National 5203 Automatic Transmission Extension Housing Seal Kit

Overview of National 5203 Automatic Transmission Extension Housing Seal Kit

The National 5203 Automatic Transmission Extension Housing Seal Kit is designed for reliable sealing performance in select Ford, Lincoln, and Mercury vehicles. This kit includes a high-quality 7300s seal and rp661 bushing, engineered to maintain transmission integrity and prevent fluid leaks.

• Includes 7300s seal and rp661 bushing for comprehensive sealing
• Constructed from durable nitrile material for resistance to heat and wear
• Counter-clockwise spiral lip design (helix type) enhances sealing efficiency
• Flanged outside diameter measures 2.850 inches (72.390 mm)
• Fits housing bore diameter of 2.500 inches (63.500 mm)
• Overall width with side lip is 1.250 inches (31.750 mm)
• Redicoat finish for added corrosion protection

Detailed Product Description and Specifications

The National 5203 seal kit is part of the 5200 series and is specifically designed for automatic transmission extension housings. The kit’s 7300s oil seal and rp661 bushing are made from nitrile, a material known for its excellent resistance to oil, heat, and abrasion. The seal features a counter-clockwise spiral lip design that improves sealing performance by directing fluid away from the shaft, reducing leakage risks. The flanged outside diameter of 2.850 inches and housing bore of 2.500 inches ensure a precise fit for compatible transmissions. The overall width of 1.250 inches with side lip provides a secure seal, while the redicoat finish offers additional protection against corrosion and wear.

Compatible Vehicles and Applications

This transmission extension housing seal kit is compatible with a range of Ford, Lincoln, and Mercury models, including but not limited to:

• Ford Bronco, F-150, F-250, F-350, E-150 Econoline, Excursion, Mustang
• Lincoln Continental, Navigator, Town Car, Mark series
• Mercury Cougar, Grand Marquis, Villager, Capri

Use the National 5203 kit when servicing automatic transmissions on these vehicles to ensure proper sealing and transmission performance.

Common Issues Addressed by the National 5203 Seal Kit

• Prevents automatic transmission fluid leaks from the extension housing
• Reduces contamination and debris ingress into the transmission
• Minimizes wear on transmission shafts and bushings
• Helps maintain proper transmission pressure and fluid levels
• Addresses seal and bushing wear due to age or damage

Installation Notes and Tips

• Ensure the transmission extension housing bore is clean and free of debris before installation
• Lubricate the seal and bushing with transmission fluid to ease installation and prevent damage
• Use proper tools to press the seal and bushing evenly into place without distortion
• Verify correct orientation of the counter-clockwise spiral lip seal for optimal sealing
• Inspect the shaft for wear or damage and replace if necessary before installing the new seal kit

Quality Assurance and Warranty Information

National parts are manufactured to meet or exceed OEM specifications, ensuring reliable performance and durability. The 5203 Automatic Transmission Extension Housing Seal Kit undergoes rigorous quality control to maintain consistent standards. While specific warranty terms may vary, National typically offers coverage against manufacturing defects. Consult product documentation or the manufacturer for detailed warranty information.