National 240735 Manual Transmission Shift Shaft Seal

Overview of National 240735 Manual Transmission Shift Shaft Seal

The National 240735 manual transmission shift shaft seal is engineered to provide reliable sealing performance for a variety of GM vehicles. Designed with durable nitrile material, this oil seal helps maintain transmission integrity by preventing fluid leaks and contamination.

• Inside diameter: 0.750 inch (19.05 mm)
• Outside diameter: 1.010 inch (25.65 mm)
• Thickness: 0.156 inch (3.96 mm)
• Sealing material: Nitrile for resistance to oil and wear
• Compatible with multiple Buick, Chevrolet, GMC, Oldsmobile, and Pontiac models

Technical Specifications and Material Details

This manual transmission shift shaft seal from National is part of the 240000 series, featuring a 0.750 inch (19.05 mm) shaft size and a housing bore of approximately 0.999 inch (25.37 mm). The seal’s nitrile construction offers effective resistance to oil, heat, and mechanical wear, ensuring a tight seal around the shift shaft. With an outside diameter of 1.010 inch (25.65 mm) and a thickness of 0.156 inch (3.96 mm), it fits precisely within the transmission housing to prevent leaks.

Compatible Vehicles and Applications

This National 240735 shift shaft seal is compatible with a wide range of manual transmission applications in GM vehicles, including Buick, Chevrolet, GMC, Oldsmobile, and Pontiac models. Notable compatible models include the Chevrolet Camaro, Corvette, Blazer, C10 series trucks, and Pontiac Firebird, among others. It is designed to replace worn or damaged seals in these vehicles to maintain proper transmission function.

Common Issues Addressed by the Shift Shaft Seal

• Prevents manual transmission fluid leaks around the shift shaft
• Reduces contamination ingress that can cause premature wear
• Maintains proper lubrication within the transmission assembly
• Helps avoid shifting difficulties caused by fluid loss
• Protects transmission components from dirt and debris

Installation Notes and Tips

When installing the National 240735 shift shaft seal, ensure the transmission housing bore is clean and free of debris. Carefully align the seal with the shaft and press it evenly into place to avoid distortion. Lubricate the sealing lip with transmission fluid before installation to reduce initial wear. Verify the seal seating to prevent leaks and ensure smooth shifting operation.

Quality Assurance and Warranty Information

National manufactures this shift shaft seal to meet industry standards for durability and performance. The nitrile material is selected for its resistance to oil and mechanical stress, contributing to long service life. While specific warranty details may vary, National products typically come with a limited warranty against manufacturing defects, providing confidence in the part’s reliability.