Clutch Fan Question

**kwhizz** · #1 09-01-2007, 06:16 PM

I have a stock Clutch Fan on my 66 Chevelle......It doesn't seem to be working correctly as it seems to freewheel all the time, In traffic the Temp rises and if I shut the car off and turn the Fan by Hand it still freewheels......I took it back to where I bought it and they replaced it with a "New" one....It doe's the exact same thing..........shouldn't there be some Resistance to the fan turning as the Radiator builds heat??

Thanks in Advance

L78steve · #2 09-01-2007, 06:41 PM

Check for air flow in front of rad.Should be pulling hard at full temp.and high idle.And you should hear the fan.

L78steve · #3 09-01-2007, 06:56 PM

Also keep in mind if your clutch is for a latter model with a 195 degree therm.then the clutch won't engage until 210.

**Mr70** · #4 09-01-2007, 06:57 PM

Exactly how hot a temp. are you reaching at idle?
You should be able notice significant resistance,even once the fan is attached to it.
I've been tackling this very same problem with mine this summer.
Stay away from Hayden brand Ken,as they seem to be not as road worthy on Big Blocks.
GM uses a unique fluid dampner that is more sensitive then most,so aim for that first.I found a real good GM parts wholesaler in Wisconsin that carries defunt fan clutches while others say looong discontinued.
How close or distant is your clutch to your radiator,as you may need a spacer,added or removed,or even your belt slipping under duress.

**kwhizz** · #5 09-01-2007, 07:48 PM

Check for air flow in front of rad.Should be pulling hard at full temp.and high idle.And you should hear the fan.

Never any Fan Noise.....That's what bothers me....NAPA guy say's it fine

.......I don't think so.....

Also keep in mind if your clutch is for a latter model with a 195 degree therm.then the clutch won't engage until 210.

Don't know...........

Exactly how hot a temp. are you reaching at idle?

The Needle is usually in the middle (or halfway) and when it sits in traffic it go's to 3/4......and pukes out the radiator......

You should be able notice significant resistance,even once the fan is attached to it.

None.........

How close or distant is your clutch to your radiator,as you may need a spacer,added or removed,or even your belt slipping under duress.

Fan Clutch is 1/2" from the Radiator with a shroud around it......

I think you guy's have answered my question....The Fan Clutch is "New" "Junk"

again.....
Now.....Bottom line.......where can I actually go to buy one that will actually work........???

Thanks for the Input

Ken

**Mr70** · #6 09-01-2007, 07:54 PM

PM sent...

**Mr70** · #7 09-01-2007, 08:52 PM

Yours took the Non pie-plate design fan clutch originally,#3857530 stamped CK,and has been discontinued some 30 years ago.It was superseded by clutch #3916141
But that's good news,as that's the same one the 65 Corvettes used,which means it most likely has been prone to be reproduced,and it has... HERE
There were two manufacturers making this Clutch,Eaton & Sweitzer.
Swietzer is known for the Bi-metallic thermostat,and Eaton the coil thermostat.
That's an Eaton on Ebay.
I have a Swietzer lying around,but it's by no means reliable anymore.
Both off those clutches measured up 2-3/4 deep,6" diameter with a 1-3/4 center.
You don't have to pay that Ebay price yet.Wait until LaborDay weekend is over & I can probably find you one less expensive & in your area.

**kwhizz** · #8 09-02-2007, 07:59 AM

Thanks.............

Ken

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