National 340849 Automatic Transmission Oil Pump Seal - Front

Overview of National 340849 Automatic Transmission Oil Pump Seal

The National 340849 automatic transmission oil pump seal is engineered to provide reliable sealing performance for select GM vehicles. Designed with precision nitrile material, this oil seal ensures durability and effective fluid retention in transmission systems of Buick, Cadillac, Chevrolet, Oldsmobile, and Pontiac models.

• Inside diameter: 0.625 inch (15.880 mm)
• Outside diameter: 0.883 inch (22.430 mm)
• Thickness: 0.093 inch (2.360 mm)
• Sealing material: Nitrile for resistance to transmission fluids
• Compatible with housing bore size: 0.875 inch (22.230 mm)

Detailed Product Description and Specifications

This National 340849 oil seal is part of the 340000 series, designed specifically for automatic transmission oil pumps. The seal’s nitrile construction offers excellent resistance to heat, oil, and wear, making it suitable for continuous operation within transmission assemblies. With an inside diameter of 0.625 inch and an outside diameter of 0.883 inch, it fits precisely on shafts and housing bores specified for Buick Century, Cadillac Cimarron, Chevrolet Citation, Oldsmobile Firenza, Pontiac Omega, Phoenix, Skyhawk, and Skylark models. The 0.093 inch thickness ensures a secure seal without compromising the pump’s mechanical function.

Compatible Vehicle Applications

This oil pump seal is compatible with the following makes and models:

• Buick Century
• Cadillac Cimarron
• Chevrolet Citation
• Oldsmobile Firenza
• Pontiac Omega, Phoenix, Skyhawk, Skylark

Ensure compatibility by verifying the transmission model and shaft dimensions before installation.

Common Issues Addressed by the National 340849 Seal

• Prevents automatic transmission fluid leaks around the oil pump shaft
• Reduces contamination ingress into the transmission system
• Maintains proper hydraulic pressure within the transmission
• Minimizes premature wear of transmission components due to fluid loss
• Helps avoid transmission overheating caused by fluid leakage

Installation Notes and Tips

• Inspect the housing bore and shaft for wear or damage before installation
• Clean all mating surfaces thoroughly to ensure proper sealing
• Use appropriate tools to press the seal evenly into the housing bore
• Lubricate the seal lip with transmission fluid prior to installation to prevent damage
• Verify correct orientation of the seal to maintain fluid retention

Quality Assurance and Warranty Information

Manufactured by National, a recognized brand in transmission sealing systems, the 340849 oil pump seal meets industry standards for material quality and dimensional accuracy. The nitrile material is selected for its compatibility with automatic transmission fluids and resistance to wear. While specific warranty details may vary, National typically offers coverage against manufacturing defects to ensure product reliability.