National 4503N Transfer Case Output Shaft Seal - Rear

National 4503N Transfer Case Output Shaft Seal Overview

The National 4503N transfer case output shaft seal is engineered to provide reliable sealing performance for a range of GM and Ford trucks and SUVs. Designed with durable polyacrylate material and a bi-directional lip design, this oil seal helps maintain proper lubrication and prevent leaks in demanding transfer case applications.

• Inside diameter options: 1.886 inch (47.9 mm)
• Outside diameter: 2.765 inch (70.23 mm)
• Flanged outside diameter: 3.270 inch (83.06 mm)
• Thickness: 0.469 inch (11.9 mm)
• Bi-directional lip design for effective sealing
• Constructed from durable polyacrylate sealing material
• Fits housing bore diameter of 2.750 inch (69.85 mm)
• Overall width with side lip: 1.375 inch (34.93 mm)

Detailed Product Description

The National 4503N transfer case output shaft seal is part of the 4000 series and is specifically designed to fit transfer cases on various GM and Ford vehicles, including Chevrolet Silverado 1500, GMC Sierra 1500, Cadillac Escalade, Ford F-150, and Ram 1500 models. The seal features a bi-directional lip design that provides effective sealing against oil leaks in both rotational directions, which is critical for transfer case output shafts that experience torque in multiple directions.

Manufactured from polyacrylate, the seal offers resistance to heat, oil, and wear, ensuring long service life under harsh operating conditions. The precise dimensions, including a 1.886 inch inside diameter and a 2.765 inch outside diameter, ensure a secure fit within the housing bore of 2.750 inches. The flanged outside diameter of 3.270 inches provides additional stability during installation and operation.

Compatible Vehicles and Applications

This transfer case output shaft seal is compatible with a wide range of trucks and SUVs, including:

• Chevrolet Silverado 1500, Avalanche, Colorado, Suburban 1500, Tahoe
• GMC Sierra 1500, Canyon, Yukon, Yukon XL 1500
• Cadillac Escalade, Escalade ESV, Escalade EXT
• Ford F-150, F-250, F-350, Expedition
• Ram 1500, 1500 Classic, and other models
• Hummer H2, H3, H3T
• Lincoln Navigator, Mark LT
• Oldsmobile Bravada, Safari
• Chevrolet Astro, Express 1500, Express 2500, Savana 1500, Savana 2500

Common Issues Addressed by the National 4503N Seal

• Prevents transfer case fluid leaks from the output shaft area
• Reduces contamination ingress to protect internal transfer case components
• Maintains proper lubrication to extend transfer case life
• Eliminates noise and vibration caused by worn or damaged seals
• Helps avoid costly transfer case repairs due to fluid loss

Installation Notes and Tips

When installing the National 4503N transfer case output shaft seal, ensure the housing bore is clean and free of debris. Use appropriate tools to press the seal evenly into place without damaging the sealing lip. Verify the seal orientation matches the bi-directional lip design for optimal performance. It is recommended to inspect the output shaft for wear or damage before installation to ensure a proper seal.

Quality Assurance and Warranty

National transfer case output shaft seals are manufactured to meet OEM specifications for fit, form, and function. The polyacrylate material and bi-directional lip design provide reliable sealing performance under typical operating conditions. While specific warranty details are not provided, National products are known for consistent quality and durability in automotive sealing applications.