Four Seasons 36900 Engine Cooling Fan Clutch

Four Seasons 36900 Fan Clutch Overview

Four Seasons 36900 is a standard duty thermal engine cooling fan clutch built for reverse rotation applications. It is a new, non-electronic aluminum fan clutch with a flange mount, made to meet or exceed OEM requirements for the listed Chevrolet and GMC trucks and vans.

Compatible With 1987-1993 Chevrolet S10, 1987-1989 Chevrolet S10 Blazer, 1987 Chevrolet Astro, 1987-1993 GMC Sonoma, 1987-1990 GMC S15, 1987-1989 GMC S15 Jimmy, and 1987 GMC Safari applications that use a reverse rotation, front-mounted fan setup without A/C.

Key Features

• Four Seasons fan clutch, part number 36900
• Thermal, standard duty design for engine-driven cooling fan control
• Reverse rotation configuration for the listed applications
• Aluminum construction with raw aluminum finish
• Flange mounting style with 4 bolt holes and 4 mounting holes
• Non-electronic design for direct mechanical operation
• Meets or exceeds OEM specifications
• Performance rated for cooling system service
• Clutch type A - 5" & 6" import

Product Details

The Four Seasons Fan Clutch line focuses on replacement cooling components for vehicles that rely on mechanical fan engagement to manage engine temperature. This Four Seasons 36900 unit uses a thermal design to regulate fan drive based on operating conditions, helping maintain consistent cooling performance in the correct reverse rotation setup. With a 5.65-inch maximum diameter, 2.69-inch overall height, 2.7-inch mount diameter, and 5.03-inch fan bolt circle, it is built around the dimensions required by the listed Chevrolet S10, GMC Sonoma, GMC S15, and related platforms. This part cross-references Monroe Shocks & Struts (e.g., 5529) for the same application.

What This Part Helps Address

• Engine overheating caused by a worn or weak fan clutch
• Delayed fan engagement in thermal cooling systems
• Reduced airflow at idle or low vehicle speed
• Noise or inconsistent operation from a failing mechanical fan clutch
• Cooling performance loss on reverse rotation fan applications

Installation Notes and Tips

• Verify reverse rotation, flange mount, and 4-bolt configuration before installation.
• Confirm the vehicle uses a front-mounted fan and the listed no-A/C application notes.
• Inspect the fan, water pump area, and mounting surfaces for wear before replacing the clutch.
• Mounting hardware is not included.
• Use the part number 36900 and the vehicle-specific fitment notes to confirm application match before service.

Quality Assurance

Four Seasons 36900 is a new replacement fan clutch built to meet or exceed OEM specifications for the listed applications. The aluminum construction, thermal operation, and standard duty design support dependable cooling system service in compatible Chevrolet and GMC models.