VCU Torque test results

MollyNomad said:

The viscous coupling is a sealed unit and contains several fibrous 'plates' in a silicone based fluid. If it's on it's way out the best policy is to replace it immediately. The VCU will destroy the rear diff, the IRD and potentially the gearbox. There is a thread on here by someone who drained the fluid( took three months ) and serviced the VCU (can't remember how) rebuilt and then refilled with fluid he found on eBay.....

The VCU is the achilles heel of the system and as it 'connects' the front and rear of the vehicle can do serious damage at both ends. Also your statement about being in 4 wheel drive permanently is incorrect.. The FL1 IS permanent 4WD anyway so irrelevant. The newer FL 2 uses a Haldex unit (IIRC) that only engages when needed(again IIRC)....Haldex is also used on older Audi TT's and some VW '4WD' systems. If an owner wants to they can disconnect the drive shaft completely and fit a blanking plate on the IRD. This makes the FL 1 front wheel drive only. This can be employed in the short or long term although claims of huge saving on fuel costs etc are not really well founded (from comments on here, I have never done this) This 'conversion' can be reversed if needed when a new VCU is located. Any conversion from standard would require the vehicles insurers to be informed.

Maybe if we had a 'database' of figures regarding the 'one wheel up test' it may have some value? However for this to be relevant it would have to be done in a more scientific way with everyone submitting their information after using EXACTLY the same technique and method of measurement. ....but I think the most experienced owners and Freelander Freaks on here have already come up with a 'usable' if not completely objective solution to this issue.

Hope this helps.

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Not sure where you heard they have fibrous plares. They are metal disks with slots in. Replacing the fluid has been done by lots of people including me. I've done it both by cutting the top off, cleaning and rewelding, and drilling holes and flushing.
Best way is to cut the top off but only if your welding is up to scratch, (mine isn't) but either way works.

Alibro said:

Not sure where you heard they have fibrous plares. They are metal disks with slots in. Replacing the fluid has been done by lots of people including me. I've done it both by cutting the top off, cleaning and rewelding, and drilling holes and flushing.
Best way is to cut the top off but only if your welding is up to scratch, (mine isn't) but either way works.

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I may have been looking at my discs in my grinder draw when I was thinking about the VCU but I gather all my other info is more 'corrector' than the other 'posters' comment albeit his comment was from the last decade 'whan I was but a lad'...In the meantime I'm going to click on your avatar and have a laugh.....

Alibro said:

Not sure where you heard they have fibrous plares. They are metal disks with slots in. Replacing the fluid has been done by lots of people including me. I've done it both by cutting the top off, cleaning and rewelding, and drilling holes and flushing.
Best way is to cut the top off but only if your welding is up to scratch, (mine isn't) but either way works.

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Oops, forgot to add this too...

Just to make you feel bad here is someone who does a bit of welding..

Practice makes perfect, as you know...interesting that you've done the VCU 'service' do you think it's a viable procedure???

https://www.youtube.com/channel/UCqq70AnPkj4-UApS_m_6mPw

MollyNomad said:

interesting that you've done the VCU 'service' do you think it's a viable procedure???

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Alibro is probably the go-to man for VCU rebuilds - he's done a few and tested them by trying to get his Freelander stuck, unsuccessfully I believe

So I recon he would say its very viable.

He's getting so good, he's contemplating moving to Scandinavia where all the hardcore VCU rebuilders hang out

GrumpyGel said:

Alibro is probably the go-to man for VCU rebuilds - he's done a few and tested them by trying to get his Freelander stuck, unsuccessfully I believe

So I recon he would say its very viable.

He's getting so good, he's contemplating moving to Scandinavia where all the hardcore VCU rebuilders hang out

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Scandanavia....'Can du snakka Norske'?

Lived there for a time in Norway...winters only it's ****ing boring in the summer..Can't imagine a VCU overheating there anytime except maybe late July early August...Also, if he's done so many doesn't that kind of signify that he buys the worst 'Freelandy' possible to try and get stuck in the mud? He won't get far 'off roading' in Norway, after November....(from personal experience :-S )

Just in case i'm in the wrong country my Swedsih client has suggested this 'save all' cry for help on Swedish roads..

'Jag tror att min freelander har slagit en vattenmelon, kan du hjälpa mig att byta min VCU?'

He also says that is a pretty good chat up line, works well with 'blondes'....(His wife is a brunette BTW!!)

Unfortunately 5kg at 1.2m is only 59Nm pressure. Yer need 90Nm or more to apply pressure to the vcu in it's linear zone to get a reliable result. Hence using 8kg at 1.2m = 9.8 x 8 x 1.2 = 94Nm. If performing the owut in the none linear zone, results vary too much. Even a vcu which has failed and been sat doing nothing for 12 months will give a reliable test result if first turned one whole turn before trying the owut. Graph in post 241.

https://www.landyzone.co.uk/land-rover/vcu-torque-test-results.109486/page-13#post-2141449

@Hippo suggested, and I agree, that peeps supply certain info so that we have a "standardised" set of figures and also for both old and new VCUs, as per the spreadsheet above. Peeps never bothered, or at least rarely bothered, to supply that info.
By all means use the above spreadsheet as a starting point and add any correlated info you find.
I, for one, have a headache from banging my head on a brick wall over the last 10-12 years!
Wonder what @Hippo thinks?

Hippo said:

Unfortunately 5kg at 1.2m is only 59Nm pressure. Yer need 90Nm or more to apply pressure to the vcu in it's linear zone to get a reliable result. Hence using 8kg at 1.2m = 9.8 x 8 x 1.2 = 94Nm. If performing the owut in the none linear zone, results vary too much. Even a vcu which has failed and been sat doing nothing for 12 months will give a reliable test result if first turned one whole turn before trying the owut. Graph in post 241.

https://www.landyzone.co.uk/land-rover/vcu-torque-test-results.109486/page-13#post-2141449

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This sounds like it makes sense but using a 5kg weight still has merit? It's a pity the 5kg weight got mentioned at some time because it is what most people use and as stated the results are variable but it will still tell you what you need to know. IMHO If it takes 3 minutes or more you have a problem and under a minute your golden, inbetween and so long as your tyres are good you should be OK. (But don't quote me on that )
A certain a**hole who frequented these parts last year ridiculed the OWUT as not dynamic (I think that was what he said among other things). Although he was a complete dick he had a point about the test not being accurate as the forces applied by a weight are nowhere near those delivered by the drive train.
TBH I'm not convinced exact figures matter all that much though. If you put a breaker bar on a car with a stiff VCU you'll barely be able to turn the wheel whereas a good VCU will turn relatively easily. This was the point he deliberately ignored, the OWUT is just a way of quantifying the stiffness.

This seems almost scientifickery but from an enthusiasts point of view and experience....I have actually seen the video before posted above when I was 'researching' Freelanders before I went and bought one......All the points regards VCU age, mileage and wear now make sense and that data base (with all the hassles caused etc) would have some merit....if all the info was put in but there are a few variables too...Offroading, **** driving technique etc to name a couple...

I 'get' this completely and is the best we can do without some bloke in a white coat and clip board who eats cheese and wears thick glasses being involved...

GOOD STUFF!

There have been a few of those guys in white coats analyse VCUs over the years - mainly in the 80's I believe when they were 'new tech'. Most of their scribbles were of how they function, but there were some jottings of how they degrade etc. I believe most tested VW couplings.

Ultimately though, a guy in a white coat will only be interested in setting up proper scientifickery testing procedures using labs and lots of expensive kit with flashing lights, twiddly knobs and little 4" CRTs.

If its not dirt cheap/free a test can't be done at home, and if its to complex it won't be done at home. So yeh, the OWUT is not perfect, but its a quick simple test with an immediate quantifiable answer.

The only other test I've heard of that got close was one that @Tony Reeves set up which IIRC used a pole connected somewhere aft of the VCU pressing up on a set of bathroom weighing scales mounted upside down underneath the car. This could test much higher forces up to the levels quoted in the LR workshop tests. I imagine though, if your VCU was to stiff you could easily tell by the fact you needed a new set of scales afterwards!

Hippo said:

Unfortunately 5kg at 1.2m is only 59Nm pressure. Yer need 90Nm or more to apply pressure to the vcu in it's linear zone to get a reliable result. Hence using 8kg at 1.2m = 9.8 x 8 x 1.2 = 94Nm. If performing the owut in the none linear zone, results vary too much. Even a vcu which has failed and been sat doing nothing for 12 months will give a reliable test result if first turned one whole turn before trying the owut. Graph in post 241.

https://www.landyzone.co.uk/land-rover/vcu-torque-test-results.109486/page-13#post-2141449

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Nice data in that post Hippo.

The problem is that 5kg has now passed into "internet lore" and it'll take a lot of effort to change it from the current 5kg at 1.2 metres. Not impossible, but a bit of effort.

5kg is just before the curve becomes linear, so the error should not be too massive. And 5kg is a 5 litre bottle of windscreen wash (or whatever) and so is very easy.

The pragmatic (not scientific) solution is to go with the flow and document what most people do and provide a rough and ready guide of expected wheel rotation times over a 45 degree arc

Also, even at 5kg you need a strong pole and method of connecting it you your ratchet. Bigger weights need more "engineering" skills and beefier kit that may start affecting the weight being applied.

True - my 3/4" bar needed a wooden dowel to extend to 1.2 metres. Managed this with a couple of cable ties - but they'd probably not be man enough for 8kg?

Quick, easy, simple, cheap. 5kg or higher weight? I'd be happy whatever, but it needs to be standardized, and what everyone uses. And seemingly almost everyone currently uses 5kg?

Why not specify a breaker bar? They are obtainable in suitable lengths.

http://www.ebay.co.uk/itm/1M-Long-3...r-bar-39-1M-flexible-handle-bar-/201033875922

Alibro said:

This sounds like it makes sense but using a 5kg weight still has merit? It's a pity the 5kg weight got mentioned at some time because it is what most people use and as stated the results are variable but it will still tell you what you need to know. IMHO If it takes 3 minutes or more you have a problem and under a minute your golden, inbetween and so long as your tyres are good you should be OK. (But don't quote me on that )
A certain a**hole who frequented these parts last year ridiculed the OWUT as not dynamic (I think that was what he said among other things). Although he was a complete dick he had a point about the test not being accurate as the forces applied by a weight are nowhere near those delivered by the drive train.
TBH I'm not convinced exact figures matter all that much though. If you put a breaker bar on a car with a stiff VCU you'll barely be able to turn the wheel whereas a good VCU will turn relatively easily. This was the point he deliberately ignored, the OWUT is just a way of quantifying the stiffness.

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The difference between 5 and 8kg is quite a bit, due to the way the test works.

In simple terms the vcu applies a resistance against the force you apply during the owut. The force you apply can be corrupted due to the way you apply the weight. I have asked people to apply it gently just before 45 degrees, so the momentum of the force starts and is consistent before/when it turns to enter the test period of 45 degrees to horizontal. If you don't do this, and apply the weight at 45 degrees instead, the momentum phase takes place during the test phase and the result isn't comparable as it will take longer as the momentum is building up during the test phase.

A similar problem occurs if the weight is applied by dropping it to let go. The sudden force applied speeds up the weight during the momentum phase (above the speed it would normally be if applied correctly/gently) and the test therefore completes quicker.

These 2 scenario's make results difficult to compare. If applying the weight by dropping it you can speed up the test by about 50%. If there isn't enough force applied (90Nm or above) then there isn't enough momentum to get the test turning fast enough to get the vcu working in the zone where it's results/operation is linear. Hence a longer test time making you think it's failed when it hasn't.

the end result: a bad vcu can be made to look good or bad, depending on how the weight is applied and how heavy the weight is. This can be seen regular by peeps posting values which say the vcu is ok but they have symptoms which display failure. It has failed.

The way round this is to perform the test with 90Nm or more force applied, when the vcu is in what we call it's linear zone. The results are more reliable as the force applied (gentle or dropping) doesn't offset the results as much as it would with lighter weights. It's still betterer to apply the weight as requested for cleaner results. 8kg is easily made up of 5kg bottle of car shampoo or similar. Fabric conditioner comes in 3L or 3kg bottles. 8kg at 1.2m is the same as 5kg at 1.92m by using a longer bar.

As an eggsample... my brand new gkn vcu has now failed. Only because I don't need it so I killed it on purpose as part of me investigations. I turned it constantly at multiple rev's per minute whilst measuring the temp. I performed the owut before and after. It now gives a test result of 60% more (8kg at 1.2m) than what it should, when it were new. This result could easily be corrupted as a pass with 5kg if applying the force in such a way as not to get the momentum going to get a result from the linear zone. Mad I know, but Freelandering is sometimes.

rob_bell said:

Nice data in that post Hippo.

The problem is that 5kg has now passed into "internet lore" and it'll take a lot of effort to change it from the current 5kg at 1.2 metres. Not impossible, but a bit of effort.

5kg is just before the curve becomes linear, so the error should not be too massive. And 5kg is a 5 litre bottle of windscreen wash (or whatever) and so is very easy.

The pragmatic (not scientific) solution is to go with the flow and document what most people do and provide a rough and ready guide of expected wheel rotation times over a 45 degree arc

Click to expand...

Unfortunately 5kg at 1.2m can provide a result which is out by too much without the user realising. If yer have a look at the post I wrote'd above to alibro it explains it. 8kg can be made from 5kg of shampoo and 3kg or 3L of fabric conditioner.

GrumpyGel said:

Also, even at 5kg you need a strong pole and method of connecting it you your ratchet. Bigger weights need more "engineering" skills and beefier kit that may start affecting the weight being applied.

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I have applied 26kg while bench testing it on it's own and it were quick. Me bar didn't bend but one of the tie wraps gave up.

The Mad Hat Man said:

@Hippo suggested, and I agree, that peeps supply certain info so that we have a "standardised" set of figures and also for both old and new VCUs, as per the spreadsheet above. Peeps never bothered, or at least rarely bothered, to supply that info.
By all means use the above spreadsheet as a starting point and add any correlated info you find.
I, for one, have a headache from banging my head on a brick wall over the last 10-12 years!
Wonder what @Hippo thinks?

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I think we're mad. I try not to respond to vcu fred's but sometimes the inner self in me gets the betterer of me judgemint.

We've re-invented the wheel too many times before. There's far too much discussion on ere and not enough results. Often it ends in arguments. Then the tratterers join in and drop bits of rust everywhere. We've spent far too long trying to get peeps to perform the test. Far too much time has been spent talking about the fact the owut test isn't perfect, but it's the best we have. Having to defend the test has wasted too much time. Someone will be along to tell us all we need to do is it put a bar in the UJ and see if it turns. If it does it's ok...

I get a lot of pm's asking questions about vcu's and auto gearboxes. Probably due to all the sh*te I've posted on ere over the years. After all these years I still feel upset when replying to explain why their ird/rear diff is cracked because... their auto gearbox is feked because of low oil... wrong nut removed... This could have easily been avoided. Even LR magazines point vcu related topic's to the owut test and this ere forum + the work we tried to do. It doesn't help when re-conners use sweeping statements to take a chunk out of our efforts, for their gain.

If I were asked 10 years ago how many results I think we would have had by now... I would have given the answer in the thousands.

50k and 46k views on me vcu owut video's
11k views of a turning cracked ird
34k views of peeps watching custard powder seeping out me vcu...

If yer do a search on me posts in ere for the word COOKIE yer''ll find lot's of replies I've made to peeps who have posted owut result. I gave them a cookie for doing so. I think many of the replies have fallen oft the edge of LZ. But there's some left.

https://www.landyzone.co.uk/search/6119708/?q=cookie&o=date&c[user][0]=13135

5kg at 2m?