InMotion WS3638 Manual Transmission Input Shaft Seal

Manual Transmission Input Shaft Seal for Ford, Jeep, and GM Applications

InMotion WS3638 is a manual transmission input shaft seal built to maintain a tight barrier at the transmission opening. It uses polyacrylate material and precise dimensions to help keep contaminants out and fluid in, supporting dependable operation in a wide range of Ford, Jeep, Chevrolet, GMC, Dodge, Pontiac, Mercury, and Buick manual transmission applications.

Key Features

• Part number: WS3638
• Polyacrylate construction for sealing performance
• Outside diameter: 1.63 in. / 41.4 mm
• Housing bore: 1.62 in. / 41.3 mm
• Shaft diameter: 1.125 in. / 28.6 mm
• Thickness: 0.18 in. / 4.7 mm
• External marking: NAK SLR 1.125 1.624 0.190 3

Detailed Description

This manual transmission input shaft seal is engineered for applications that require a secure seal around the input shaft area. By helping block moisture, dirt, and other contaminants, WS3638 supports cleaner internal operating conditions and helps reduce the chance of fluid leakage. It is a direct-fit style seal for many older manual transmission platforms, including Ford Mustang, Ford Bronco, Jeep CJ7, and Chevrolet G20/G30 applications listed in the fitment data.

With a 1.125-inch shaft diameter and 1.63-inch outside diameter, this seal is sized for specific transmission housings and should be matched carefully to the transmission code noted in the fitment list. InMotion WS3638 is a practical replacement choice for restoration work, drivetrain service, and maintenance on vehicles that rely on a properly sealed input shaft area.

What It Helps Solve

• Transmission fluid seepage at the input shaft area
• Contamination from road debris and moisture
• Wear caused by degraded or hardened sealing surfaces
• Service issues on older manual transmission vehicles
• Leak-related drivability concerns during routine drivetrain maintenance

Installation Notes and Fitment

Compatible With many manual transmission applications across 1965-1996 model years. Fitment examples include:

• Fits 1983-1996 Ford Mustang, with Tremec 3550 Transmission
• Fits 1983-1986 Jeep Cherokee, with Tremec 176FT Transmission
• Fits 1976-1982 Chevrolet G20, N/A
• Fits 1976-1982 Chevrolet G30, N/A
• Fits 1975-1980 Dodge Ramcharger, with Tremec 150T Transmission
• Fits 1965-1973 Ford Mustang, with Tremec 170F Transmission

Confirm the transmission code and seal dimensions before installation. Clean the bore and shaft area thoroughly, and inspect the sealing surface for scoring or wear that could affect seal performance. The part number WS3638 should be verified against the vehicle’s transmission specification, especially on older Ford, Jeep, and GM platforms with multiple gearbox variants.

Quality Assurance

InMotion manufactures this seal with precision-focused construction and high-quality materials to support reliable sealing performance in manual transmission service. The polyacrylate sealing material is selected for durability in drivetrain applications where contamination control and leak prevention are important.