National 710431 Manual Transmission Output Shaft Seal

Manual Transmission Output Shaft Seal for Mustang

The National 710431 manual transmission output shaft seal is built for Ford Mustang applications that use a Tremec or Borg-Warner manual transmission. It uses nitrile construction and a bi-directional lip design to help retain transmission fluid at the output shaft.

• Manual transmission output shaft seal / oil seal
• Nitrile material for sealing performance
• Bi-directional lip design
• Inside diameter: 1.684 in. / 42.780 mm
• Outside diameter: 2.504 in. / 63.600 mm
• Width: 0.433 in. / 11.000 mm
• Housing bore: 2.499 in. / 63.480 mm
• Series 710400

Application Details

National 710431 is a direct-fit oil seal for manual transmission service on Ford Mustang models with the specified transmission types. Fits 2005-2010 Ford Mustang, N/A, with Tremec 3150 Transmission; Fits 2001-2004 Ford Mustang, N/A, with Tremec 3650 Transmission; Fits 1998-2004 Ford Mustang, N/A, with Tremec T45 Transmission; Fits 1996-1997 Ford Mustang, N/A, with Borg-Warner T45 Transmission. This part cross-references Four Seasons 16926 for the same application.

What This Seal Helps Address

• Transmission fluid seepage at the output shaft
• Oil leakage around the rear of the manual transmission
• Contamination from worn or hardened sealing lips
• Service replacement for a damaged output shaft seal
• Fitment-specific repair on Ford Mustang manual transmissions

Installation Notes

Verify transmission type before installation, since fitment varies by Tremec 3150, Tremec 3650, Tremec T45, and Borg-Warner T45 applications. Inspect the shaft surface and housing bore for wear, scoring, or debris before installing the new seal. Proper seating depth and clean mating surfaces are important for reliable sealing performance.

Quality Assurance

National has supplied sealing products for more than 75 years and continues to develop sealing solutions for modern vehicle applications. The 710431 reflects that experience in a manual transmission output shaft seal for Ford Mustang service.