TDV8 4.4l - as per other posts things are being taken out to fix a squeaky aux belt.

The question this time is simply, should the viscous fan freely spin when removed from the car? It, along with the cowling, are out of the car. The fan is smooth when turned, however it is stiff to rotate.

If disconnected, should it freely spin? Or is stiff normal? Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

I’ve had a look over YouTube but cannot find something that shows the fan spinning… or not. The closest i have gotten to is for a LR3 far replacement. Both the old and new seem to freely spin, and the design looks very similar to what i have.

I am leaning towards stiff is not good.

The new fan is at 9:50 into the video… (plus however long these bloody adverts are on for now)
 Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

This morning whilst working on the car again, i took another look at the removed viscous fan.
Sure enough, it is stiff like yesterday. In a moment of pondering I kept spinning it… and noticed it was getting easier to spin!

More and more turns later it seemed to loosen, stiffen, and loosen again until it was free wheeling as i would expect them to with barely any resistance.

I left it along for a bit, tried again later and it was stiff again. I repeated this and can say that if you leave the fan alone it stiffens up but loosens when you keep moving it.

I still dont think this is normal. Unless someone says differently I’ll be ordering a replacement fan, hopefully with a decent returns policy. Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

It shouldn't 'freewheel' - after all it has a viscous coupling so there will be some drag by design, where it is different is there is a PWM clutch involved to control the %age of lockup over that of the pure viscous coupling. The fan should rotate smoothly at any given temperature, with equal resistance, of course, the amount of resistance varies with temperature.

Why do you think there is a problem with it?

Good morning Phoenix.

The fan was removed while gaining access to the belt and pulleys, and when I removed it I noticed it was difficult to spin. Given the hassle with getting the fan out I would only put it back if sure it was ok.

As per my last post it is difficult to spin at first but eases up. It goes from turning just a few degrees at first and when I’ve managed to turn it a dozen times and it’s eased it’ll then begin to spin.
Maybe freewheel isn’t the best description as yes there is still resistance… Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

I must admit, it's not a test I've ever done, it does sound like the sort of behaviour I'd expect though. Do you have diagnostics capable of reading the fan speed and commanding it's lockup percentage? That would be the only way to reliably confirm correct operation that I know of.

I remember going to the motor show with my brother in approx 1990 when the viscous transfer box was introduced to the Classic Range Rover. ( Not sure if the viscous fan came in at the same time, but it was included)

We stood watching a demonstration given by someone from the Lode Lane development department.

He had all sorts of bits in his demo including diffs and fans, but the most effective way he could describe how they work has stuck in my mind.

He had a large Pyrex mixing bowl full of hot water and a big wooden spoon.
No matter how hard he stired the bowl remained still.
He then added two heaped spoonfuls of baking powder to the water.
As soon as he started stirring the bowl started to turn.
The faster he stirred the more it spun and he finished by saying that’s how they work

Mike. G reg 2.5VM Vogue Portofino red 1991- 1999
V reg 2.5td P38 Rioja red 1999- 2006
53 reg td6 Vogue Oslo blue 2006- 2015
11 reg 4.4 TdV8 Vogue SE. Baltic blue 2015- date.
https://www.fullfatrr.com/forum/topic56162...tty+affair

A 'non-Newtonian fluid' - probably corn starch not baking powder though.

Ffrr-lover wrote:

If disconnected, should it freely spin? Or is stiff normal?

Phoenix wrote:

I must admit, it's not a test I've ever done, it does sound like the sort of behaviour I'd expect though. Do you have diagnostics capable of reading the fan speed and commanding it's lockup percentage? That would be the only way to reliably confirm correct operation that I know of.

fisha wrote:

with a smooth fiction feeling.

No, it’s true, not fictional.  Ron B. VK2OTC
2003 L322 V8 Auto
2007 Yamaha XJR1300
Previous: 1983, 1986 RRC; 1995, 1996 P38A; 1995 Disco1; 1984 V8 County 110; Series IIA

I was just making it up … V8 or else ...

Isn't this the part that does the clicky clicky noise (mine does it - more so in winter) but when owners have changed them they start clicky as per usual a few weeks later?
Some simply say leave em...