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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
Viscous Fan clutch replaceable? Confirmation?
Hey good people. I am 99% certain that the answer is no it is not, but just checking. Is the TD5/TDCI viscous fan centre replaceable (as it was with TDIs), or not?

Cheers... Thumbs Up
Post #1015247 15th Nov 2023 9:13pm
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TexasRover



Member Since: 24 Nov 2022
Location: Paris
Posts: 798

France 2002 Defender 110 Td5 DCPU Chawton White
They look rivited. You probably could but could you buy the core

Possibly a hot climate issue but I found the plastic fan has a life span also
Post #1015282 16th Nov 2023 6:49am
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Mungopark



Member Since: 08 May 2017
Location: Wiltshire
Posts: 15

United Kingdom 2000 Defender 110 Td5 CSW Epsom Green
Out of interest why are you looking to replace ?

My fan seems to engage more often than it used to with no discernible change in the temp gauge (which is pretty inaccurate I know). Is this a sign that the viscous coupling is starting to deteriorate and become more viscous and needs replacing ? I suspect it is the original item and has done 160k miles +.
Post #1015286 16th Nov 2023 8:48am
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excossack



Member Since: 22 Feb 2012
Location: North West
Posts: 5745

United Kingdom 1999 Defender 110 Td5 SW Caledonian Blue
Re: Viscous Fan clutch replaceable? Confirmation?
geobloke wrote:
Hey good people. I am 99% certain that the answer is no it is not, but just checking. Is the TD5/TDCI viscous fan centre replaceable (as it was with TDIs), or not?

Cheers... Thumbs Up


Big spanners! 1999 Defender TD5 110

Regards
John M0VAZ
Econet Station 48 no clock
Post #1015287 16th Nov 2023 9:14am
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
TexasRover wrote:
They look rivited. You probably could but could you buy the core

Possibly a hot climate issue but I found the plastic fan has a life span also


Yeah it is. Just had another look whilst fitting the replacement replacement alternator. Seems a bit wasteful not being able to replace the viscous unit to me.

Hey-ho. It is off now for the winter, so this is an Easter problem. Thumbs Up
Post #1015321 16th Nov 2023 3:14pm
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
Mungopark wrote:
Out of interest why are you looking to replace ?

My fan seems to engage more often than it used to with no discernible change in the temp gauge (which is pretty inaccurate I know). Is this a sign that the viscous coupling is starting to deteriorate and become more viscous and needs replacing ? I suspect it is the original item and has done 160k miles +.


The traditional method of testing the fan is to stick a rolled up newspaper into the fan whilst it is spinning. It is not for the feint of heart and should only be conducted by a professional.

At startup and idle, if done first thing and the paper easily stops then the fan then the viscous clutch is not engaged. If the fan does not easily stop and chews the newspaper up then it is likely the fan is stuck/locked in the engaged position and therefore is not working properly.

If done after a good run when the engine is up to temp (and therefore the viscous clutch should engage) and the fan doesn't stop easily then the fan is working as it should do. If however the fan easily stops when the engine is up to temp then the viscous unit is not working.

In my case the fan is almost solid all of the time, which is weird as it was working just fine a few months ago. Think I will give the viscous unit a few months to "think about what it wants in life"... It is winter after all. Who needs a fan really.
Post #1015325 16th Nov 2023 3:26pm
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
Re: Viscous Fan clutch replaceable? Confirmation?
excossack wrote:
geobloke wrote:
Hey good people. I am 99% certain that the answer is no it is not, but just checking. Is the TD5/TDCI viscous fan centre replaceable (as it was with TDIs), or not?

Cheers... Thumbs Up


Big spanners!


Always have the big spanners on hand Rolling with laughter They live in Miffy.
Post #1015326 16th Nov 2023 3:27pm
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excossack



Member Since: 22 Feb 2012
Location: North West
Posts: 5745

United Kingdom 1999 Defender 110 Td5 SW Caledonian Blue
But skinny spanners to get the viscous fan off. 36mm ? 1999 Defender TD5 110

Regards
John M0VAZ
Econet Station 48 no clock
Post #1015329 16th Nov 2023 3:47pm
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
A pair of spanners on the TD5, one to hold the pulley and one to crack the nut.

Actually they are a superb pair of spanners that have many many uses. I have changed the pulley bearing with them and they work as diff flange spanners too.

Mine are Difflock.com items and are now quite modified Rolling Eyes

https://www.difflock.com/td5-v8-viscous-fan-tool
Post #1015331 16th Nov 2023 3:52pm
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excossack



Member Since: 22 Feb 2012
Location: North West
Posts: 5745

United Kingdom 1999 Defender 110 Td5 SW Caledonian Blue
I got a pair, no idea what make but they appeared on the forum for sale and nabbed them 1999 Defender TD5 110

Regards
John M0VAZ
Econet Station 48 no clock
Post #1015333 16th Nov 2023 3:53pm
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Mungopark



Member Since: 08 May 2017
Location: Wiltshire
Posts: 15

United Kingdom 2000 Defender 110 Td5 CSW Epsom Green
geobloke wrote:
Mungopark wrote:
Out of interest why are you looking to replace ?

My fan seems to engage more often than it used to with no discernible change in the temp gauge (which is pretty inaccurate I know). Is this a sign that the viscous coupling is starting to deteriorate and become more viscous and needs replacing ? I suspect it is the original item and has done 160k miles +.


The traditional method of testing the fan is to stick a rolled up newspaper into the fan whilst it is spinning. It is not for the feint of heart and should only be conducted by a professional.

At startup and idle, if done first thing and the paper easily stops then the fan then the viscous clutch is not engaged. If the fan does not easily stop and chews the newspaper up then it is likely the fan is stuck/locked in the engaged position and therefore is not working properly.

If done after a good run when the engine is up to temp (and therefore the viscous clutch should engage) and the fan doesn't stop easily then the fan is working as it should do. If however the fan easily stops when the engine is up to temp then the viscous unit is not working.

In my case the fan is almost solid all of the time, which is weird as it was working just fine a few months ago. Think I will give the viscous unit a few months to "think about what it wants in life"... It is winter after all. Who needs a fan really.


Thanks Geobloke, I/authorised newspaper tester will give that a go and see what we can figure out.
Post #1015387 17th Nov 2023 8:37am
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blackwolf



Member Since: 03 Nov 2009
Location: South West England
Posts: 16892

United Kingdom 2007 Defender 110 Puma 2.4 DCPU Stornoway Grey
Alternatively with the engine stopped and cold the fan should spin freely, and with the engine stopped and hot it shouldn't.

This approach saves destroying your newspaper and is arguably safer! There again, if you've just bought stuff from Paddocks and it has come packed with 19 identical copies of "The Landy", stuffing them in your fan might be a good way to recycle them! Laughing
Post #1015407 17th Nov 2023 10:45am
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
Rolling with laughter Rolling with laughter Rolling with laughter The farm guys love it when I get Paddocks parcels Rolling with laughter Landys for everyone Rolling with laughter
Post #1015448 17th Nov 2023 5:29pm
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Jabberwocky



Member Since: 27 Oct 2021
Location: Luxembourg
Posts: 195

Luxembourg 
I had overheating issues coming back from Albania earlier this year, there’s an absolve killer of a hill in Croatia just north of Zadar and I had to get recovered off it, turned out to be the viscous fan, did the balled up rag test on it at idle and it failed miserably, fortunately I’d taken a spare so could swap it out. Fan seems fine at idle but as soon as you get to a steep hill it throws in the towel and you have issues.

Apparently you can bodge them with cable ties but I will never do a long trip without a spare viscous fan.
Post #1015493 18th Nov 2023 1:28am
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
Yup I have seen "fixed" viscous fans before where folks have just decided to have them shifting air all the time. the fix is to stick a number of screws into the housing to lock up the clutch. Not great in the longterm but worth knowing if you are in need of a bush fix.

I am fortunate that the clutch seems to be locked on so if I need it I will pull over and throw it on.
Post #1015548 18th Nov 2023 5:08pm
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