National 7929S Automatic Transmission Manual Shaft Seal

Overview of National 7929S Automatic Transmission Manual Shaft Seal

The National 7929S is a precision-engineered automatic transmission manual shaft seal designed for reliable sealing performance. Constructed from durable nitrile material, this oil seal is compatible with a range of Ford, Jaguar, Lincoln, Mazda, and Mercury vehicles, including popular models like the Ford Explorer, Lincoln Town Car, and Mazda B2300.

• Inside diameter: 0.742 inch (18.85 mm)
• Outside diameter: 1.067 inch (27.1 mm)
• Thickness/width: 0.187 inch (4.75 mm)
• Sealing material: Nitrile for resistance to oil and heat
• Housing bore size: 1.063 inch (27.0 mm)
• Part type: Automatic transmission manual shaft oil seal
• Series: 7000

Detailed Product Description and Specifications

The National 7929S automatic transmission manual shaft seal is manufactured using nitrile, a synthetic rubber known for its excellent resistance to petroleum-based fluids and high temperatures. This seal features an inside diameter of 0.742 inches (18.85 mm) and an outside diameter of 1.067 inches (27.1 mm), with a thickness of 0.187 inches (4.75 mm), making it suitable for precise fitment in the transmission housing bore of 1.063 inches (27.0 mm). The seal’s design ensures effective containment of transmission fluid, preventing leaks and contamination that could lead to transmission damage.

Compatible Vehicles and Applications

This National 7929S seal is compatible with a wide range of vehicles, including Ford models such as the Explorer, F-150, Mustang, and Crown Victoria; Lincoln models like the Town Car and Navigator; Jaguar XJ series; Mazda B2300 and B4000; and Mercury Mountaineer and Marquis. It is specifically designed for use in automatic transmissions requiring a manual shaft seal, ensuring proper sealing and longevity of the transmission system.

Common Issues Addressed by the National 7929S Seal

• Prevents transmission fluid leaks around the manual shaft
• Reduces contamination ingress into the transmission system
• Minimizes wear caused by fluid loss and dirt exposure
• Maintains proper hydraulic pressure within the transmission
• Helps avoid costly transmission repairs due to seal failure

Installation Notes and Tips

• Ensure the transmission housing bore is clean and free of debris before installation
• Use appropriate tools to avoid damaging the nitrile seal during installation
• Verify the seal orientation matches the original part for correct sealing
• Check shaft and bore dimensions to confirm compatibility with the 0.742 inch shaft diameter and 1.063 inch housing bore
• Lubricate the seal lip lightly with transmission fluid before installation to reduce initial wear

Quality Assurance and Warranty Information

National’s 7929S seal is manufactured to meet industry standards for durability and performance. Made from high-quality nitrile material, it offers reliable sealing under typical operating conditions. While specific warranty details may vary, National products generally come with a limited warranty against manufacturing defects, ensuring confidence in the product’s quality and longevity.