Four Seasons 36977 Engine Cooling Fan Clutch

Four Seasons 36977 Fan Clutch Overview

The Four Seasons 36977 engine cooling fan clutch is a standard-duty thermal replacement built for reverse-rotation applications. It is a new, non-electronic aluminum unit that meets or exceeds OEM requirements and is performance rated for dependable cooling control.

Use this Four Seasons fan clutch for reverse-rotation cooling systems on select Chevrolet S10, Chevrolet S10 Blazer, GMC S15, GMC S15 Jimmy, GMC Sonoma, Chevrolet Astro, and GMC Safari applications with air conditioning.

Key Features

• Brand: Four Seasons Fan Clutch
• Part number: 36977
• Type: thermal, standard-duty
• Use type: standard
• Material: aluminum with raw aluminum finish
• Non-electronic design
• Reverse rotation (REV)
• Flange mounting style
• 4-bolt / 4-hole mounting pattern
• Fan bolt circle: 3.25 in. / 82.6 mm
• Mount diameter: 2.43 in. / 62 mm
• Overall height: 3.8 in. / 96.5 mm
• Meets or exceeds OEM specifications
• Performance rated

Product Details

The Four Seasons 36977 fan clutch is built for vehicles that use a reverse-rotation, standard-duty thermal fan clutch with a rear-mounted fan and air conditioning. Its aluminum construction, flange mount, and 4-bolt pattern support a direct-fit style replacement for the listed applications. This part cross-references Gates 22147 and Dorman - HELP 47239 for the same application. Four Seasons 36977 is a practical choice when replacing a worn fan clutch on Chevrolet S10 and GMC Sonoma cooling systems that rely on thermal fan engagement for engine temperature control.

Common Problems This Part Can Address

• Engine running hotter than normal at idle or low speed
• Fan clutch not engaging correctly in reverse-rotation cooling systems
• Reduced airflow through the radiator and condenser
• Cooling fan noise caused by a worn clutch mechanism
• Inconsistent temperature control in AC-equipped trucks and vans

Installation Notes and Tips

Verify reverse rotation, flange mount dimensions, bolt circle, and pilot measurements before installation. Confirm the vehicle uses the thermal fan clutch configuration listed for your year, make, and model, especially on Chevrolet S10, GMC Sonoma, and related applications. Inspect the fan, pulley area, and surrounding cooling components for wear before installing the new clutch. Mounting hardware is not included.

Quality Assurance

Four Seasons 36977 is a new replacement fan clutch that meets or exceeds OEM specifications and is performance rated for standard-duty service. It is designed for confirmed fitment on 1987-1993 Chevrolet S10, 1987-1988 Chevrolet S10 Blazer, 1988-1990 Chevrolet Astro, 1987-1990 GMC S15, 1987-1988 GMC S15 Jimmy, 1988-1990 GMC Safari, and 1991-1993 GMC Sonoma applications.