National 710539 Automatic Transmission Torque Converter Seal

Automatic Transmission Torque Converter Seal

National 710539 is an automatic transmission torque converter seal built for metric applications that require a precise housing and shaft fit. It uses a fluoro-elastomer sealing material and a clockwise-spiral lip design to help maintain a dependable seal in Ford and Mazda transmissions.

Fits 1999-2015 Ford Focus, Ford Fusion, Ford Transit Connect, Mazda 2, Mazda 3, Mazda 3 Sport, Mazda 5, Mazda 6, Mazda Protege, Mazda Protege5, and Mercury Milan applications listed with Ford 4F27E or FNR5 transmissions.

• National part number 710539 for automatic transmission torque converter sealing applications
• Fluoro-elastomer construction for transmission fluid sealing performance
• Clockwise-spiral lip design for consistent sealing contact
• Metric dimensions: 40.000 mm shaft inside diameter, 60.120 mm outside diameter, 5.500 mm width
• Housing bore size: 60.000 mm
• Part description: oil seal, Series 710500, Type 32

This seal is used in Ford 4F27E and Ford FNR5 transmission service where the torque converter seal must match the shaft and housing dimensions exactly. National 710539 is specified across multiple Mazda, Ford, and Mercury vehicles, including Mazda 3, Mazda 5, Mazda 6, Ford Focus, Ford Fusion, and Transit Connect applications. This part cross-references Bosch 15712 and 15718 for the same application.

Common Repair Uses

• Transmission fluid leakage at the torque converter seal area
• Seal wear from age, heat, or fluid contamination
• Service replacement during transmission rebuild or overhaul
• Loss of sealing integrity at the converter-to-pump interface
• Fitment-related sealing issues on 4F27E and FNR5-equipped vehicles

Installation Notes

Verify the transmission code before installation and match the seal to the housing bore, shaft diameter, and width listed for the application. Clean the sealing surface, inspect the converter hub and pump area for wear, and install the seal squarely to avoid lip damage. Confirm the seal orientation matches the clockwise-spiral lip design during assembly.

Quality Assurance

National has supplied sealing solutions for more than 75 years and continues to develop OE-style sealing components for modern vehicles. Part number 710539 reflects that focus on dimensional accuracy and transmission sealing performance for Ford and Mazda service work.