National 240816 Manual Transmission Shift Shaft Seal

Overview of National Manual Transmission Shift Shaft Seal 240816

The National 240816 manual transmission shift shaft seal is engineered to provide reliable sealing performance for select Ford and Mercury vehicles. Designed with durable nitrile material, this oil seal helps maintain transmission integrity by preventing fluid leaks around the shift shaft.

• Inside diameter: 0.750 inch (19.05 mm)
• Outside diameter: 1.072 inch (27.23 mm)
• Thickness/width: 0.187 inch (4.75 mm)
• Sealing material: Nitrile for resistance to oil and wear
• Compatible housing bore: 1.062 inch (26.97 mm)

Detailed Product Description

The National 240816 shift shaft seal is part of the 240000 series, designed specifically for manual transmissions in various Ford and Mercury models including the Bronco, Mustang, Econoline series, and others. Constructed from nitrile, this seal offers effective resistance to oil and transmission fluids, ensuring a tight seal around the 0.750 inch (19.05 mm) diameter shift shaft. Its precise dimensions—1.072 inch (27.23 mm) outside diameter and 0.187 inch (4.75 mm) thickness—allow for a secure fit within a 1.062 inch (26.97 mm) housing bore, minimizing the risk of leaks and contamination.

Applications and Common Issues Addressed

• Prevents manual transmission fluid leaks around the shift shaft
• Reduces contamination ingress into the transmission system
• Helps maintain proper transmission function and shift quality
• Addresses wear-related seal degradation in Ford Bronco and Mustang models
• Suitable for use in Mercury Cougar and Grand Marquis manual transmissions

Installation Notes and Tips

Ensure the housing bore and shaft are clean and free of debris before installation. Carefully press the seal into the housing bore without damaging the sealing lip. Verify the seal is seated evenly to prevent leaks. Use appropriate tools to avoid distortion of the nitrile material during installation.

Quality Assurance and Warranty

National transmission seals are manufactured to meet OEM specifications for fit and function. The nitrile material provides durability against oil exposure and mechanical wear. While specific warranty details are not provided, National products are generally backed by quality standards consistent with automotive industry requirements.