National 100727 Differential Pinion Seal - Rear Outer

National Differential Pinion Seal 100727 Overview

The National Differential Pinion Seal 100727 is engineered for reliable sealing performance in heavy-duty driveline applications. Designed specifically for Chevrolet, Dodge, and GMC trucks, this oil seal ensures proper containment of lubricants in the differential pinion area, helping maintain optimal drivetrain function.

• Inside diameter: 2.500 inches (63.5 mm)
• Outside diameter: 4.042 inches (102.67 mm)
• Flanged outside diameter: 4.331 inches (110 mm)
• Thickness: 0.492 inches (12.5 mm)
• Material: Durable fluoro-elastomer for enhanced resistance to heat and chemicals
• Compatible with Chevrolet Silverado 3500, GMC Sierra 3500 and Sierra 3500 Classic, Dodge Ram 2500 and Ram 3500

Technical Details and Specifications

This National differential pinion seal features a precise inside diameter of 2.500 inches (63.5 mm) to fit the pinion shaft securely, while the outside diameter measures 4.042 inches (102.67 mm) to match the housing bore. The flanged outside diameter of 4.331 inches (110 mm) provides additional sealing surface and stability within the differential housing. With a thickness of 0.492 inches (12.5 mm), the seal offers a robust barrier against oil leaks. Constructed from fluoro-elastomer, the seal resists degradation from heat, oil, and other automotive fluids, ensuring long service life under demanding conditions.

Compatible Vehicles and Applications

This differential pinion seal is compatible with select heavy-duty trucks, including Chevrolet Silverado 3500, GMC Sierra 3500 and Sierra 3500 Classic, as well as Dodge Ram 2500 and Ram 3500 models. It is designed to maintain proper sealing in the differential pinion area, preventing lubricant leaks and protecting drivetrain components from contamination.

• Prevents oil leaks in differential pinion area
• Protects against dirt and debris intrusion
• Maintains proper lubrication for differential gears
• Reduces risk of drivetrain damage due to seal failure
• Helps maintain vehicle performance and reliability

Installation Notes and Tips

When installing the National differential pinion seal 100727, ensure the housing bore is clean and free of debris. Use appropriate tools to press the seal evenly into place without damaging the fluoro-elastomer material. Verify the seal’s orientation matches the original part to maintain proper sealing function. Lubricate the seal lip lightly with gear oil before installation to reduce initial wear. Follow vehicle-specific service manual instructions for torque specifications and installation procedures.

Quality Assurance and Warranty

National manufactures this differential pinion seal to meet industry standards for durability and performance. The fluoro-elastomer material provides resistance to heat and chemical exposure typical in driveline environments. Part number 100727 is backed by National’s quality control processes to ensure consistent fit and function. Warranty coverage details should be confirmed with the original equipment manufacturer or distributor.