National 253747 Automatic Transmission Oil Pump Seal - Front

Overview of National 253747 Automatic Transmission Oil Pump Seal

The National 253747 automatic transmission oil pump seal is engineered to provide reliable sealing performance for select Chevrolet, Oldsmobile, and Pontiac models. Designed with durable nitrile material, this oil seal ensures effective containment of transmission fluid, helping maintain optimal transmission function.

• Inside diameter: 0.625 inch (15.880 mm)
• Outside diameter: 0.880 inch (22.350 mm)
• Thickness/width: 0.125 inch (3.180 mm)
• Sealing material: Nitrile for resistance to heat and transmission fluids
• Compatible housing bore: 0.875 inch (22.230 mm)

Technical Details and Specifications

This National automatic transmission oil pump seal (part number 253747) is constructed from nitrile, a synthetic rubber known for its resistance to oil, heat, and wear. The seal features a 0.625 inch (15.880 mm) inside diameter and a 0.880 inch (22.350 mm) outside diameter, with a thickness of 0.125 inch (3.180 mm). It is designed to fit a housing bore of 0.875 inch (22.230 mm), making it suitable for precise sealing applications in automatic transmission oil pumps.

Compatible Vehicle Applications

This oil pump seal is compatible with various Chevrolet, Oldsmobile, and Pontiac vehicles, including models such as the Chevrolet Cavalier, Oldsmobile Cutlass Ciera, Pontiac Fiero, Firenza, Celebrity, J2000, and J2000 Sunbird. Using the National 253747 seal helps maintain proper transmission fluid containment and prevents leaks in these specific vehicle models.

Common Issues Addressed by This Oil Pump Seal

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

Installation Notes and Tips

• Ensure the housing bore and shaft dimensions match the seal specifications before installation
• Clean the sealing surfaces thoroughly to remove debris and old sealant
• Lubricate the seal lip with transmission fluid prior to installation to prevent damage
• Press the seal evenly into the housing bore to avoid distortion
• Verify proper seating and alignment to ensure effective sealing

Quality Assurance and Warranty

National transmission seals are manufactured to meet industry standards for durability and performance. The 253747 oil pump seal is made from high-quality nitrile material to withstand exposure to transmission fluids and operating temperatures. While specific warranty details may vary, National products typically come with a limited warranty against manufacturing defects to provide confidence in product reliability.