Well, once again I jump in with a Ford story.......
When I ordered my '89, among lots of the custom packages was the Supercooling package. Bigger radiator, oil cooler, power steering cooler, and bigger fan and heavy duty clutch to handle the extra fan load.
After I got it out of the truck shop where they modified it, I was driving it down hwy 231, the main 4 lane headed out of town. Kinda a cool day, I was in the right lane, and heard a semi coming up along side.
But, he did not pass. I started checking my mirrors, and there was no one there.
Then it sounded like the truck had slowed down or turned off.
Finally realized it was the fan clutch. With the big fan, when it engaged, it was loud. I could watch my temp gauge, and it would ease up slightly, I would hear the fan kick in, and it would ease back down then the fan would quiet down.
I quickly got used to it.
Many years later, I was stuck and winching myself out. Truck started running hot. Got out and checked. The fan was just freewheeling on the shaft.
I had not noticed it when driving because the air flow was enough to keep it in range.
I had some strong cord in the toolbox. Tied it around the base of one of the fan blades, wound it several times tightly around the shaft in the opposite direction of rotation.
In other words, so that it would tighten when the motor was running. Tied it back to the fan, and it kept things cool until I could winch out. Made sure I did not rev the engine very fast until I was out.
Went to the parts store, bought a fan clutch for that model truck. I don't think I ever heard it kick on. It lasted about a week and a half, then started leaking oil.
Got another one under warranty, not quite a week before it started freewheeling.
Saw the same parts guy, he said they must have gotten a bad batch. Had a sudden thought. I asked him if they showed a fan clutch for my truck with super cooling package.
Sure enough, different part number, much heavier clutch. Not sure, but I think it might be the same one on there now.
I did figure out why the first one failed. I was at my hunting camp and the river was up. Going in and out, the fan would go underwater for about 1/4 mile at a time. I think the internal oil pressure from the stalled fan just blew the seal.
If yours is roaring all the time, I suspect that its not because of the heavy duty part, its probably defective. Like they said, when the oil is stiff and cold, and has settled out into both sides of the clutch, its normal for it to blow for a few seconds at startup. But, with the fan thermostat closed, its supposed to pump all the oil into the reserve side of the clutch and not leave much to hit the stator.
When the radiator air heats up, the thermostat moves, and opens a port from the reserve side to the active side. So as the stator pumps the oil back into the reserve side, the resulting friction causes the fan to turn closer to belt speed. The warmer the air, the larger the port, and the more oil it sees.
I would run the truck until it gets as warm as it can, stop the engine and try to spin the fan right away. It should not freewheel, but you should get almost a full turn after you spin it by hand.
If it stops as soon as you stop pushing it, and the clutch is fairly warm, its a bad clutch, not too big a one.
EDIT: Actually I got that wrong. I would crank the truck, run it a few minutes, not long enough to warm up much, then check the fan.
With the engine still cool, and the fan clutch in running mode, it should be real easy to spin. You have to run it long enough to pump the oil where it should be, then it should spin easily.
The heavy duty part is mostly for bigger fans to handle the load, not lower temps. One designed for a bigger fan might have some increased resistance when hot, but not that much.
