National 713771 Manual Transmission Input Shaft Seal - Front

Manual Transmission Input Shaft Seal for OE-Style Service

National 713771 is a manual transmission input shaft seal built for metric applications that require a precise sealing fit. It uses a fluoro-elastomer sealing material and a clockwise-spiral lip design to help maintain a tight seal at the transmission input shaft.

With a 35.000 mm inside diameter, 50.340 mm outside diameter, and 7.000 mm width, this oil seal is sized for specific manual transmission housings and shafts. National 713771 is a direct-fit sealing solution for select Ford F-150, Ford F-250, Ford F-350, Acura RL, and Honda Accord applications, along with other listed vehicles.

Key Features

• Manual transmission input shaft seal for transmission sealing service
• Fluoro-elastomer material for sealing performance in demanding drivetrain conditions
• Clockwise-spiral lip design
• Metric dimensions: 35.000 mm shaft diameter, 50.340 mm outside diameter, 7.000 mm width
• Housing bore: 50.000 mm
• Oil seal construction for transmission gasket and sealing system repairs
• National 713771 part number for accurate ordering and lookup

Detailed Description

National 713771 is part of the 713000 series and is engineered as a manual transmission input shaft seal for select vehicles with matching shaft and housing dimensions. The fluoro-elastomer sealing material is selected for durability in transmission environments, while the spiral lip design supports consistent sealing at the input shaft. This seal is listed for a wide range of applications, including 1999-2005 Ford F-350 Super Duty with ZF S5-47 transmission, 1988-1996 Ford F-150 with ZF S5-42 transmission, 1996-2004 Acura RL, and 1995-1997 Honda Accord.

National has supplied sealing products for more than 75 years, and this part reflects that focus on precision-fit transmission sealing. If you are servicing a manual gearbox leak or replacing a worn input shaft seal, National 713771 provides the dimensional match needed for the listed applications. This part cross-references Dorman - HELP 13716 for the same application.

What It Helps Address

• Transmission fluid seepage at the input shaft
• Oil leakage from a worn or hardened seal lip
• Contamination entering the transmission through a failed seal
• Service issues during manual transmission rebuilds or clutch-related repairs
• Fitment problems when replacing an OE-style input shaft seal on listed Ford, Acura, Honda, and Mazda vehicles

Installation Notes and Tips

Verify shaft diameter, housing bore, and transmission code before installation. National 713771 is specified for metric dimensions, so confirm the 35.000 mm shaft and 50.000 mm housing bore match the vehicle and transmission being serviced. Clean the bore and shaft surface thoroughly, inspect for scoring or wear, and install the seal squarely to avoid lip damage. For best results, confirm the application against the exact year, make, model, and transmission notes listed for Ford F-150, Ford F-250, Ford F-350, Acura TL, Acura Legend, and related vehicles.

Quality Assurance

National is a long-established sealing brand with more than 75 years of experience in premium sealing solutions. The 713771 manual transmission input shaft seal is built to the brand’s dimensional and material standards for service on the listed applications.