How Does A Fan Clutch Fail — What Happens Next?
There are two main ways in which a fan clutch can fail, either fail to engage at all or permanently engage and become stuck. Both of these situations can cause problems with overall engine performance, but failing to engage is much more detrimental to engine health. If the system cannot engage properly, engine temperature can sore to damaging extremes and can cause radiators and other cooling systems to fail. What Are the Root Causes of Failure In A Fan Clutch?
In any mechanical failure there can be a number of variables that can be a potential root cause. In terms of the lubricant itself there are five main ways lubricant selection can become a potential failure point.
- High Loads - Lubricant selection is not viscous enough to handle consistent high loads causing inconsistent lubricant film, excessive noise, heat generation, and premature bearing wear.
- Low Loads – Lubricant selection is too viscous and the applied load is not enough to work the grease, leading to noise, heat generation, and premature bearing wear, primarily from skidding.
Incorrect Fill Factor / Fill Rates:
- Over - Temperature - The lubricant selected cannot withstand the operating temperature range and leads to fluid breakdown, deposit buildup and ultimately can result in total bearing failure.
- Under - Temperature - The lubricant selected cannot function at extremely low temperatures. This most commonly affects geographies with intense winter weather but can result in noise, irregular lubricant film, and wear patterns in the bearing
- Incorrect Fill Factor - Addition of too much or too little grease — Resulting in stuttering and inconsistent performance for the part. This can cause bearing damage and extreme noise generation.
There are a multitude of other mechanical root causes of failure, but lubricant selection is an important first step and it's critical to keep all five of these points in mind. Krytox™ Lubricants have proven over many years that the correct lubricant for viscous fan clutches used in Automotive, Light Duty, and Off Road trucks greatly reduces bearing failure due to lubrication.