Four Seasons 36951 Engine Cooling Fan Clutch

Four Seasons 36951 Severe Duty Fan Clutch

The Four Seasons 36951 engine cooling fan clutch is a thermal, reverse-rotation unit built for severe-duty cooling demands. It is a non-electronic aluminum fan clutch with a flange mount, made to meet or exceed OEM requirements for the listed Ford, Dodge, and Mercury applications.

Four Seasons Fan Clutch line products are built for direct-fit cooling system service, with application-specific sizing and rotation to match the factory fan drive setup. This part number 36951 is a severe duty truck fan drive style for vehicles that need consistent airflow control under load.

Key Features

• Thermal, non-electronic engine cooling fan clutch
• Severe duty D-style truck fan drive design
• Reverse rotation (REV) configuration
• Aluminum construction with raw aluminum finish
• Flange mount with 4 bolt holes and 4 mounting holes
• Fan bolt circle: 3.25 in. (82.6 mm)
• Mount diameter: 2.58 in. (66 mm)
• Overall diameter: 6.45 in. (163.8 mm)
• Overall height: 3.83 in. (97 mm)
• Meets or exceeds OEM specifications
• Performance rated for severe use

Detailed Description

Four Seasons 36951 is an engine cooling fan clutch engineered for reverse-rotation applications that use a thermal clutch to regulate fan engagement. With a 6.45-inch clutch diameter, 1.8-inch distance from clutch to mounting flange, and 0.63-inch pilot dimensions, it is sized for the factory cooling package used on select Ford F-250, Ford F-350, Ford Bronco, and Ford E-Series vans, along with other listed applications. The severe-duty design supports trucks and vans that see higher cooling loads, including Ford F-150 and Ford E-150 Econoline fitments with AC.

This part number 36951 is also listed for 1990-1991 Dodge Dakota and 1984-1985 Ford LTD applications, plus 1984-1986 Mercury Grand Marquis. If you are replacing a worn fan clutch on a Ford Bronco, Ford F-250, or Ford E-350 Econoline, this thermal reverse-rotation unit provides the correct mounting style and fan drive layout for the specified vehicles.

This part cross-references Gates 22146 for the same application.

What It Helps Address

• Engine overheating caused by a weak or slipping fan clutch
• Reduced fan engagement at idle or low road speed
• Cooling performance loss under towing or heavy-load conditions
• Noise or vibration from a worn mechanical fan drive
• Incorrect replacement on reverse-rotation cooling systems

Installation Notes and Tips

• Verify reverse-rotation fan drive requirements before installation.
• Confirm flange mount, bolt pattern, pilot diameter, and overall height against the original unit.
• Use the listed vehicle notes to match AC and severe-duty cooling configurations.
• Mounting hardware is not included.
• Inspect the fan blade, water pump, and shroud while servicing the clutch.

Quality Assurance

Four Seasons 36951 is a new part that meets or exceeds OEM specifications and is performance rated for severe-duty use. Its application-specific design supports direct replacement service on the listed Ford, Dodge, and Mercury vehicles, including Ford F-250, Ford F-350, and Ford Bronco fitments.