National 100085 Engine Crankshaft Seal - Rear

Overview of National Engine Crankshaft Seal 100085

The National Engine Crankshaft Seal part number 100085 is designed to provide reliable sealing performance for a range of GM and related vehicles. Engineered with a counter-clockwise spiral lip design and made from durable PTFE material, this oil seal helps maintain engine integrity by preventing oil leaks around the crankshaft.

• Inside diameter: 3.858 inches (97.99 mm)
• Outside diameter: 4.540 inches (115.32 mm)
• Thickness: 0.492 inches (12.5 mm)
• Counter-clockwise spiral lip design for effective sealing
• Constructed from PTFE for enhanced durability and chemical resistance
• Compatible with housing bore size of 4.525 inches (114.94 mm)

Technical Details and Specifications

This National crankshaft seal features a precise fit with an inside diameter of 3.858 inches and an outside diameter of 4.540 inches, making it suitable for crankshafts requiring these dimensions. The thickness of 0.492 inches ensures a secure seal without excessive friction. The counter-clockwise spiral lip design improves sealing efficiency by directing oil back into the engine, reducing leakage. Manufactured from PTFE, the seal offers resistance to heat, oil, and wear, which is critical for maintaining engine performance over time.

Compatible Vehicles and Applications

This engine crankshaft seal is compatible with a wide range of vehicles including Buick, Cadillac, Chevrolet, GMC, Hummer, Isuzu, Pontiac, and Saab models. Specific fitment includes popular models such as the Chevrolet Silverado 1500, GMC Sierra 2500 HD, Cadillac Escalade, Buick LaCrosse, and Hummer H2. The part number 100085 is designed to meet the sealing requirements of these vehicles’ crankshafts, ensuring proper engine operation and oil containment.

• Prevents oil leaks around the crankshaft
• Reduces engine contamination from external debris
• Maintains oil pressure and engine lubrication
• Minimizes wear on crankshaft and housing bore
• Helps avoid costly engine repairs due to seal failure

Installation Notes and Tips

When installing the National crankshaft seal 100085, ensure the housing bore is clean and free of debris. Use proper tools to avoid damaging the PTFE lip during installation. Align the seal carefully with the crankshaft to maintain the counter-clockwise spiral lip orientation. Lubricate the seal lip lightly with engine oil before installation to reduce initial wear. Verify the seal is seated evenly to prevent leaks and premature failure.

Quality Assurance and Warranty

National engine seals are manufactured to meet industry standards for durability and performance. The PTFE material and precision design contribute to long service life under normal operating conditions. While specific warranty details for part number 100085 may vary, National typically offers coverage against manufacturing defects. Always consult product documentation or authorized sources for warranty terms.