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My old vcu stripped down and cleaned. Need to get around to rebuilding it and testing it.
 
Interesting reading. As pointed out other than compensating for the gearing issue it's the same as bench testing them which is a service currently available.
I suspect that was the reason the Austen came up with using 45° at the hub, instead of the 90° suggested.
Obviously turning the hub through 45° results in the VCU turning almost one complete revolution. This is considerable more than Bell actually turn them on there bench test.
So because the number of degrees of rotation is higher. In accuracy will be proportionately lower and more repeatable.
 
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I suspect that was the reason the Austen came up with using 45° at the hub, instead of the 90° suggested.
Obviously turning the hub through 45° results in the VCU turning almost one complete revolution. This is considerable more than Bell actually turn them on there bench test.
So because the number of degrees of rotation is higher. Accuracy will be proportionately lower and more repeatable.
Yes that makes perfect sense.
 
View attachment 110167
My old vcu stripped down and cleaned. Need to get around to rebuilding it and testing it.
A man with your welding skills should have that done in a couple of hours. Might make sense to put the fluid in first, then each disk separately, otherwise it takes ages to mix it down through and between the disks.
 
Can't you put the discs in one at a time drizzling a bit of fluid between them to get it in a bit quicker.
 
Can't you put the discs in one at a time drizzling a bit of fluid between them to get it in a bit quicker.

Welding up with fluid in it is not exactly going to improve the longevity of the fluid - although I have done it myself.

Next one I shall rebuild it, weld it up, and then vacuum it out with the air-con vacuum pump before I let the fluid suck in. I suspect that is how they are originally filled.
 
I think that's the mystery of them. You can see the ball bearings in the original holes and the new welds. My concern is burning the fluid. I'd be I no hurry so if it takes a long time to fill it doesn't matter.
 
Can't you put the discs in one at a time drizzling a bit of fluid between them to get it in a bit quicker.
I guess you could but this stuff is like working with silicone sealant as in very very messy.
I squirt it in now with a syringe.

Edit, I just remembered one of the guys puts the fluid into a grease gun and uses grease nipples instead of bolts. If you could let the air out as you squirt the fluid in that might be a good way to do it.

https://www.landyzone.co.uk/land-rover/vcu-torque-test-results.109486/page-43#post-3829417
It's messy and slow but works without any risk of harming the fluid.
BTW I just did the OWU test on my VCU and very happy to say it was under 20 seconds. :)
I guess I must have got the correct amount of fluid in after all. ;) Last time I had to let some out to bring the time down to that level as it was around 1 minute.
 
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20 seconds is a respectable time Ali, and bang on what a new GKN unit shows.

I'm using the grease nipple and grease gun filling method for mine, when I actually get round to it.
 
Hi all,
Back in the land of money pit, sorry, Land Rover.
Got a pretty decent 53plate TD4s manual, 122k on the clock.
Not yet done many miles in it (thankfully !)
Removed propshaft and VCU after doing the one wheel test, found at that time that the amount of force needed to actually get the wheel to turn, was frightening, no binding of brakes etc.
Got the VCU off the shafts, drilled two smallish holes diametrically opposite in the end plate to see what comes out.
Looked like something from Quatermass and The Pit, very thick black treacle.
Now in the vice, the unit can only be rotated with LOTS of force and estimate that to turn 5degrees takes 2 minutes with a 17mm spanner on a refitted end bolt (and painful hand).
I recon this is well and truly 'goosed', a second hand complete prop now on its way to me, think I may just have saved the transmission..........going to open up the holes drilled in the VCU, got a variety of 'fittings' to fill the holes when done........hope the replacement has less resistance?????????
 
Allow time for the black goo to ooze out. Then tap the holes to take grease nipples. You can then use an old, or new grease gun to pump in some fresh fluid. Leave one nipple out and pump in fresh through the other. This is the method I'm using when I get round to doing mine.
 
Hi all,
Back in the land of money pit, sorry, Land Rover.
Got a pretty decent 53plate TD4s manual, 122k on the clock.
Not yet done many miles in it (thankfully !)
Removed propshaft and VCU after doing the one wheel test, found at that time that the amount of force needed to actually get the wheel to turn, was frightening, no binding of brakes etc.
Got the VCU off the shafts, drilled two smallish holes diametrically opposite in the end plate to see what comes out.
Looked like something from Quatermass and The Pit, very thick black treacle.
Now in the vice, the unit can only be rotated with LOTS of force and estimate that to turn 5degrees takes 2 minutes with a 17mm spanner on a refitted end bolt (and painful hand).
I recon this is well and truly 'goosed', a second hand complete prop now on its way to me, think I may just have saved the transmission..........going to open up the holes drilled in the VCU, got a variety of 'fittings' to fill the holes when done........hope the replacement has less resistance?????????
Your already on the road to fixing it yourself. Here's how I did it.
https://www.landyzone.co.uk/land-rover/how-to-recondition-a-vcu-yourself.307445/
 
I have a question we have not found the answer, I even sent an email to GKN but did not respond.
In PDF VISCODRIVE i found this.....

Technical Features

> System is sealed for life requiring no
maintenance
> Silicone fluid is optimised with specific
additives for lifetime performance

> Viscous plates have specifically designed
slots/holes and heat treatment
> The degressive locking characteristics (viscous
mode) can be tuned by fluid viscosity, number
and size of plates, and fluid filling percentage
> The “Hump” mode activation is tuned by the
fluid filling percentage
> Steel coupling applications are laser welded

.......So where i find then and what we are ???
 
Your last line was a bit cyptic - but are you asking how we find out what the optimising additives are? That Tony, is the 64 million dollar question! Together with what exactly is the "silicone fluid" and how much is put in! We, and the reconditioners, can only make best guesses! GKN and LR will not divulge the info.
 
In my opinion lifetime performance is longevity........... I don't think you'll see a genuine VCU fail at 20k -30k.......
 

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