National 710540 Automatic Transmission Output Shaft Seal

Automatic Transmission Output Shaft Seal for Ford

National 710540 is an automatic transmission output shaft seal built for metric applications that require a precise shaft-to-housing seal. It uses a bi-directional lip design and polyacrylate material to help maintain sealing performance in Ford 4F27E transmission applications.

Key Features

• Automatic transmission output shaft seal / oil seal
• Part number: 710540
• Bi-directional lip design for sealing in either rotational direction
• Polyacrylate construction
• Metric dimensions for accurate fitment
• Inside diameter: 1.575 in. / 40.000 mm
• Outside diameter: 2.209 in. / 56.120 mm
• Width: 0.394 in. / 10.000 mm
• Housing bore: 2.206 in. / 56.000 mm
• Flanged outside diameter: 2.480 in. / 63.000 mm

Detailed Description

National 710540 is engineered as a metric transmission sealing component for the output shaft area. The seal measures 1.575 inches inside diameter, 2.209 inches outside diameter, and 0.394 inches in width, with an overall width of 0.669 inches including the side lip. Its polyacrylate material and bi-directional lip design support consistent sealing at the transmission output shaft where fluid retention is critical. This part is listed for 2000-2011 Ford Focus with Ford 4F27E Transmission and 2010-2013 Ford Transit Connect with Ford 4F27E Transmission. The part number 710540 is also referenced in interchange listings for related OE-style applications.

National has focused on sealing solutions for more than 75 years, and this seal reflects that experience in transmission and drivetrain sealing components. If you are servicing a Ford Focus or Ford Transit Connect with the 4F27E transmission, National 710540 provides the dimensional accuracy needed for a proper output shaft seal replacement.

This part cross-references Bosch 15128 for the same application.

What It Helps Address

• Transmission fluid seepage at the output shaft seal
• Fluid loss from a worn or hardened seal lip
• Contamination entering the transmission through a damaged seal area
• Leak-related drivability concerns tied to low transmission fluid level
• Service replacement for Ford 4F27E transmission seal wear

Installation Notes and Tips

• Verify shaft diameter, housing bore, and seal width before installation.
• Inspect the output shaft and seal bore for scoring, corrosion, or debris.
• Clean the sealing surfaces thoroughly before pressing the seal into place.
• Use care to avoid damaging the lip during installation.
• Confirm the application matches the vehicle and transmission code: Ford Focus and Ford Transit Connect with the 4F27E transmission.

Quality Assurance

National is a long-established sealing brand with a focus on precision-engineered replacement seals for automotive service. Part number 710540 is built to metric specifications and designed for transmission sealing applications where dimensional accuracy matters.