Precision Parts 5778 Differential Pinion Seal

The Precision Parts 5778 is a differential pinion seal engineered to prevent gear oil leakage at the pinion shaft on rear-wheel-drive axle assemblies. Made from polyacrylate rubber (ACM), this seal delivers strong resistance to extreme-pressure (EP) lubricants and low swell in hydrocarbon fluids, making it well-suited for demanding driveline environments.

Key Specifications:

• Inside Diameter: 1.552 in (39.42 mm)
• Outside Diameter: 3.165 in (80.39 mm)
• Width / Thickness: 0.645 in (16.38 mm)
• Seal Material: Polyacrylate Rubber (ACM)
• Design Type: Spring-loaded, multi-lip
• Series: 5000
• Temperature Range: -20°F to 300°F (-29°C to 149°C)

Key Features:

• Designed to meet or exceed OEM specifications for fit, form, and function
• Spring-loaded multi-lip design ensures consistent sealing contact against the pinion shaft
• Prevents differential oil leaks that can cause driveline damage and component wear
• Protects internal differential components from contamination
• Maintains proper lubrication levels within the differential housing
• Sold as a single seal

The Precision Parts 5778 pinion seal is a direct-fit replacement for a wide range of domestic and import vehicles. Cross-references to National 5778, NTN NS5778, and other industry-standard part numbers.