Fan blade separating from viscous coupling

But if Gaz only re used what came off in the first place , I would do the same to be honest. You can't realistically check every component to make sure all fittings are present and correct. I trust to experience, that's all.

Tony.
 
But there were no washers on it previously, and that was an OEM fan blade and most likely the original. I'm not arguing for arguing sake, just wondering how the hell I'm supposed to figure out it needs washers if I'm not supplied any or diagrams don't show them :mad:

I got washers, got loads of the bloody things in my toolbox...
 
GazHyde said:
But there were no washers on it previously, and that was an OEM fan blade and most likely the original. I'm not arguing for arguing sake, just wondering how the hell I'm supposed to figure out it needs washers if I'm not supplied any or diagrams don't show them :mad:
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Agreed Gaz, the trouble is someone, at some time or other seems to have replaced the original bolts, possibly because it's easier to do up an allan screw than put a socket on a nut in confined places. Any way the damage is done, the point i would make is try not to make the same mistake as it has quite possibly caused premature failure of the fan.

Mike
 
Yes Mike is right, it was either a hex flange or a sems bolt originally. Using a cap screw means you put more torque into the joint because the under head surface area is less, hence why it has compressed and then split the surrounding material. If it was mine I would use either the correct bolt or a cap screw with washer and the recommended torque or only nip it up, but I would use. A loctite solution to prevent unwinding.
 
I've zoomed in a little bit Mike, and you can see that bolt 3 is the same type as what I've used. The hex headed bolt is for the pulley on the front of the water pump.

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Part no. 3 is what secures the fan to the viscous hub I think.

Tony.
 
Right, done the research, it should be an internal torx cap screw, original cars 1995 had washers, later cars did not. The tightening torque should be 10Nm so not very much, this is just the flick of a wrist. I have torque wrenches if you need them Gaz?
 
I'll see if I can find a car with a similar setup and have a close look tomorrow Gaz and report back. However i still maintain that this would not have happened if a washer had been used on each screw.

Mike
 
EnthuZiaZT said:
I'll see if I can find a car with a similar setup and have a close look tomorrow Gaz and report back. However i still maintain that this would not have happened if a washer had been used on each screw.
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I'm not arguing that they shouldn't be there, just that I can't find evidence either way. I will use the washers I've trimmed down to fit in the available space when I refit - I see no reason not to!

I really do appreciate yours, Tony's and Rich's input on the issue. Hopefully it will inform others should they hit the same silly problem :thumbsup:
 
No I would leave the washers off, I reckon they removed them as a cost saving and lowered the torque, for piece of mind just put some loctite on, but make sure you only use the 10Nm.
 
I've just been looking around the internet at viscous fan couplings, the only one I could find with a clear picture of the fan blade bolted to the coupling was from a Mercedes but don't let that bother us. I stand corrected there is no washer shown under the allan screw on that one either. So I can only conclude it is, as Zedonist has said the screw had been overtightened. Having said that without that knowledge I would most certainly add a washer, just for piece of mind. But then I always over engineer things, so I'm told.

Mike
 
Mike, I agree, especially with a cap screw, if you look on real oem at the early 1995 cars, they did in fact have a washer. But it is really easy to over tighten these, and the substrate just cracks. The way they have all cracked I the same way demonstrates the over tightening. This is the reason the dealer wanted to go through a warranty claim, the investigation would have confirmed this and no claim would be paid, we review them daily, so fair play to Gaz for pushing for and getting a new part.
 
zedonist said:
Mike, I agree, especially with a cap screw, if you look on real oem at the early 1995 cars, they did in fact have a washer. But it is really easy to over tighten these, and the substrate just cracks. The way they have all cracked I the same way demonstrates the over tightening. This is the reason the dealer wanted to go through a warranty claim, the investigation would have confirmed this and no claim would be paid, we review them daily, so fair play to Gaz for pushing for and getting a new part.
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Moral of the story Gaz, you don't know your own strength mate !;)
Joking apart, more fixings fail due to over tightening than under tightening.Fact.

Tony.
 
So using the combined intellect & experience of myself, Zedonist, t-tony, Enthuziast & Lee this is how the new fan blade has been attached to the viscous coupling. I've added the washers and tightened the bolts with a mere flick of the wrist!

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Did you use any loctite on the threads Gaz?

Tony.
 
You used a rusty washer Gaz! this is just not on. Joking aside looks like a proper job, make sure you loctite them down as per Tony's advice.

Mike
 
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