Fan Clutch question....
Thread Starter
Melting Slicks
Joined: Jan 2003
Posts: 2,713
Likes: 31
From: Shreveport LA
LA Events Coordinator
Fan Clutch question....
How do you know if you fan clutch is working properly? What's it's supposed to do when you turn off the engine? What about when you turn the fan by hand when the engine is cold...should you feel any resistance? I'm sure it has been discussed in the past but I've looked throughout the forum and can't find any direct info....
Melting Slicks
Joined: Aug 2003
Posts: 2,135
Likes: 2
From: Dayton Oh
The idea is that the fan clutch spins freely at low temps and then engages at high temps. I had mine go at a few months ago and the only way I figured out the problem vs the water pump or therm stat was that the clutch had a lot of slop in it.
Drifting
Joined: Mar 2008
Posts: 1,900
Likes: 3
From: Nixa Missouri
How do you know if you fan clutch is working properly? What's it's supposed to do when you turn off the engine? What about when you turn the fan by hand when the engine is cold...should you feel any resistance? I'm sure it has been discussed in the past but I've looked throughout the forum and can't find any direct info....
He told me that whether the engine is hot or cold, if you hand spin the fan(engine off) and it rotates 2 full revolutions then it's due to be replaced. This was his rule of thumb. We were talking about this the other day and I had asked him the same question. The reason I had asked him about the fan clutch is that mine is still original and I was finding it had to believe that it was still in good working condition. I hand spun the fan blade and it doesnt even make one revolution. Damn they built good **** back in the 60's & 70's.
So I would think that when you have your car running and turn off the engine and the fan continues to spin alot then you might be due for a change.Hope this helps.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
If you decide to buy a new one here is one that you can depend on.
GM#88961768 This clutch moves a ton of air when you need it.It is recommeded to replace the water pump and clutch at the same time especially if the pump or the clutch had wobble to it.
GM#88961768 This clutch moves a ton of air when you need it.It is recommeded to replace the water pump and clutch at the same time especially if the pump or the clutch had wobble to it.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
The fan should not spin freely at all by hand hot or cold. You can turn it but it will not spin. Unless its bad. When the engine is cold and running, shut it off and it should spin about a half turn or less.
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Le Mans Master
Joined: Aug 2006
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
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Clutch fan.
The job of the clutch fan is to move as much air as possible at high coolant temps and to relax at normal temps or when over 3500 RPM. Hot or cold the fan should stop in 1 or 2 seconds when you turn the motor off. With the motor off the fan should have a lot of resistance and not turn 1/2 a revolution by hand. PG.
Burning Brakes
Joined: May 2006
Posts: 763
Likes: 0
From: FBO Florida
Seriously though I like the above advice in conjunction with the old spin test.
