National 711120 Differential Pinion Seal - Rear Outer

Overview of National 711120 Differential Pinion Seal

The National 711120 differential pinion seal is engineered to provide reliable sealing performance for driveline systems. Designed for select Ford, Mercury, and Volvo models, this oil seal helps maintain optimal differential function by preventing fluid leaks and contamination.

• Flanged outside diameter: 0.315 inch (8.0 mm)
• Housing bore diameter: 1.969 inch (50.0 mm)
• Outside diameter: 1.976 inch (50.2 mm)
• Shaft diameter: 1.378 inch (35.0 mm)
• Width: 0.512 inch (13.0 mm)
• Material: durable polyacrylate
• Helix type: clockwise-spiral lip design for effective sealing
• Series: 711100

Technical Details and Design Features

This National differential pinion seal (part number 711120) features a polyacrylate construction that offers resistance to heat and wear, suitable for demanding driveline environments. The seal’s clockwise-spiral lip design enhances its ability to retain lubricants while preventing dirt and debris ingress. With precise dimensions including a 50 mm housing bore and a 35 mm shaft diameter, it ensures a secure fit in compatible differentials.

Its flanged outside diameter of 8 mm and overall width of 13 mm contribute to a stable installation, reducing the risk of seal displacement during operation. The 711120 seal is part of National’s 711100 series, known for consistent quality in gaskets and sealing systems.

Compatible Vehicles and Applications

This differential pinion seal is compatible with various Ford, Mercury, and Volvo models, including but not limited to:

• Ford Five Hundred, Freestyle, Montego
• Volvo S40, S60, S60 Cross Country, S80, S90, V50, V60, V60 Cross Country, V70, V90, V90 Cross Country, XC60, XC70, XC90
• Mercury models aligned with Ford platforms

Common Issues Addressed by the National 711120 Seal

• Prevents differential oil leaks that can cause driveline damage
• Protects against contamination from dirt and moisture
• Reduces wear on differential components by maintaining proper lubrication
• Helps avoid costly repairs related to seal failure
• Maintains differential efficiency and vehicle performance

Installation Notes and Tips

When installing the National 711120 differential pinion seal, ensure the housing bore and shaft are clean and free of debris. Use appropriate tools to press the seal evenly into place without distortion. Verify the seal’s orientation matches the clockwise-spiral lip design for optimal sealing. Lubricate the seal lip lightly with compatible differential oil before installation to reduce initial wear.

Quality Assurance and Warranty

National manufactures the 711120 differential pinion seal to meet industry standards for durability and performance. The polyacrylate material and precise engineering contribute to a reliable sealing solution. While specific warranty details may vary, National products typically come with a limited warranty against manufacturing defects, ensuring confidence in the part’s quality.