National 5208 Automatic Transmission Extension Housing Seal Kit - Rear

National 5208 Automatic Transmission Extension Housing Seal Kit Overview

The National 5208 Automatic Transmission Extension Housing Seal Kit is designed to provide reliable sealing performance for a variety of automatic transmissions. Engineered with nitrile sealing material, this oil seal kit ensures durability and resistance to transmission fluids, making it suitable for vehicles such as Chevrolet Silverado, Cadillac DeVille, and Jeep Cherokee.

• Includes Rp775 bushing for enhanced fitment
• Sealing material: durable nitrile rubber
• Inside diameter options: 1.887 inch (47.930 mm)
• Outside diameter: 1.999 inch (68.580 mm)
• Thickness/width: 1.000 inch (25.400 mm)

Technical Specifications and Material Details

This seal kit features a nitrile rubber construction, known for its excellent resistance to oil and heat, which is critical for maintaining transmission integrity. The kit includes a Rp775 bushing to ensure proper alignment and sealing within the extension housing. The seal’s inside diameter measures 1.887 inches (47.930 mm), while the outside diameter is 1.999 inches (68.580 mm), with a thickness of 1.000 inch (25.400 mm). These precise dimensions help maintain a secure seal around the transmission shaft, preventing fluid leaks and contamination.

Compatible Vehicles and Fitment Information

This National 5208 seal kit is compatible with a wide range of vehicles, including models from Aston Martin, Bentley, Buick, Cadillac, Chevrolet, GMC, Hummer, Jaguar, Jeep, Oldsmobile, Pontiac, and Rolls-Royce. Notable compatible models include Chevrolet Silverado 2500, Cadillac DeVille, Jeep Cherokee, and Buick LeSabre. Ensure compatibility by verifying the part number 5208 against your vehicle’s transmission specifications.

Common Applications and Problem Resolution

• Prevents automatic transmission fluid leaks from the extension housing
• Eliminates contamination ingress that can damage transmission components
• Reduces wear on transmission shafts by maintaining proper lubrication
• Addresses seal degradation due to heat and fluid exposure
• Helps maintain transmission pressure and performance

Installation Notes and Tips

When installing the National 5208 seal kit, ensure the transmission extension housing is clean and free of debris. Properly lubricate the seal with transmission fluid before installation to prevent damage. Use the included Rp775 bushing to align the seal correctly on the shaft. Avoid using excessive force during installation to maintain the integrity of the nitrile material. Verify the seal is seated evenly to prevent leaks.

Quality Assurance and Warranty

National transmission seal kits are manufactured to meet OEM standards for fit and function. The nitrile material used in the 5208 kit offers reliable resistance to heat and transmission fluids, contributing to long service life. While specific warranty details may vary, National products typically come with a limited warranty against defects in material and workmanship. Consult product documentation for exact warranty terms.