
• Fluid loss caused by worn or hardened seal material
• Seepage around the pump shaft area
• Service replacement during transmission rebuild or overhaul
• Seal wear in high-mileage 4L80-E and 4L85-E applications

Installation Notes and Tips

Verify shaft diameter, housing bore, and seal orientation before installation. The clockwise-spiral lip design must be installed in the correct direction for proper sealing performance. Clean the pump bore and shaft surface thoroughly, and inspect for scoring, burrs, or wear that could affect seal life.

Compatible fitment includes 2000-2009 Chevrolet Express 2500, front; 2000-2009 Chevrolet Express 3500, front; 2000-2009 GMC Savana 2500, front; 2000-2009 GMC Savana 3500, front; and 2001-2007 Chevrolet Silverado 2500 HD, front, among other listed GM and specialty applications.

Quality Assurance

National designs sealing solutions for modern vehicle service needs and backs this part with decades of sealing-system experience. The 714598 oil pump seal is built to the listed dimensional specifications for consistent transmission service in supported applications.