testing a viscous coupling

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BMGTZ

Grumpy old man from the school of hard knocks
Joined
Mar 9, 2007
Messages
4,555
Location
southside of perth WA
As the title asks....I need the method used to test a viscous.

I have spent hous searching today but havent found any manuals that say how.

I saw something about a lathe and 100 rpm...but it was iffy at best
 
Send them over to Mike Dale Automotive (Blackvr) here in Adelaide, Mike has made up all the special tools required to accuratly test their pre-load.
 
Send them over to Mike Dale Automotive (Blackvr) here in Adelaide, Mike has made up all the special tools required to accuratly test their pre-load.


since I have about twenty to test.....I would like to do the same. as in make the tools and do the tests. I also want to be able to set up my adelia
 
i dont reckon you can do much other than test that they arent locked up and that they have some locking capacity. because they apparently have different characteristics when they get warm. as i sure you know from those charts on the same page as that strange lathe test.
i reckon that you shouldnt be able to slip it when its hot. i liked the testing here:
http://www.youtube.com/watch?v=zMqOebMnZKo
i sure you would have seen this about vw viscous:
http://www.syncro.org/VCTest.html
it says that if you jack rear wheels up, at idle the car shouldnt move, but any higher than idle the car should drive forward.
also is a chart showing that coupling needs to be above 100c to work properly.
that page look like the goods to me
 
yeah i saw that video Jack.... he looks like he is trying hard to stuff that car :rolleyes:

there must be a procedure some where to test these....
 
I saw a couple of pages that mentioned a lathe ....but nothing that had any tables/ charts on it ....link?

"as i sure you know from those charts on the same page as that strange lathe test"
 
Send them over to Mike Dale Automotive (Blackvr) here in Adelaide, Mike has made up all the special tools required to accuratly test their pre-load.

I have sorted out my own " calibration test " , but its probably not as quantitative as you are chasing Brian. I set them up in my vice via an machined down centre diff ... and use a torque wrench
to calculate how much pre load it takes at my "calibrated" rotation to brake away the plates. A bit rough, but it appears to work in real life ! I have a selection of viscous couplings of different pre load settings
for different applications. ie tarmac, gravel rally and general road cars. They do vary a bit in pre loads, and you can feel the difference in competition gravel/tarmac cars. There is no doubt the Ralliart units have stronger
pre load, but not that much more than some stock units I've tested.

Works for me, and I'm not sure that it needs to be tooo over complicated.

Mike
 
http://www.syncro.org/VCTest.html

there is another link at the bottom the page that has some other general info about vc. the interesting part is about changing the fluid in the units, this means fluid is available, maybe we can drill a hole and tap for a drain plug so as to be able to change fluids for some thicker stuff.

i think your adelia needs to be set up as tight as you can without it causing bad noises when parking. maybe measure one of the cone type lsd and start at that figure.
 
Brian

Create a tool out of a spare VC spline so that you can mount it onto a torque wrench and test preload.

Preload should be 47-55Nm


http://www.4gtuner.com/topic/11828-viscous-coupling-testing/page__p__150452__hl__%2Bviscous+%2Bcoupling+%2Btorque__fromsearch__1#entry150452



PS I have a home made tool if you need, as I've done this before.
-alex
 

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