A fan clutch consists of a thermostatic spring that is temperature sensitive and controls when the fan clutch is engaged. When your vehicle is moving at slow speeds the clutch is disengaged. But as you move faster the air in the engine heats up and causes the thermostatic spring to expand which engages the clutch. If you are having issues with your fan clutch, it is most likely caused by this spring. But, since you can't just replace the spring, it is necessary to replace the entire fan clutch. There are two different types of fan clutches. One type is attached to the fan with four large bolts, and the other is fastened with one large nut. Both are simple to remove, but to remove the fan clutch with the single large nut, you will need a specialized tool. You can usually rent or purchase this type of tool from any auto parts store.
Step 1- Remove the Fan Shroud
Since every engine is different, you may or may not need to take every step outlined in this article. It is meant as a general guideline you can follow, but you may need to alter the steps to fit your engine type. Now locate the fan in the front of the engine compartment. You will first need to remove the fan shroud. The fan shroud is the cover over the fan. There will be several bolts that attach the fan shroud, you need to remove these before the shroud will be free. You may need to remove the top radiator hose as well to remove the fan shroud. If so, you will need to drain your coolant system as well. Lift the fan shroud up and out of the engine compartment and set aside.
Step 2- Remove the Fan
Now that the fan shroud has been removed, you need to determine how your fan is attached. If there are four large bolts, then you just need to use the appropriate wrench and remove each of the four bolts. If your fan is attached using one large nut, then you will need to use a special pulley locking tool to keep the pulley from turning while you are removing the nut. One alternative to the pulley locking tool is using a screwdriver to keep the bolts in place as you loosen the nut. This method is more difficult, and can cause damage to your bolts, but it may be your only option if you cannot locate a pulley locking tool. Once the bolts and/or nut has been removed, grasp the fan and move it forward with a gentle side to side motion. Remove the fan and place on a sturdy work table to continue the repairs.
Step 3- Remove the Clutch
Place the fan on your work table with the shaft facing you. In the center of the fan assembly there will be 4 large bolts that hold the clutch to the fan. Simply remove these bolts and you have removed the fan clutch. You can reinstall the new one using these same methods in reverse.