Fan Clutch

[rdm]

Question for Peter. How do you tell if the fan clutch is not working properly. I have been told that the clutch deterioates over a period of time and should be replaced every 3 to 5 years. What is your experience peter.

[PeterH-350LE]

Once temperatures reach the 80's, you should hear the fan clutch engaging. Typically it will engage quiet frequently in city traffic, during highway travel it may engage every 30 minutes for a duration of several minutes.
Depending on the type of fan clutch (heavy duty versus light duty), the engine noise will change noticeably, also a slight loss in engine power will be experienced.
To check if the fan clutch is operating, rotate the fan blade by hand on a cold engine. If it spins freely, the fan clutch is completely dead.
If it resists spinning, the clutch is working, but may not be as efficient as it could be.
I replaced my fan clutch, because I had easy access. My old one was working, but the new one engages more often, which is telling me that it was due time to replace it.
Getting a fan clutch replaced while on the road, is an expensive undertaking.

[LKappenman]

Our 1983 Turbo Diesel 310 does not have a fan clutch and we are sure that maybe why occiasionally it boils over on a long pull is there a brand that is better than others? Is this a home project or should it be down professionally?

[PeterH-350LE]

Not knowing much about diesels, I not sure what applies to your situation.
Besides aiding in cooling, the fan clutch also is a 'spacer' moving the fan blades in the proper position relative to the fan shroud.
The fan clutch is mounted to the waterpump and the fan blades are mounted to the clutch, moving the blades 1 1/2" from the pump towards the radiator. Are your blades mounted directly to the waterpump?
Replacing the fan clutch is easy, but depending on your vehicle, hard to get to.
Since the fan is mounted to the clutch, it is in most cases impossible to remove both with the fan shroud in place. To remove the fan shroud, the radiator has to be pulled.
It is possible to pull the fan clutch, by first unbolting fan from the clutch and then unbolting the clutch from the water pump. Now the clutch can be moved forward and out, leaving the fan hanging loose. To tighten and untighten any of the bolts or nuts, use a flat head screw driver wedged between two bolts, do not use the fan blades for that purpose!