DIY VCU service

guineafowl21 said:

I suppose we need an insider at Bell to tell us exactly how they are tested. That would be the standard to aim for.

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erm No. Bells wouldn't tell you, and if they did, they would spin a yarn that suits them.

You'd do better getting 10 or so new GKN ones and testing them.

In fact if someone was interested enough they'd get a new GKN one, open it and have the fluid analysed to see exactly what it is.

Alibro said:

Our seller replied and it is interesting. Here is his reply.

Hi
The minimum I can sell is 400ml and the price is £25. Just buy one of my current listings and state the viscosity required in the check out message. Most freelander owners buy 100,000 from me


As my IRD and Diff could well have been weakened by the tight VCU I wouldn't consider 100,000 but might go for 50,000 or 60,000.

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Found the same site. 60,000 sounds about right to me too.

GrumpyGel said:

erm No. Bells wouldn't tell you, and if they did, they would spin a yarn that suits them.

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That's why we need a snitch on the inside - to break down the last bastion of Freelander DIY!

At the risk of asking a stupid question, Is there any reason not to drill the two holes at the same side of the VCU. This way you could use valves in both holes without the counter balance interfering. I know Jedi said it wasn't worth having nipples but others have said they are useful. At least that would make them an option.

Alibro said:

At the risk of asking a stupid question, Is there any reason not to drill the two holes at the same side of the VCU. This way you could use valves in both holes without the counter balance interfering. I know Jedi said it wasn't worth having nipples but others have said they are useful. At least that would make them an option.

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Good idea. I suppose you wouldn't get such a good flush of fluid that way, but I plan to drain the fluid. fill with brake clean and then rotate to clear the plates.

How about:

1. Drill 10mm holes in the rear of the VCU 180deg apart.
2. Allow fluid to drain, helped by compressed air/brake cleaner/heat.
3. Ensure VCU can be turned by hand.
4. Tap and plug bottom hole.
5. Refill with 60,000 cst siloxane - 140ml. Source here: (request 60,000) Silicone Oil 100,000 100000 Cst 400ml Viscous Coupling Silikonol Freelander | eBay

6. Tap and fit plug or grease nipple to top hole.
7. Test VCU on bench - ensure it turns slowly with breaker bar but resists rapid rotation. Adjust fluid volume as necessary to make it perform like this: https://m.youtube.com/watch?v=0jkvamLKorc

8. With VCU fitted, do 1 wheel up test.

guineafowl21 said:

How about:

1. Drill 10mm holes in the rear of the VCU 180deg apart.
2. Allow fluid to drain, helped by compressed air/brake cleaner/heat.
3. Ensure VCU can be turned by hand.
4. Tap and plug bottom hole.
5. Refill with 60,000 cst siloxane - 140ml. Source here: (request 60,000) Silicone Oil 100,000 100000 Cst 400ml Viscous Coupling Silikonol Freelander | eBay

6. Tap and fit plug or grease nipple to top hole.
7. Test VCU on bench - ensure it turns slowly with breaker bar but resists rapid rotation. Adjust fluid volume as necessary to make it perform like this: https://m.youtube.com/watch?v=0jkvamLKorc

8. With VCU fitted, do 1 wheel up test.

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That all seems straight forward to me. For plugs in the holes I'd use large 'grub' screws [allen key type] - 10mm would be ideal and thread sealing paste to seal. As a cleaner / thinner I'd personally use 100ml of white spirit [or similar]. But before drilling I'd carefully weigh the VCU, drill & add 'thinners', agitate and drain, collecting all that comes out. I'd keep that and allow the white spirit to evaporate off, then carefully measure what's left. That would give a reference point to compare the refill with. Refill again with white spirit... for a final clean, drain, apply air pressure to assist removal of any white spirit, then refill with new silicon to the starting weight? seal and bench test.

Has anyone cut a VCU open to see what the clearances are inside, don't want to drill the plates inside do we?

Two holes drilled 180º apart but how about at either end. On the curved face or on each the flat end plates?

EDITED:

I drilled a hole in the side of my old vcu near the top. Hole was 4mm diameter. It had been exercised by doing 20+ one wheel up tests, to mix the fluid around and also test it before opening.

Edit:
video added

https://www.youtube.com/watch?v=8nDn1rqL_3Y

guineafowl21 said:

How about:

1. Drill 10mm holes in the rear of the VCU 180deg apart.
2. Allow fluid to drain, helped by compressed air/brake cleaner/heat.
3. Ensure VCU can be turned by hand.
4. Tap and plug bottom hole.
5. Refill with 60,000 cst siloxane - 140ml. Source here: (request 60,000) Silicone Oil 100,000 100000 Cst 400ml Viscous Coupling Silikonol Freelander | eBay

6. Tap and fit plug or grease nipple to top hole.
7. Test VCU on bench - ensure it turns slowly with breaker bar but resists rapid rotation. Adjust fluid volume as necessary to make it perform like this: https://m.youtube.com/watch?v=0jkvamLKorc

8. With VCU fitted, do 1 wheel up test.

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That is what I had in mind except I was thinking of filling it with both holes facing up to allow air to escape from the 2nd hole. From what others have said the stuff is pretty gloopy,

have a read of this....

The Mad Hat Man said:

have a read of this....

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Flicked through it quickly but didn't see anything about DIY repairs. Did I miss it?

Edit, read first half again and got bored. Load of nonsense about putting an electro magnet on the outside of a steel unit and expecting the magnetism to magic itself into the fluid inside. Ever tried to get magnetism through steel. Don't work.

Alibro said:

Flicked through it quickly but didn't see anything about DIY repairs. Did I miss it?

Edit, read first half again and got bored. Load of nonsense about putting an electro magnet on the outside of a steel unit and expecting the magnetism to magic itself into the fluid inside. Ever tried to get magnetism through steel. Don't work.

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I think the idea is to use a magnetic field. In this case a strong localised one, and yes it does work. Isn't this principle used in isolating transformers?

Alibro said:

Ever tried to get magnetism through steel. Don't work.

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Eh???!!! Magnetic flux travels well through iron, the major component of steel. If that weren't true, transformers wouldn't work, for a start.

Is NI in a different universe with different physical laws?

Alibro said:

Flicked through it quickly but didn't see anything about DIY repairs. Did I miss it?

Edit, read first half again and got bored. Load of nonsense about putting an electro magnet on the outside of a steel unit and expecting the magnetism to magic itself into the fluid inside. Ever tried to get magnetism through steel. Don't work.

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The idea came from LR Evoque suspension dampers. They're magnetically controlled. The damper liquid has metal bits in it. Varying the applied magnetic field varies the stiffness.

guineafowl21 said:

Eh???!!! Magnetic flux travels well through iron, the major component of steel. If that weren't true, transformers wouldn't work, for a start.

Is NI in a different universe with different physical laws?

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LOL, I could be wrong (often am) but I used some very powerful magnets to build a wind turbine a few years ago, with the magnets stuck to two brake disks facing each other. On the magnet side lots of magnetism, drop a spanner in there and you have a big job getting it out, on the other side none at all.
Maybe different with electro magnets.

However back in the real world I've just ordered the parts I'll need to drill and tap my VCU for 60,000cst oil.

I thought the idea was to cut the weld, strip it, clean it, put fluid in and weld end back on.

Good luck. Because I am still not convinced that this is not just a "guess it and hope" scenario.

The fluid has never been verified.
What proof is there that white spirit is a thinning compound for a silicone based fluid?
The fluid to air gap is supposed to be critical.
Hence the fluid volume is also critical.
Just because it "works" doesn't mean it works "correctly".
Luckily it isn't a safety critical component. If it works at all the worst it can do is destroy your transmission or give you no drive.

Personally I wouldn't risk the IRD and diff for a couple of hundred pounds. I would be checking the VCU on a very regular basis and noting the results.

But then what do I know?

I used to recon alfa ones. They were stripable and supplied you with fluid etc to do the job.

I've driven two recently with recon vcu's both very different mine tight. The other very loose?
Mine might have custard in it!

Don't get me wrong - we need peeps to experiment - but at this stage it is still that.