National 710717 Manual Transmission Input Shaft Seal

Manual Transmission Input Shaft Seal for ZF S6-650

The National 710717 manual transmission input shaft seal is built for metric applications that require a precise seal at the transmission input shaft. It uses a fluoro-elastomer sealing material and a bi-directional lip design to help maintain a consistent seal in demanding drivetrain conditions.

Compatible with Ford F-250 Super Duty and Ford F-350 Super Duty models with the ZF S6-650 transmission, as well as Chevrolet Silverado 2500 HD, Chevrolet Silverado 3500, GMC Sierra 2500 HD, and GMC Sierra 3500 applications with the same transmission.

• Part number: 710717
• Manual transmission input shaft seal / oil seal
• Fluoro-elastomer construction for sealing performance in transmission service
• Bi-directional lip design
• Metric dimensions for accurate housing and shaft fit
• Inside diameter: 1.575 in. / 40.000 mm
• Outside diameter: 2.173 in. / 55.200 mm
• Width: 0.289 in. / 7.330 mm
• Housing bore: 2.165 in. / 55.000 mm

Detailed Product Information

National 710717 is part of the 710700 series and is engineered as a metric oil seal for the transmission input shaft. The seal measures 40.000 mm inside diameter, 55.200 mm outside diameter, and 7.330 mm width, making it a direct-specification service part for the listed manual transmission applications. National has supplied sealing solutions for decades, and this seal reflects that focus on dimensional accuracy and drivetrain sealing performance.

This part cross-references Dorman - HELP 15818 for the same application.

Common Replacement Uses

• Transmission fluid seepage at the input shaft area
• Oil contamination around the bellhousing or transmission front section
• Seal wear from age, heat, or mileage
• Service replacement during manual transmission repair
• Restoring sealing integrity on ZF S6-650-equipped trucks

Installation Notes and Tips

Confirm the transmission model and housing bore before installation, and verify shaft dimensions against the seal specifications. Clean the sealing surface thoroughly, inspect the shaft for wear or scoring, and install the seal squarely to avoid lip damage. For Ford F-250 Super Duty, Ford F-350 Super Duty, Chevrolet Silverado 2500 HD, Chevrolet Silverado 3500, GMC Sierra 2500 HD, and GMC Sierra 3500 applications, match the seal to the ZF S6-650 transmission configuration before service.

Quality Assurance

National is known for premium sealing solutions and long-standing industry experience in drivetrain sealing products. Part number 710717 is manufactured to support accurate fitment and dependable sealing performance in the specified manual transmission applications.