Tight VC demonstration.

[syncrosimon]

There is this short video, and I believe that some German remanufactured VC's provide a tourque graph of how the Vc performs.

http://www.youtube.com/watch?v=KUatvj937c8" onclick="window.open(this.href);return false;

How that would translate into a vice test i dont know. We need someone with a new one to do some pre tests, then a video like mine to show how it performs. My VC wants to drive the front wheels all the time, gets more aggressive as it warms up.

Then this beemer seems quite tight

http://www.youtube.com/watch?v=4cbGeSJ9 ... re=related" onclick="window.open(this.href);return false;

So... I dont know..

[Syncro G]

If you lift one front wheel you can very very slowly force it round so I guess you could turn it with a torque wrench on the centre nut for a relatively easy to do test (especally if you had the bendy style wrench)? See what load is needed to get it moving (it'll be no where near what should be needed to undo the nut so that shouldn't be an issue)? Not sure if that figure would mean alot though as though it'd show inital slip that might not be directly related to final lockup, especally with age?

[HarryMann]

Not sure if that figure would mean alot though as though it'd show inital slip that might not be directly related to final lockup, especally with age?

Correct Glen, it wouldn't mean much.. it would be about 50 N-m static at a guess and mainly be the VC seal's static friction. A very low figure might indicate the seal's have gone, but that's probably about it.

The std calibration test done on VCs after refilling or during production, as shown on the Syncronauts website here:



is what it says, a calibration check test and is very misleading as to how a VC actually performs in practice. Repeat, this is a calibration test to ensure in-spec and not intended to indicate what happens when driving, it's simply a temp(time) Vs torque test curve at a given (fixed) differential rpm (about 80) on a lathe type drive.

Notice that contrary to what you might read (even in erudite places), silicone fluid's viscosity drops with temperature just like any other Newtonian fluid, indicated by the -ve gradient from static down to the point at which the pressure rapidly rises and the the auto-locking starts (133C in this case being max stable temp)

Here is a bad one: