clutch fan rebuild

[John O.]

Hi all

I'm not sure but when I start my 327 250 HP 62 vette motor I noticed that the beginging of the cranking and as soon as it starts,, the fan does not seem to be turning as fast as the cranking until the engine is running.When I turn the fan by hand, it seems to spin easy. Should'nt the fan be alittle harder to turn by hand. I noticed my temp gauge was going up.The car is not drivable yet. This is while it's sitting in the garage.Does the clutch need rebuilding? Does anyone know who does them? Your help will be appreciated.

Thanks...John

[Joe C.]

Re: clutch fan rebuild

http://www.gate.net/~foliva

[Eugene B.]

Re: clutch fan rebuild

John,
A good way to evaluate your clutch fan is to observe the fan when you turn the engine off. With hood up and engine idling, turn off engine and observe fan. The fan should stop within approximately five revolutions. If the fan continues to free wheel, it's time to send it to Fred.

Hope this helps.

Regards,
Gene

[John O.]

Re: clutch fan rebuild

Hi Gene.

Who is Fred? Do you have contact info for him?
Thanks Guys for your help.

John

[Tracy C.]

Re: clutch fan rebuild

John,

What you see with your fan isn't cause for alarm just yet. The fan contains a temperature sensitive spring that engages the fan when the surrounding environment warms it sufficently.

If it continues to spin freely after you shut the engine off as previously posted then maybe it needs a rebuild.

Fred's Contact information is at the link provided by Joe.

tc

[Mike E.]

Re: clutch fan rebuild

All the above advice is excellent--but, make sure the engine is warm and good warm air has been brought past the fan before you shut off the motor--otherwise, you'll not get the proper sense of what's going on. It is built to free-wheel when the air passing it is cold--that's how you get less drag and less noise, which was the reason they went to the clutch fan in the first place.

[Wayne K.]

Re: clutch fan rebuild

Gene,

I have a 67 L79 and my fan turns kind of hard. When fully warmed up and I turn the motor off at idle the fan only turns about 2 additional revolutions. The clutch has been replaced by a previous owner. I never gave this much thought until reading your post. I have never had a problem overheating. Do you think my clutch could be bad?

Wayne

[Mike E.]

Re: clutch fan rebuild

That actually means that your clutch is working very nicely--better than the 5-revolution tolerance. More than 5 means get it rebuilt--less than 5 means you're in great shape.

[John O.]

Re: clutch fan rebuild

Thanks guys

I did start the motor and I only let it run 1 minute and turned it off. The fan kept spinning. At least 10-15 revolutions. So I do believe it needs rebuilding.

Thanks again...John

[John O.]

Re: clutch fan rebuild

Thanks for the info Mike. I will let the motor warm up awhile then shut it off and see if the fan stops quicker.

Thanks...John

[John H.]

Re: clutch fan rebuild

John -

That's not enough to affect the thermostatic coil on the clutch; the engine (and the radiator) need to be at full operating temperature so the fan pulls HOT air through the radiator to impinge on the front of the clutch where the thermostatic coil (or plate) is. That's a bi-metallic coil (or plate), and it responds to the heat of the air exiting the radiator in order to adjust the internal orifice that controls the amount of clutch lockup provided.

[John O.]

Re: clutch fan rebuild

Hi John

If I get the temperature of the motor to what it is supposed to be, then shut it down, should the fan stop within 5 revolutions? If it spins more, does that mean I need a rebuild?

Thanks...John

[Craig S.]

Re: clutch fan rebuild

That's basically the idea. Some of the suppliers still had some of the most recent GM (Eaton) version of the clutch at least right around Carlisle time last year. I think Joe Lucia indicated this part had gone extinct in the GM system near that time last year. If you can get one of those for driving I would and rebuild the original for show. It is easy to change.....my plan is to use my NOS Schweizter for show and the GM recent version for driving.....Craig