Viscous coupling and where from ?

[tonyc280]

Hi chappies. I think my viscous coupling has had it. Just wondering how hard to get off and where to get one from. Cheers, tony. Car is a c280 w202

 

[stwat]

I bought one from wunderpartz a few years ago and it's still working fine. As you would expect.

Mercedes Viscous Fan Coupling C E CLK SL G 240 280 320 430 55 AMG 1122000122 | eBay

 

[tonyc280]

Ok cheers have emailed them but how difficult is it to remove old one please. Cheers

 

[stwat]

I used the online startek manual to do mine on the S. But there is lots of info in google land. https://www.google.co.uk/webhp?sour...,d.d2k&fp=2da79b5fde7ad2ac&ion=1&pf=p&pdl=300

 

[tonyc280]

looked at the guide but very heath robinson i have to say. using a brick for a hammer and look at the mess his garage is in. Only thing i learnt from threads is that its a 36mm spanner and it has an opposite thread. Thanks.

 

[stwat]

I certainly wouldn't recommend that youtube method

There are lots of links with how to's on the google page. Not all for the same model but it;s basically the same job on any merc visco coupling.

 

[johnsco]

I changed one on the E430 very-recently.
Easily-available and VERY-reasonably-priced from Wunderpartz.
They supplied a genuine German spare - guaranteed for 2 years - and it's still working with no problems.

I'm not sure that all of them are a left-hand thread.
If you get a replacement and check out the thread on that - Then that will tell you which way to unscrew.
I recall it was a 36mm slim spanner and there is a special holding tool to stop the part rotating while you unscrew it.

 

[kth286]

Hi chappies. I think my viscous coupling has had it. Just wondering how hard to get off and where to get one from. Cheers, tony. Car is a c280 w202

I think we need to know more about why you think it has 'gone'.

Statement seems too vague to be going to all that expense and bother, for just a hunch.

What's the problem exactly ?

If the pump, thermostat and coolant and rad are all good and genuine, the fan will hardly ever need to start, even in traffic.

I can leave mine idling in the sunshine all day and it will not come on - just stays at full working temp.

 

[johnsco]

I can leave mine idling in the sunshine all day and it will not come on - just stays at full working temp.

I'm not sure that you are talking about the same thing as the OP.
This is not an electric fan with a thermal switch or controller.
It's a belt-driven fan, but with a viscous (fluid) coupling between the driven hub and the fan itself.
The viscous coupling is running (and wearing out) all the time the engine is running.
The viscous coupling contains a thermal sensor that varies the amount of drive that the coupling transfers to the fan.

 

[johnsco]

TYPICAL VISCOUS COUPLING FOR FAN

 

[pingping]

halfords have the removal spanner at 13 quid ,i removed mine couple days ago on my c180 w202 ,just jam a long screwdriver in between the four small bolts to stop fan from turning while using the spanner,quite easy to do,remember threads are opposite to the norm

 

[tonyc280]

Yes it is the one driven by belts. i have two other electric fans as well. The viscous fan wobbles a lot and spins very easily by hand so know it's gone. Cheers.

 

[kth286]

Yes it is the one driven by belts. i have two other electric fans as well. The viscous fan wobbles a lot and spins very easily by hand so know it's gone. Cheers.

Do mean you can spin it by hand when the engine is off ?

If so, viscous fans are meant to do that.

When you can turn it by hand, but you then start engine, the fan will turn, but only because of drag, its not operational in that state.

The wobble is likely to be the bearing of the pulley that the fan is bolted to, not the fan itself.

 

[pingping]

Do mean you can spin it by hand when the engine is off ?

If so, viscous fans are meant to do that.

When you can turn it by hand, but you then start engine, the fan will turn, but only because of drag, its not operational in that state.

The wobble is likely to be the bearing of the pulley that the fan is bolted to, not the fan itself.

i assumed it depended on the type of viscous fan he has on his motor ,thermal or non thermal
this explains it a bit better http://www.offroaders.com/tech/fan-clutch.htm

 

[johnsco]

I changed my viscous coupling because it was wobbling like hell and was occasionally seizing, which caused the fan to race.
It was definitely my viscous coupling that was worn out and not the pulley bearing.
The viscous coupling is the most likely culprit ... If there is actually a problem.

 

[tonyc280]

Blimey chaps talk about making something difficult for an old man like me, Ha. Well have new one now and will be fitting it soon. Thanks for your posts.