Fan Clutch

Why GMB Fan Clutches?

Not all fan clutches are the same. Here’s what makes our fan clutches stand out.

High-Quality Carbon Steel Flange (Ball Bearing)

GMB uses high-quality carbon steel that is made to withstand high impacts, have high billet density, and have high deformation resistance. Every GMB Ball Bearing is machine press-fitted to the main case using the proper force range.


Inferior lower-grade metals are more susceptible to premature wear, deformation, and shearing, which causes excessive vibration, overheating, damage to other engine components, or even catastrophic failure. Improperly press-fitted Ball Bearings utilizing inadequate force can result in the bearing separating from the case, also causing vibration, overheating, and failures.

Fan Clutch

Precision OEM-Spec Fan Clutch Components

GMB Fan Clutch components are manufactured to match the exact OEM spec materials: high-quality cold rolled steel, aluminum, and carbon steel. Each component is precision measured using state-of-the-art technology to be dimensionally correct, with 99.99% accuracy and strict tolerance limits.


Using materials other than exact OEM-spec materials or having inaccurate dimensions with loose tolerances can cause shaft rupture, bearing failure, fan ceasing, compromised air flow rates, oil leakage, and/or inadequate performance.

Precision OEM-Spec Test Standard

GMB Fan Clutches are manufactured to match the exact OEM performance that’s intended for the vehicle. Each fan clutch is also precision tested using rigorous standards to maintain 99.99% accuracy and strict tolerances.


Inaccurate design without testing standards could cause compromised airflow rates at varying RPM ranges, inadequate coolant system pressure, overheating conditions, or even water pump cavitation.

Proprietary OE Fixed Design

GMB has supplied and worked with OEMs for years and knows most fan clutch issues relate to noise or oil leakage. To prevent oil leakage, GMB Fan Clutches include an oil seal on top of the rotor. GMB also revised the design of the oil seal from a single oil seal to a double oil seal and expanded the return hole to retrieve all oil from the rotor.


Low-quality products are not made by reverse engineering, nor do they adhere to OE standards. GMB OE Fixed Designs are engineered solutions to correct OE parts’ issues and limit the defect rate for the whole assembly, not just the components.

Educate Your Customers About Preventative Maintenance!

Preventative maintenance is the key to maximizing the performance and durability of any fan clutch. Here’s a list of maintenance tips to share with your customers:

  1. Ensure the thread surfaces of the Fan Clutch and Water Pump are clear of any debris.
  2. Screw the Fan Clutch onto the Water Pump threads ensuring the threads interlock properly.
  3. Torque the Fan Clutch to the correct specification, following the manufacturer’s recommendation.
  4. Use tools specifically designed for the Fan Clutch to ensure the pulley does not move while turning the threaded nuts.