National 4583 Manual Transmission Output Shaft Seal

Overview of National 4583 Manual Transmission Output Shaft Seal

The National 4583 manual transmission output shaft seal is engineered to provide reliable sealing performance for a range of GM and related vehicles. Designed with precision dimensions and durable polyacrylate material, this oil seal helps maintain transmission integrity and prevent fluid leaks.

• Inside diameter: 1.502 inches (38.150 mm)
• Outside diameter: 2.381 inches (60.480 mm)
• Flanged outside diameter: 2.717 inches (69.000 mm)
• Thickness: 0.374 inches (9.500 mm)
• Sealing material: Polyacrylate with counter-clockwise spiral lip design
• Redicoat finish for enhanced durability
• Compatible with multiple GM makes and models

Technical Details and Material Specifications

This National 4583 output shaft seal features a polyacrylate sealing material known for its resistance to heat and transmission fluids. The counter-clockwise spiral lip design improves sealing efficiency by directing fluid away from the shaft, reducing the risk of leaks. The seal’s flanged outside diameter of 2.717 inches ensures a secure fit within the housing bore, which measures 2.377 inches (60.380 mm). The 0.374-inch thickness provides a robust barrier against contaminants and fluid loss.

Compatible Vehicles and Applications

This manual transmission output shaft seal is compatible with a wide range of vehicles including Buick, Cadillac, Chevrolet, GMC, Hummer, Isuzu, Oldsmobile, Pontiac, and Saab models. Notable compatible models include the Chevrolet Silverado 1500, GMC Sierra 1500, Cadillac Escalade, Hummer H2, and Saab 9-7x. The part number 4583 is specifically designed to meet the sealing requirements of these vehicles’ manual transmissions.

Common Issues Addressed by National 4583 Seal

• Prevents manual transmission fluid leaks from the output shaft
• Reduces contamination ingress into the transmission housing
• Minimizes wear on transmission components caused by fluid loss
• Maintains proper lubrication for output shaft bearings
• Helps avoid costly transmission repairs due to seal failure

Installation Notes and Tips

Ensure the housing bore and shaft surfaces are clean and free of debris before installation. Use appropriate tools to press the seal evenly into the bore without distortion. Verify the seal’s orientation matches the counter-clockwise spiral lip design to optimize sealing performance. Lubricate the seal lip lightly with transmission fluid prior to installation to reduce initial wear.

Quality Assurance and Warranty

National 4583 output shaft seals are manufactured to meet industry standards for durability and fitment. The Redicoat finish enhances corrosion resistance, extending the service life of the seal. While specific warranty terms may vary, National products typically come with a limited warranty against manufacturing defects, ensuring reliability for professional and DIY transmission repairs.