Thanks for the information jonaf...I forgot about the tc..I will have to bare that in mind also. ...

These have arrived while ive been away so may have a play today.

subumyza.jpg


I was thinking more on the lines that if the fluid was pressurised what effects it would have on the fluid...As it stands there is atmospheric pressure in a sealed unit...if I add more or even take it away...create a vaccum....I wonder what effects on the fluid it would have?

Maybe with pressure it expands and with a vaccum it contracts or becomes more liquid....supose I will have to try and see if it stiffens up etc..

Are grease nipples air tight to a certain degree?
 
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Just returned to this thread after stay in hospital ( new ankle). To find that two friends both engineers and both hippo owners after reading this thread have been very busy they have use of a commercial workshop and so have taken a different route.

They have split the VCU on a lathe removing the end cap. After dismantling and cleaning they have fine threaded the external body ,Then they have made from scratch a threaded retaining ring that holds it back together.
I understand that there were some problems that they seem to have overcome in notching the end cap to take an O ring + O rings in general Plus they are not happy with the grade of fluid there using and the amount. But they do have 2 test units fitted and on the road all ready.

I do wish they would allow me to post video they have made but as there looking to turn this modification into a commercial enterprise there holding there cards close.

Watch the net for announcments

I have found this discussion extremely interesting. The VCU is a potential problem for all of us.

This may not be a new idea and likely as not someone has contemplated this, but the VCU is about automating power transfer to the rear wheels on an as needed basis. So what about a manually operated mechanism in its place? You forum readers with engineering experience will hopefully critique it. Replace the VCU with some sort of sliding spline arrangement so the driver can select to have 4WD or FWD only. The support is of course already in place. Perhaps electrically controlled and selection made while stopped. It may be a backward step with regards to convenience but it possibly would't need replacing or reconditioning at 70000mls. I suspect that this type of thing may exist on agricultural equipment already. Something like the PTO powering a shaft but a clutch / sliding spline arrangement to a piece of equipment. Likely as not on older equipment!

Is this possible - practical - advisable?
 
There was a guy who made a switchable type spine shaft central diff for the freelander but for the life of me I cant find the forum/thread on it.....I think it was a south african freelander forum, could have been New Zealand thou....there were writeups and pictures looked impressive. .until it broke.....if anyone can find it I would be gratefull...I found it about a year ago but it didn't interest me then so never saved the site..
I was googling freelander stuff and stumbled across it.
 
I blow down this to help expel my old vcu fluid...dont have compressed air:)
u6epuruh.jpg


Got the vcu out in the sun today gently heating it makes it melt
zyjajamu.jpg


I'll have to put factor 15 on to it soon....I wonder if it fancies a bbq?
 
Well its well and truly free now, I can turn it by hand.....now for the fill up job....any recommendations?

Jonnf what do you think? I'm thinking 30,000 too loose. 100,000 too tight....so was thinking 60,000 and vary the amount to get the right lock up I feel happy with....i suspect the vw guys have loose vcus as standard as no report of gear box failure and there always looking for faster lockup. .makes me think landrover have specified too tight a vcu?.......unless the transmission components are really weak? But seem sturdy enough to me?.....did they fook up on the vcu specs?
 
Well one nipple will fit but on the other side is the torsion damper, this wont fit on flush with a nipple installed..so will have to plug it with a bolt instead...why are 2 grease nipples needed anyway? You only need one to fill through and just a hole for air to escape..
 
I have found this discussion extremely interesting. The VCU is a potential problem for all of us.

This may not be a new idea and likely as not someone has contemplated this, but the VCU is about automating power transfer to the rear wheels on an as needed basis. So what about a manually operated mechanism in its place? You forum readers with engineering experience will hopefully critique it. Replace the VCU with some sort of sliding spline arrangement so the driver can select to have 4WD or FWD only. The support is of course already in place. Perhaps electrically controlled and selection made while stopped. It may be a backward step with regards to convenience but it possibly would't need replacing or reconditioning at 70000mls. I suspect that this type of thing may exist on agricultural equipment already. Something like the PTO powering a shaft but a clutch / sliding spline arrangement to a piece of equipment. Likely as not on older equipment!

Is this possible - practical - advisable?

I asked ATL in Hamilton if they could knock something like this up, or alter the IRD to provide an engage/disengage mechanism for the pinion gear - their response was NO!
 
is that half a turkey baster?

what did you do with the other half!!!


Well spotted that man:D The other half I just put aside, it may come in handy for something else:scratching_chin:
 
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There was a guy who made a switchable type spine shaft central diff for the freelander but for the life of me I cant find the forum/thread on it.....I think it was a south african freelander forum, could have been New Zealand thou....there were writeups and pictures looked impressive. .until it broke.....if anyone can find it I would be gratefull...I found it about a year ago but it didn't interest me then so never saved the site..
I was googling freelander stuff and stumbled across it.

I've been trying to find info' on this. Has anyone else had a go? Found any links?
 
Rolling about in my wheelchair has given me plenty of nosey time to talk and watch the chaps and question them on what they want to end up with and why.

There goal is to end up after finishing there modification with a VCU that any person with even a little mechanical ability will be able to service themselves time after time after time.
A point in fact the retaining collar holding it together only needs two simple tools to remove it ( the wheel keys of an angle grinder) and your apart,

Since I last spoke they have bought on board a professional lathe operator who splits a VCU in under 5 min in fact all!! the machine work threading grooving takes less than 50 min in total cleaning out old gel and plates by steam about the same.

They are at the moment playing with various silicons whilst scouring breakers for duff VCUs.
My wifes TD4 Is being fitted with a 450000 filled VCU as a trial lots of sand and loose rock where I live probably going back to 300000 if it does not perform as thought. will report back during week
 
Well its well and truly free now, I can turn it by hand.....now for the fill up job....any recommendations?

Jonnf what do you think? I'm thinking 30,000 too loose. 100,000 too tight....so was thinking 60,000 and vary the amount to get the right lock up I feel happy with....i suspect the vw guys have loose vcus as standard as no report of gear box failure and there always looking for faster lockup. .makes me think landrover have specified too tight a vcu?.......unless the transmission components are really weak? But seem sturdy enough to me?.....did they fook up on the vcu specs?
I have never used anything thicker than 30.000cSt. That is slightly hinner than the original fluid but it puts less stress on the drivetrain.
 
Interesting...did you manage to get all the old fluid out?

When you were about to refill your vcu with new fluid how loose was it? , could you turn it by hand in either direction..Mine now must be empty of old fluid nothing is coming out now and I can now turn it by 1 hand in either direction.

In hindsight, I should have just removed enough old fluid so that I was happy with the resistance...and seen how it went..

This is what came out mixed with turps minus any spillage.
9uty9yre.jpg


udu5a3at.jpg


And this is what I used to get the old fluid out.

ajequhem.jpg


nene9a9y.jpg
 
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Getting the old fluid out takes either time or effort. I chose to empty my VCUs by letting the old fluid seep out. It takes day, even weeks but heating will speed up the process. It is not necessary to drain it completely. When some of the old fluid has been drained it can be replaced by new, thinner fluid.
 
Hmmm...thats my dilemma now...when I partly drained the fluid, the vcu still had quite a bit of resistance, in fact in hindsight I could have just left it partly drained and it still would have operated...but now I have nearly all the old fluid out it turns freely with one hand. ...Im just trying to guesstimate a viscosity to try.

With your vcu partly drained what sort of resistance could be felt when turning the vcu? Could you move it by hand?

As mine is more or less turning with very little resistance im thinking I may need a thicker viscosity as I wont be mixing it with much old stuff...

To be honest if I was really tight, I could put the old stuff back in as the turps seems to have un-gelled it and now seems quite fluid..The turps dont seem to want to evaporate from it....

Did you not use a 100,000cSt in onebof your vcus jonaf? Or was that someone else?


And yes even with the help of turps it's taken about a week too get the fluid out...you cant rush it..it will come out in its own time.;)
 
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Turpentine substitute: is an oil based fluid. Would white spirit work, it has the advantage of evaporating off and only leaving the original contents.
 
Rolling about in my wheelchair has given me plenty of nosey time to talk and watch the chaps and question them on what they want to end up with and why.

There goal is to end up after finishing there modification with a VCU that any person with even a little mechanical ability will be able to service themselves time after time after time.
A point in fact the retaining collar holding it together only needs two simple tools to remove it ( the wheel keys of an angle grinder) and your apart,

Since I last spoke they have bought on board a professional lathe operator who splits a VCU in under 5 min in fact all!! the machine work threading grooving takes less than 50 min in total cleaning out old gel and plates by steam about the same.

They are at the moment playing with various silicons whilst scouring breakers for duff VCUs.
My wifes TD4 Is being fitted with a 450000 filled VCU as a trial lots of sand and loose rock where I live probably going back to 300000 if it does not perform as thought. will report back during week


You mentioned earlier that they were putting a fine thread on the 'end' and the body and using a collar to join them and that the collar had 'O' ring/s

In a previous life I was a cable jointer with the PO here. I came across a brass joint enclosure that was both gas and water tight. There was the lid/cap that slid down over the joint [ loading coils as I recall] and you screwed it to the base. The thread was a fine gas thread, very slightly tapered and there was a single 'O' ring the engaged with a machined lip inside the lid/cap. You undid it with a tool like but larger than and oil filter canister strap.

That design may have applications in your people's project. It could do away with a thread and collar.
 
Hmmm...thats my dilemma now...when I partly drained the fluid, the vcu still had quite a bit of resistance, in fact in hindsight I could have just left it partly drained and it still would have operated...but now I have nearly all the old fluid out it turns freely with one hand. ...Im just trying to guesstimate a viscosity to try.

With your vcu partly drained what sort of resistance could be felt when turning the vcu? Could you move it by hand?

As mine is more or less turning with very little resistance im thinking I may need a thicker viscosity as I wont be mixing it with much old stuff...

To be honest if I was really tight, I could put the old stuff back in as the turps seems to have un-gelled it and now seems quite fluid..The turps dont seem to want to evaporate from it....

Did you not use a 100,000cSt in onebof your vcus jonaf? Or was that someone else?


And yes even with the help of turps it's taken about a week too get the fluid out...you cant rush it..it will come out in its own time.;)

If you keep turning your drained VCU it will lose resistance when the remaining fluid is distributed inside the housing. You need to have a certain minimum of fluid to make it engage.
When the unit is almost full, the resistance will rise. I think 100.000 cSt fluid is way to thick but I have not tried it so I can't tell from experience.
 
Will the use of the solvent like turps or its substitute cause problems with residue. The residue left by such is slimy. I think this would affect the way the fluid grips the plates.
A non residue cleaner would be better. Maybe clean with turps then flush out with brake cleaner.
 

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