How long do these clutches generally last. Just ordered one from Fastline. I could hold my fan blades with my hand while engine was running and even spin them backwards. Also the fan did not increase in speed as the engine revs went up with the engine hot. Is that how you check it??

The v/8's will usually come in and out audibly with the engine at 1500 rpm or so. The 6's are harder to hear.

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Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

Old before you replace it. Make sure the radiator is getting hot all around the fins if the middle of radiator is cool the fan wont kick on. Its trigger by a bimetalic spring sensor that measures the temp of the radiator.Theres a kinda liquid paste that heats up and makes the clutch engage. Its normal when the engine is cold you can hold the fan blades. That fan clutch kicks in about 95 C.
The electrical fans kick on about 110. Just make sure before you go spend a few hundred dollars/to double check that thermal effeciency of the radiator.





Guido
Factory Cert Tech MB

PLease, never try to stop those fans with your bare hands. You never know when they might decide to give it one more whirl. If the clutch is working, you will be able to hear it come in as Donnie stated, If you have enough heat in front of the clutch, it will come in and if you hold the RPM's at 1500-2000, it will gradually back out again. If the heat is right and you are not heawring this, then the clutch is not working. Save those fingers for scratching your head wondering what will let go next

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Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.

I used to know a Jeff Lawrence. Where are you from?

Jeff,

Since cooling fans in the past few decades have integrated viscous couplings, the fan blade has become much less dangerous. The old direct drive fans were quite dangerous, but if you grab a clutch fan blade (On the side thats on down stroke) you can stop the blade, and the clutch will continue slipping until you let go. I've seen it done, and have done it myself... needless to say that I am still able to type. As always, be cautious anyways.

Jason M.

The viscous fan can be tested by taking a peice of newspaper putting it up against the radiator and seeing if the fan holds it.If it does not you need a new part.Michael.Mos&B scv.ffv.

Jason, what you say may be true, however, I for one, will never try to stop a rotating object with sharp edges that can absorb up to 20 horsepower when fully clutched. I want to hit the dirt at the end of the road with all of my digits. BTW, I have seen viscous clutches that have seized, so I don't trust em with my digital computers.

DEEZEL where are you????

Oldsouth. I am originally from Brooklyn NY, but have lived in the New Bedford MA area for most of my life.

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Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.