National 5723 Engine Crankshaft Seal - Rear

Overview of National Engine Crankshaft Seal 5723

The National 5723 engine crankshaft seal is designed for reliable sealing performance in Ford trucks and vans. Engineered with precision, this oil seal kit ensures effective protection against oil leaks in various Ford E-350 and F-Series models.

• Inside diameter: 4.375 inches (111.130 mm)
• Outside diameter: 5.179 inches (131.550 mm)
• Thickness: 0.400 inches (10.160 mm)
• Material: Durable PTFE for enhanced wear resistance
• Helix type: Counter-clockwise spiral lip design for optimal sealing
• Compatible housing bore: 5.169 inches (131.290 mm)
• Part type: Forward-facing hub (Fw-h) oil seal

Detailed Product Description

The National 5723 crankshaft seal is part of the 5700 series, crafted to meet the demanding requirements of Ford vehicles such as the E-350 Club Wagon, E-350 Econoline, F-250 Super Duty, and F-350 Super Duty. Constructed from PTFE material, this seal offers excellent chemical resistance and durability under high-temperature engine conditions. The counter-clockwise spiral lip design enhances sealing efficiency by maintaining consistent contact with the crankshaft, reducing oil leakage and contamination risks. With precise dimensions including a 4.375-inch shaft diameter and a 5.179-inch outside diameter, this seal fits securely within the housing bore of 5.169 inches, ensuring a tight and reliable fit.

Compatible Ford Models and Applications

This engine crankshaft seal is compatible with the following Ford models:

• Ford E-350 Club Wagon
• Ford E-350 Econoline and Econoline Club Wagon
• Ford E-350 Super Duty
• Ford Excursion
• Ford F-250, F-250 HD, and F-250 Super Duty
• Ford F-350 and F-350 Super Duty

Common Issues Addressed by National 5723 Seal

• Prevents oil leaks around the crankshaft area
• Reduces engine contamination from external debris
• Maintains engine oil pressure and performance
• Minimizes wear on crankshaft and seal interface
• Helps avoid costly engine repairs due to oil loss

Installation Notes and Tips

• Ensure the crankshaft and housing bore are clean and free of debris before installation
• Use proper tools to avoid damaging the PTFE seal lip during installation
• Verify the seal orientation matches the counter-clockwise spiral lip design
• Check for correct fitment with the 4.375-inch shaft and 5.179-inch housing bore dimensions
• Apply a light coat of engine oil on the seal lip to facilitate smooth installation

Quality Assurance and Warranty

National's 5723 engine crankshaft seal is manufactured to meet industry standards for durability and performance. The use of PTFE material and precise engineering ensures long service life under typical operating conditions. While specific warranty details may vary, National products generally come with a limited warranty against manufacturing defects, providing confidence in product reliability.