National 5200 Automatic Transmission Extension Housing Seal Kit - Rear

Overview of National 5200 Automatic Transmission Extension Housing Seal Kit

The National 5200 Automatic Transmission Extension Housing Seal Kit is designed for reliable sealing performance in a variety of GM and other domestic vehicles. This oil seal kit includes both a 9613s seal and an rp356 bushing, engineered to maintain transmission integrity and prevent fluid leaks.

• Includes 9613s seal and rp356 bushing for comprehensive sealing
• Constructed from durable nitrile sealing material
• Counter-clockwise spiral lip design for enhanced sealing efficiency
• Fits a wide range of Buick, Chevrolet, GMC, and other models
• Precision dimensions ensure proper fit and function

Technical Specifications and Features

This National 5200 kit features a nitrile sealing material known for its resistance to oil and heat, suitable for automatic transmission extension housings. The seal has an inside diameter of 1.502 inches (38.150 mm) and an outside diameter of 2.381 inches (60.480 mm), with a thickness of 0.470 inches (11.940 mm). The flanged outside diameter measures 2.550 inches (64.770 mm), designed to fit housing bores of 2.377 inches (60.380 mm). The kit’s counter-clockwise spiral lip design helps maintain a tight seal under varying operating conditions, reducing the risk of leaks and contamination.

Compatible Vehicles and Fitment Details

This extension housing seal kit is compatible with numerous makes and models, including Buick, Cadillac, Chevrolet, Geo, GMC, Isuzu, Jeep, Oldsmobile, Pontiac, and Suzuki. It fits popular models such as the Chevrolet Blazer, Camaro, C1500, Corvette, and Silverado series, as well as Buick LeSabre, Cadillac DeVille, and Pontiac Grand Prix. The National 5200 part number is specifically designed to meet the requirements of these vehicles’ automatic transmission systems, ensuring proper fit and function.

Common Applications and Problem Resolution

• Prevents automatic transmission fluid leaks from the extension housing
• Replaces worn or damaged seals and bushings to restore transmission performance
• Helps reduce contamination and wear inside the transmission assembly
• Addresses issues related to fluid seepage causing transmission slippage or overheating
• Supports maintenance and rebuilds of automatic transmission extension housings

Installation Notes and Tips

When installing the National 5200 seal kit, ensure the transmission extension housing bore is clean and free of debris. Lubricate the nitrile seal lightly with transmission fluid before installation to prevent damage to the sealing lip. Use proper tools to press the seal and bushing evenly into place without distortion. Verify the counter-clockwise spiral lip orientation matches the original seal to maintain sealing effectiveness. Follow vehicle-specific service manual instructions for torque specifications and assembly procedures.

Quality Assurance and Warranty Information

National manufactures this extension housing seal kit to meet OEM standards for durability and performance. The nitrile material and precision engineering provide reliable sealing under normal operating conditions. While specific warranty details may vary, National products typically come with a limited warranty against defects in materials and workmanship. Always consult product documentation or the manufacturer for exact warranty terms.