Four Seasons 36786 Engine Cooling Fan Clutch

Four Seasons 36786 Fan Clutch Overview

Four Seasons 36786 is a thermal engine cooling fan clutch built for severe-duty and truck fan drive applications. It uses an aluminum construction, reverse rotation operation, and a non-electronic design to support cooling performance in demanding service conditions.

Compatible With 2001-2005 Chevrolet Silverado 2500 HD, 2001-2005 Chevrolet Silverado 3500, 2001-2005 GMC Sierra 2500 HD, 2001-2005 GMC Sierra 3500, 2006-2009 Chevrolet Express 2500, 2006-2009 Chevrolet Express 3500, 2006-2009 GMC Savana 2500, and 2006-2009 GMC Savana 3500.

Key Features

• Four Seasons Fan Clutch line for engine cooling service
• Part number 36786
• Thermal, non-electronic clutch design
• Severe-duty and truck fan drive style
• Reverse rotation operation
• Aluminum housing with raw aluminum finish
• 4-bolt, 4-hole mounting layout
• Meets or exceeds OEM requirements
• Performance rated for demanding cooling applications

Product Details

This Four Seasons fan clutch is engineered with a 7.4-inch maximum diameter, 4.27-inch overall height, 1.75-inch distance from clutch to mounting flange, and a 1.86-inch mount diameter. Additional dimensions include a 1.42-inch pilot diameter, 0.78-inch pilot depth, and a 3.81-inch fan bolt circle. The clutch uses an M8 x 1.25 hole thread pattern and a hex mounting type.

Four Seasons 36786 is a direct-fit style replacement for reverse rotation cooling systems found on Chevrolet Express, GMC Savana, Silverado HD, and Sierra HD applications. This part cross-references Gates 22617 for the same application.

What It Helps Address

• Engine cooling fan engagement issues
• Excessive fan slip in severe-duty service
• Cooling performance loss under load or high heat
• Noise or inconsistent fan drive operation
• Replacement needs for worn thermal fan clutch assemblies

Installation Notes and Tips

Verify reverse rotation fan clutch requirements before installation. Confirm the fan bolt circle, pilot dimensions, and mounting style match the vehicle’s cooling fan assembly. Mounting hardware is not included, so reuse or source the correct hardware separately as needed. Always inspect the fan blades, water pump area, and surrounding cooling components during service.

Quality Assurance

Four Seasons 36786 is a new, performance-rated fan clutch that meets or exceeds OEM specifications for the listed applications. Its severe-duty thermal design is intended for truck and van cooling systems that require dependable fan drive control.