National 714654 Manual Transmission Output Shaft Seal

Overview of National Manual Transmission Output Shaft Seal 714654

The National 714654 manual transmission output shaft seal is engineered to provide reliable sealing performance for select Chevrolet and GMC trucks and SUVs. Designed with durable polyacrylate material and a counter-clockwise spiral lip, this oil seal helps maintain transmission integrity by preventing fluid leaks.

• Constructed from high-quality polyacrylate for durability and resistance
• Counter-clockwise spiral lip design for effective sealing
• Inside diameter of 2.000 inches (50.8 mm) to fit output shafts precisely
• Outside diameter of 3.003 inches (76.28 mm) matching housing bore dimensions
• Thickness of 0.438 inches (11.13 mm) for proper fit and sealing depth
• Redicoat surface treatment to enhance wear resistance
• Compatible with multiple Chevrolet and GMC models including Silverado, Sierra, Tahoe, Yukon, and more

Detailed Product Description

The National 714654 output shaft seal is part of the 714000 series, designed specifically for manual transmissions requiring a 47-type seal. Its polyacrylate construction offers chemical and temperature resistance suitable for transmission environments. The seal features a counter-clockwise spiral lip that ensures a tight seal around the 2.000-inch (50.8 mm) diameter shaft, preventing oil leakage and contamination. The outside diameter of 3.003 inches (76.28 mm) corresponds closely with the housing bore size of approximately 2.996 inches (76.1 mm), ensuring a secure fit. The 0.438-inch (11.13 mm) thickness provides the necessary width for effective sealing without compromising installation space. Additionally, the Redicoat treatment enhances the seal’s surface durability, extending service life under demanding conditions.

Compatible Vehicles and Applications

This manual transmission output shaft seal is compatible with a range of Chevrolet and GMC vehicles, including:

• Chevrolet Blazer, C1500, C2500, C3500, Silverado 1500, 2500, 3500, Tahoe
• GMC Sierra 1500, 2500, 2500 HD, 3500, Yukon, P30, P3500

It is designed to replace worn or damaged output shaft seals in manual transmissions, helping to maintain proper fluid retention and transmission performance.

Common Issues Addressed by Part Number 714654

• Prevents manual transmission fluid leaks from the output shaft area
• Reduces contamination ingress that can cause premature transmission wear
• Eliminates noise and vibration caused by worn or damaged seals
• Maintains proper lubrication levels within the transmission
• Helps avoid costly transmission repairs due to fluid loss

Installation Notes and Tips

When installing the National 714654 output shaft seal, ensure the transmission output shaft and housing bore are clean and free of debris. Use appropriate tools to press the seal evenly into the housing bore without damaging the sealing lip. Verify the seal orientation matches the counter-clockwise spiral lip design for optimal sealing performance. It is recommended to inspect the shaft surface for wear or damage before installation to ensure a proper seal.

Quality Assurance and Warranty

National transmission seals are manufactured to meet industry standards for fit and function. The 714654 seal undergoes quality control inspections to ensure dimensional accuracy and material integrity. While specific warranty details are not provided, National products typically adhere to OEM quality requirements, offering reliable service when installed correctly.