jonaf

Active Member

• Nov 22, 2009

• #1

Hi, I am new to this forum. I live in Norway where winter has now arrived and 4wd is needed. I currently drive without the propshafts and vcu because I think the coupling is about to seize.

What is the correct torque it should take to turn the viscous coupling? Mine moves when i apply 120 Nm to one shaft end with the other fixed in a vice.
Before I removed the propshafts the car was binding in corners and the fuel consumption rather high. Now the consupmption has improved and the car is more comfortable to drive.

I have seached several discussion forums and also asked many LR dealers without success.

 

howardo

New Member

• Nov 22, 2009

• #2

try this thread.
http://www.landyzone.co.uk/lz/f9/vcu-torqe-test-78219-4.html

 

howardo

New Member

• Nov 22, 2009

• #3

and this thread.

http://www.landyzone.co.uk/lz/f9/vcu-77917-6.html

 

jonaf

Active Member

• Nov 22, 2009

• #4

Thank your for the links. I became no wiser though. I have carried out all the tests described but I still do not know at what torque the VCU is supposed to move when it is up to official specs.
So far all I know is that my coupling has not completely seized but I do not feel like putting it back because it think it is not going to work properly.
Any tips about firms that may give me a clue? There are none in Scandinavia but in the country of the car's origin there ought to be sources to official information

 

Last edited: Nov 22, 2009

E

eightinavee

Well-Known Member

• Nov 22, 2009

• #5

I asked LR dealer technical support this question,the answer was that LR never released or held the data.So unless you can get it from GKN there is no definative answer.

 

jonaf

Active Member

• Nov 22, 2009

• #6

eightinavee said:

I asked LR dealer technical support this question,the answer was that LR never released or held the data.So unless you can get it from GKN there is no definative answer.

Click to expand...

The only way to find the correct figure will probably be to buy a new unit and measure it then.
A long shot maybe, but I wonder if anybody has done that and can share the information.

 

Chaser

New Member

• Nov 22, 2009

• #7

For comparison, when I tested my VC directly it would slip with 20lbs/ft or 27nm applied so you reading seems very high.

See post 14 of this thread.....
http://www.landyzone.co.uk/lz/f9/vcu-torque-test-78219-2.html

 

howardo

New Member

• Nov 22, 2009

• #8

see post 2 of this thread.
All info needed was in the 2 links.

 

Missing Link

New Member

• Nov 23, 2009

• #9

The second suggested thread give a clue as to the problem of set figures in that it gives a torque against a set RPM. It however does not specify at what temperature because as the temperature of the fluid rises the resistance offered rises. As far as I can find out LR gave GKN the specifications of how it wanted the VCU to perform and they provided the product to match the spec. As such LR do not seem to have any specific test procedure to certify a good VCU, I posted a link a little while ago to a site giving a few pointers based on another manufacturer using viscous couplings (VW) and they release no test figures either ( TheViscous Coupling: How to Test & Replace it ). If you have access to a rolling brake test rig you could try the suggested test except remember the example vehicle in this case has a primary rear wheel drive. As I said previously don't try thr bodge test, it is potentially lethal!