Disassembling viscous fan

[DaveD]

Theres two opposing theories and the definitive one has never been agreed upon..... mine is locked with silicone and it works at the moment (shrug)

[MattF]

O.K. here's what I done......removed fan assembly, dismantled the viscous coupling, dicarded the front and middle sections, removed the fan and flippped it over, the using the existing threaded holes bolted the fan back onto the rear half of the viscous part using m8 allen bolts and put a dab of gripfil on the ends of the threads so the bolts won't work loose.




Sorry, I forgot this is the Mk2 version of my fan locking

Did you redo it because there was a problem with the original method?
John's really managed to put the sh*ts up me with that info yesterday.
I've done mine with the housing reassembled, but I removed the spring
and friction plate from the front housing, and have drilled two holes
through the rear friction plate and housing and bolted through with brass
8mm bolts, (figured if there was a problem it's better for the locking bolts
to shear, allowing the housing to be spinning, minus friction, independently
of the mount), and then refitted the front housing. Just put it back on now.
I'm going to put the bit of coolant back in that I removed so I could take the
top hose off, and then give it a whirl.

[MattF]

Theres two opposing theories and the definitive one has never been agreed upon..... mine is locked with silicone and it works at the moment (shrug)

It appears as if this subject is a bit like the veg oil debacle. Only way
to find out for definite is to suck it and see. (No, I don't mean it that
way, before anyone suggests. )

[BUSHWHACKER]

Did you redo it because there was a problem with the original method?
John's really managed to put the sh*ts up me with that info yesterday.
I've done mine with the housing reassembled, but I removed the spring
and friction plate from the front housing, and have drilled two holes
through the rear friction plate and housing and bolted through with brass
8mm bolts, (figured if there was a problem it's better for the locking bolts
to shear, allowing the housing to be spinning, minus friction, independently
of the mount), and then refitted the front housing. Just put it back on now.
I'm going to put the bit of coolant back in that I removed so I could take the
top hose off, and then give it a whirl.

I re-done mine when I looked at it thinking there must be a way of fitting just the fan blades to the pulley and not the whole assembly, (save a bit of weight too!) so I took it off, pulled it apart and the way it is now was the best way with using the least amount of parts.

[MattF]

I re-done mine when I looked at it thinking there must be a way of fitting just the fan blades to the pulley and not the whole assembly, (save a bit of weight too!) so I took it off, pulled it apart and the way it is now was the best way with using the least amount of parts.

Oh good. I'm becoming paranoid about this fan now. How long had
you been running it previously, with the three bolt mod? Just fired
mine up, and kept a quick eye on it. Nothing flew off. Must admit,
not as noisy as I was expecting. The way it's been described by some,
I was expecting the fan to be making a right racket when I fired her up.
My bright blue fan assembly is still intact.

[BUSHWHACKER]

Tha'll be the paint holding it together!!!!

My original fan lock-up was on the truck for about six months with the three bolts.
You'll notice the roar of the fan as you accelerate, if you don't then it's probably fallen off!

[MattF]

Tha'll be the paint holding it together!!!!

My original fan lock-up was on the truck for about six months with the three bolts.
You'll notice the roar of the fan as you accelerate, if you don't then it's probably fallen off!

I tried resisting. Honestly. But the housing magically appeared in
the passenger seat of the van as I was passing the blast shop. How
could I ignore an omen like that.

If you went six months on that previous setup, I think it's safe for me
to stop worrying then. If slight misbalances caused a major problem,
it would've shown up within that time frame, I suppose. My panic level
is subsiding somewhat.

[BUSHWHACKER]

So your hands should be steady enough to post some pics on here then!

[MattF]

So your hands should be steady enough to post some pics on here then!

It'll have to be an in engine shot. You chaps without aircon can
get to bolts easier than I. Out of interest, does anyone else
get weird looks from their neighbours when they see camera
flashes coming from your vehicle? Do you want a pic of my
flourescent shocks, (partially waxoyled now), as well???

Oh god, I've just realised who I'm becoming like with all this needless
bling.

[MattF]

Here they are.

[BUSHWHACKER]

[mud skipper]

sorry guys just got in from mine kenlowe is now on and wiried, tomoz moring oil cooler going on, not fired her up ( 2 pizzed at the mo ) mattf my fan self destroyed itselfe on its first outing

[MattF]

sorry guys just got in from mine kenlowe is now on and wiried, tomoz moring oil cooler going on, not fired her up ( 2 pizzed at the mo )

You'll have to post some pics when it's up and running. Be nice to
have a peek at an electric setup. What's it like for fitting?

mattf my fan self destroyed itselfe on its first outing

Anybody ever mentioned that your method of making people
feel better don't work? I'd just stopped worrying till you said
that.

[TonyN]

I can see your logic but in theory (apparantly) the fan is in the line of the airflow which at speed is cooler than the engine therefore the fan (viscous) is actually cool and does not operate at full speed as the coupling is slipping supposedly it locks at low speeds when the fan itself is not being cooled by the airstream

There is bi-metalic spring on the front of the hub that adjusts how hard it drives, fan speed depends on the spring sensing the temp of the rad, diesels run hotter the faster you go, so you will find giving it some stick at high speed the fan helps pull air through the rad if air speed alone can't keep up with the rad.

Deisels normally idle very cool, it takes 20 mins of so with the bonnet up to get the stat open, so the fan doesn't need to drive that hard. 1/2 a mile down the road has most Surfs up to temp and needing air sucked through the rad.

Flexy fans flatten the blades at speed for less drag, and pull harder at lower revs when they are a more aggressive shape, but these work better on petrol motors.

[MattF]

The fan lock *is* a step in the right direction then.
I'm gonna' have to stop doing any mods on the beast.
I worry like this every time I change something.
I'll be grey haired by forty at this rate. Cheers for the
technical clarification, Tony.