InMotion WS100085 Engine Crankshaft Seal - Rear

Rear Differential Pinion Seal for GM Applications

The InMotion WS100085 is a rear differential pinion seal built with PTFE for a precise sealing surface and dependable fluid control. It is engineered to help keep contaminants out of the differential pinion area while maintaining a tight seal at the shaft and housing interface.

Compatible with a wide range of Chevrolet, GMC, Cadillac, Buick, Pontiac, Saab, Hummer, Isuzu, and related rear differential applications, this seal is a direct-fit service part for many GM trucks, SUVs, and performance cars. The WS100085 is a practical choice when servicing a leaking rear pinion seal on vehicles such as the Chevrolet Silverado 1500, GMC Sierra 1500, and Chevrolet Corvette.

Key Features

• PTFE sealing material for low-friction, precision sealing performance
• Inside diameter: 3.858 in.
• Outside diameter: 4.54 in.
• Housing bore: 4.525 in.
• Shaft diameter: 3.858 in.
• Thickness: 0.403 in.
• Width: 0.492 in.
• Rear position application
• Part number WS100085 for easy identification

Detailed Description

InMotion WS100085 is designed as a rear differential pinion seal for GM platforms that require a precise PTFE seal at the pinion shaft. Its dimensions are specified for accurate fitment at the housing bore and shaft diameter, helping maintain a secure barrier against moisture, road debris, and gear oil leakage. This makes it a strong service option for rear differential maintenance on vehicles including the Chevrolet Silverado 2500 HD, GMC Yukon, and Cadillac Escalade.

This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

What It Helps Address

• Rear differential gear oil seepage at the pinion seal
• Contamination entering the differential pinion area
• Seal wear from age, heat, and driveline use
• Maintenance needs on GM rear differential service jobs
• Noise or driveline concerns related to low differential fluid levels

Installation Notes and Tips

Confirm the rear differential application, shaft diameter, and housing bore before installation. Clean the sealing surface thoroughly and inspect the pinion yoke and surrounding components for wear or scoring before fitting the new seal. Proper installation technique is important to preserve seal integrity and prevent repeat leaks. Verify vehicle-specific rear differential requirements for the Chevrolet Silverado 1500, GMC Sierra 1500, or other listed applications before service.

Quality Assurance

InMotion manufactures this seal with precision-focused construction and high-quality materials to support reliable differential sealing performance. Part number WS100085 is identified for accurate ordering and service matching.