Testing VCU Units

[Ausfree]

I have been a bit concerned about the reputation of VCU units seizing up in FL1's and have had a good look around at the various tests that can be conducted including the "Tippex Test" which I have conducted on my vehicle, it passed by the way. I thought this information that I saw on another site might be of use to fellow FL1 owners.:D
Symptoms - Bell Engineering (http://www.bellengineering.co.uk/5.html)

[kahuna]

Symptoms - Bell Engineering (http://www.bellengineering.co.uk/5.html)

Thanks! Very good find.
"It has been reported on some internet sites that to test the VCU if you jack the one back wheel of your Freelander without the handbrake applied you should be able to turn the rear wheel and that if you cannot turn the wheel your VCU has seized -THIS IS TOTAL RUBBISH! "

This is not rubbish, but it lacks measurements. I'd like to see: Use 2ft bar on wheel nut, apply 10kg weight, count how many seconds it takes for bar end to move 20cm...

Let's do this all FL1 owners?

PS: my rear diff is dying I guess...

[kahuna]

OK, I'll be the first to measure :))

Have a look at the setup and results here: YouTube- Freelander Viscous coupling testing

Can weights 5kg, pipe 1.25m 2.5kg. I calculated torque is ~80Hm.

Wheel spins at ~ 1deg/sec. Common guys, do it ! :))

[kahuna]

Club 80-90 Syncronauts: Viscous Couplings (http://www.syncronauts.org.uk/?page_id=971)
Yahoo! Groups (http://autos.groups.yahoo.com/group/Syncro/message/5133)
Testing is accomplished by keeping the housing stationery and having the
hub rotate with a constant speed of 75 rpm. Temperature is being measured
by means of a thermo coupling on the outside of the housing. Torque
transfer in Nm vs. temperature (C) at a speed difference of 75 rpm is the
key measurement. The torque level slowly *drops*! as the temperature goes
from 10 degrees C to 120 degrees centegrade (from 250Nm to 140Nm) and then
shoots up to an infinite torque sharply at a point between a temperature of
120 and 135 degrees C.

Viscous Coupling Refurb graphs (http://www.club80-90syncro.co.uk/Syncro_website/TechnicalPages/VC%20Refurb%20Torque%20Curves.htm)
http://www.club80-90syncro.co.uk/Syncro_website/images/Decoupler_CHS_2CR86.JPG

So our wheel test measures only lowest temp torque. And not at 75rpm...

[woko]

Ive started testing them the same way a RRC vicious coupling is tested. It gives you a specified torque to use and how much movement in a specified time.