mazdaverx713b

iTrader: (91)

i've got a wasted and almost permantly locked fan clutch on my 82 GSL. i've got about a dozen more bad or nearly bad fan clutches in my garage. what causes the fan clutch to lock up and remain in the locked position? is there any way to repair them or soak them in a fluid that would allow them to become functional again?

ray green

iTrader: (14)

Funny, I have the opposite problem, about a half a dozen fan clutches that don't lock up. I've finally come to the conclusion that this is just the way they are supposed to work, stiffening when hot but never really locking up.

This includes one that I removed from one of my GSLs because it was doing the aircraft prop thing, locking up and blowing like crazy all the time. But now I can't even figure out which one it was, apparently it fixed itself while being stored in the shed.

Anyway I did notice while messing with fan clutch issues a few months ago that the ones that are a little stiff loosen up if you work them back and forth real fast for a few minutes.

Or, if it's still on the car, you can spin it backwards for a while with the engine off, then CAREFULLY (don't loose a finger) keep it from spinning while the engine is idling.

I actually tried this with one of my fans just to test the way the tension changes, but then thought better of it because I thought I might be damaging the fluid. In your case, with nothing to loose (except you finger), it might work to your advantage.

The theory would be that the temperature sensitive fluid that provides the friction to engage the fan at higher temp has gelled a bit and needs to be broken up, or something like that.

I don't know if it would work for you, but it would be an easy and inexpensive thing to try.

Ray

drift7drift

put a e-fan on...

Jeff20B

iTrader: (13)

You can usually slow down a clutch fan with your finger and hold it like ray green says. Be careful.

mazdaverx713b

iTrader: (91)

do you guys think that it'll help by holdong the fan whith teh engine on? when i do this afternoon, i'm going to to ahead and use a breaker bar to hold it instead of my finger.

trochoid

iTrader: (6)

Use a broom instead, the working end, not the handle.

ray green

iTrader: (14)

Yeh definitely use a broom, I was kidding about the finger stuff. And if you can't hold it back without too much trouble I'd give up on the idea

flight_of_pain

they never totally lock up, plastic fans at 7k rpm=BAD. the fluid just becomes more viscous as the temp inreases.


isaac

7aull

iTrader: (2)

I think the idea of the clutch fan is: after a certain rpm is reached, the clutch allows the fan to stay at a slower speed than the engine... I know I read somewhere that if you put a timing gun (properly attached) on the fan you should be able to tell if its "breaking away" from the revving engine speed as it should. I believe the rpm was 2500 or 3000. ook. sorry. This is where a LITTLE info can be a dangerous thing. Does this ring a bell with anyone? Since clutch fans are so widely used, this shold be easily Googled...
Stu Aull
80GS
Alaska

mazdaverx713b

iTrader: (91)

i ended up swapping the fan clutch out with a good one(my last 81-83 fan clutch) and everything is fine. there has to be some way to repair these buggers...

Bigmotoxer

This is what I think I know about clutch fans=
The fluid in the clutch is to allow the engine to rev up quickly under instant accelleration w/out having to turn the whole weight of the fan/air/ect. Fan will quickly catch-up and run top speed w/the engine at idle speeds and normal driving until airflow through the radiator(air hitting the front side of the fan)will affect the fan speed as the mph increase actually slowing the fan because now you have natural airflow...the number of fins and the pitch of the fins play a big part in this. I think it's whole principal is to try and limit the drag on the engine like when reving or turning on A/C, ect...at not to actually block airflow at high speeds/RPM's.
I know that if you replace a clutch fan w/non-clutch fan(depending on the # of fins and pitch) that at higher speeds for longer intervals can/will actually block airflow through radiator and across engine to actually cause higher temps(happened to me back in 1990 on my 83' GrandPrix).
I thought when they go bad that the signs of this will be a loose clutch(spins too feely never spinning fast enough to draw enough air under normal driving)but I know that if they go beyond that point, to the point of being really bad they can lock up although that's never happened to me.
IMO