Fan clutches

[T_F_E]

So when these go bad they usually stop engaging fully right? Do they ever stay engaged? I started mine cold this morning and the fan tore through about 4 rolled up newspapers. I have been getting bad mileagehttp://www.dieselplace.com/forum/showthread.php?t=369183# and the power has seemed down a little bit lately. I also never see temperatures over 180 even without a fan shroud.

Thanks for the help guys,
Mike

 

[hovenga67]

Usually they will stop really easy when they are bad unless the bearings are going bad. Will it turn by hand?
Brent

 

[T_F_E]

Turns by hand but there is quite a bit of resistance

 

[kapnklug]

Ya that's how they're supposed to feel, can turn by hand but not spin freely. I've only seen them go bad by losing all resistance so that the engine overheats

 

[kassim503]

Sometimes the thermostat on it gets stuck and they stay locked all the time. Try starting the truck when its cold and holding a high rev for 30 or so seconds, if during that time the fan dosent slow down or making that loud whoosing noise your fan clutch may be bad.

Also, if you do decide on replacing your clutch, make sure you get the one that looks like yours, there is usually a hd one and a regular duty one. The regular duty one spins the fan slower, while the HD one may lock up too much for your liking.

 

[rlwm211]

In my experience when a thermal clutch fan fails the fan stops engaging and properly cooling the truck. The test is to check the fan with the truck at temperature, but not overheated. With the engine off, spin the fan with your hand and it should stop in less than a revolution. Also check for wobble and any other indication of bearing failure. If the fan bearing fails it can take out your radiator and that can be an expensive proposition.

It is absolutely normal for the fan to run on "HIGH" for a minuite or so when you start out with a cold engine. Typically my fan stays at high until I start driving and the first acceleration it slows down.

RL