How can you tell if a fan clutch has gone bad? (no Far Side references please) I spotted some oil leaked between the shaft and the clutch, but can you tell anything by just spinning it? Mine spins freely when it's parked, shouldn't there be some effort there?
Or does the engine have to be warmed up first? Thanks as usual for the replies. -Mike

 

You should be able to turn by hand but not spin easy. Start the car also, and have someone shut it off, and see how much it spins when off, if a lot it is bad.

 

With engine off grab hold of the fan rock the fan back and forth for play. That's how you check for bearing wear. It should be able to turn freely. When you rotate it by hand. If you see oil that looks like its coming from the clutch fan shaft then it needs to be replaced.

 

Yep, oil is a good sign it's time to replace.

 

The max lateral movement at the fan tip is 3/16", according to the the Chassis Manual.

 

My old fan clutch passed the above tests. What is did not do was engage when it should...
When you first start the car cold, the fan should give a distict roar for 5-30 seconds while its internal silicon fluid is dispersed.

Also, when the car is running hot, at idle, it should cycle on and off depending on radiator temperature.
After a long hot drive, park the car and keep it idling. Open the hood and listen for the roar. When you hear it, stand at the left front fender, poke your head under the hood and look at the fan. Your hair will be blowing wildly and it will be loud. As the radiator cools, the fan will start freewheeling (and quiet down) until it gets hot again.

An infrared thermometer can help verifying engine and radiator temperatures. The fan should engage around 195* radiator temps or so.

 

So do you recommend a standard fan clutch or should I go heavy duty
for those Arizona summers?

 

I would put a heavy duty one on it. Just a few more dollars.

 

How about for us guys without hair. I guess I need a wig for the next time. I check a clutch fan.

Sorry Rob I couldn't help myself.

 

If taking your cap off won't work to expose the test hairs, then just turn and face the front of the car, take your shirt off, raise your right arm, and......

 

is it necesasary to use the fan clutch. can you just use a flex lite fan?

 

I tried a couple of those flex fans back in the 70's on some 455 Buicks.
They sure made a lot of noise and the motors didn't seem to run any cooler.

 

Not only that, but they have this bad tendency to come apart at the wrong time (any time for that matter) and do mondo damage to under hood items like the radiator, hoses, that nice $3000 OAI hood.....you know...nothing too crazy.

 

Before I raised my arm to test for the correct wild hair movement would I have to take the dreadlocks and cornrows out first if I were a european women?
Could just wear shorts and stand on the fender?

Real carpenters keep a special hair in their wallet.
When a piece is just a hair big or small you need something to measure how much you have to cut off or add. Also need one to demonstrate at the bar how close you got, or didn't, holding your thumb and index finger slightly apart to show just doesn't have enough visual impact and is hard to see.
All guys specially procured hairs are different so you have to synchronize hairs with the crew before you start work in the morning to avoid discrepancies.
I've never worked with female carpenters?
They sure wouldn't need to carry any of those very special hairs in their wallet?

All the single guys at work with no luck would want to be borrowing one.

 

They also put extra strain on the water pump bearings, causing them to fail sooner.
I would just stick with a clutch fan for street use.

Blue, I am gonna have to keep my comments to myself this time...

 

x2 Flex fans look good hanging on a wall.

 

Flex fans look good hanging on a wall.

Funny but true, I sold one to a buddy and it's been hanging in his garage for 25 years. I guess he's the sentimental type.

 

....Blue, I am gonna have to keep my comments to myself this time...


Yep... me too! LOL!!!

 

Cut the line ... Or leave it ... I worked for a carpenter and he did not want me to ask him anything ...

so I shut up and learned a lot ...