National 4189H Automatic Transmission Torque Converter Seal

Overview of National 4189H Automatic Transmission Torque Converter Seal

The National 4189H automatic transmission torque converter seal is engineered for reliable sealing performance in select Ford, Lincoln, and Mercury vehicles. Designed to maintain fluid integrity, this oil seal supports smooth transmission operation in models such as the Ford Taurus, Lincoln Continental, and Mercury Sable.

• Inside diameter options: 1.996 inch (50.700 mm)
• Outside diameter: 3.120 inch (79.250 mm)
• Flanged outside diameter: 3.425 inch (87.000 mm)
• Thickness: 0.344 inch (8.740 mm)
• Material: durable fluoro-elastomer for heat and chemical resistance
• Redicoat surface treatment for enhanced sealing and wear protection
• Compatible with housing bore diameter of 3.111 inch (79.020 mm)

Detailed Product Description

The National 4189H torque converter seal is part of the Series 4000 line, known for its precision-engineered sealing components. Constructed from fluoro-elastomer, this seal offers resistance to high temperatures and transmission fluids, ensuring long-lasting performance. The seal’s flanged outside diameter of 3.425 inches (87 mm) and inside diameter of 1.996 inches (50.7 mm) provide a secure fit around the torque converter shaft and housing bore. The 0.344 inch (8.74 mm) thickness balances durability with flexibility to maintain a tight seal under varying operating conditions. The Redicoat coating enhances the seal’s surface, reducing wear and improving fluid retention.

Compatible Vehicles and Applications

This automatic transmission torque converter seal is compatible with several Ford, Lincoln, and Mercury models, including:

• Ford Taurus
• Lincoln Continental
• Mercury Sable
• Ford Freestar
• Mercury Windstar

It is designed specifically for use in automatic transmissions requiring a 75-type seal with the specified dimensions, ensuring proper fit and function.

Common Issues Addressed by the National 4189H Seal

• Prevents transmission fluid leaks around the torque converter shaft
• Reduces risk of contamination entering the transmission system
• Maintains hydraulic pressure for smooth transmission shifting
• Minimizes wear on transmission components caused by fluid loss
• Helps avoid costly transmission repairs due to seal failure

Installation Notes and Tips

• Ensure the housing bore and shaft are clean and free of debris before installation
• Use appropriate tools to avoid damaging the fluoro-elastomer material during installation
• Verify the seal orientation matches the original part to maintain proper sealing
• Check for correct fitment with the 3.111 inch (79.020 mm) housing bore and 1.996 inch (50.700 mm) shaft diameter
• Apply a light coating of transmission fluid to the seal lip before installation to ease assembly

Quality Assurance and Warranty

National’s 4189H torque converter seal is manufactured to meet industry standards for durability and performance. The use of fluoro-elastomer material and Redicoat treatment ensures resistance to heat, chemicals, and wear. While specific warranty details may vary, National typically offers coverage against manufacturing defects to provide confidence in product reliability.