Updated August 2016

Ere's the results of testing my Freelanders VCU using the One Wheel Up Test.

A quick refresher of what we're trying to achieve ere:

Q. What vehicles do the test results apply to?
A. Freelander 1. Other vehicles fitted with VCU's can perform the same test, but their results will differ due to rear diff gearing and their vehicles VCU design characteristics.

Q. Why are we doing this test?
A. To collate results from different VCU's in order to see if there’s a common result trend.

Q. What would we like to get out of the results?
A. Hopefully a common trend which members could compare their test results too, in order to spot premature failure of VCU's before they fek up their Freelanders transmission (possible failure of IRD and/or rear diff).

Q. What does the test do?
A. It applies a known steady pressure (force) to the VCU (via the rear diff) while we time how long it takes for the bar to turn 45 degrees to the horizontal. This will give us a value in seconds we can use to compare different VCU's, whilst performing the same test.

Q. How do you do the test?
A. Chock front wheels. Release handbrake. Doesn't matter if it's a manual or automatic gearbox, or what position the gearbox is in. Jack up one rear wheel. Remove plastic centre wheel cap. Fit a 1.2m bar (made up of ratchet and wood) with a 32mm socket on the drive shaft nut. Raise bar and add a known weight (8kg is preferred). Allow the bar to start turning before the 45 degrees start point, in order to take out the slack in the transmission. Time the bar while it turns 45 degrees to the horizontal. Use masking tape markers to help you with the 45 degrees and horizontal stop/start positions.

Q. What's your bar made of?
A. 32mm socket, small metal extension bar, ratchet to attach the length of wood to the drive shaft nut and length of wood with a nail in the end. Use several tie wraps to secure the wood to the ratchet. Measure a distance of 1.2m from the pivot point (extension bar) to the end of the wood. Cut the wood at the 1.2m point and put a nail in the end to use as a hook. Apply known weights to the end of the wooden bar (I used tie wraps hooked over the nail).

Q. Why have you repeated the test with different weights?
A. This gives an overall view of the performance of the VCU with different weights applied. It also allows us to compare other peeps results if they've used a different weight. 8kg is still the preferred weight to use as this applies pressure to the vcu in the linear result region. 1kg = 1 litre of water. if

Q. Can I do the same test too?
A. Yes. If we all carry out the same test and pool our results we will gain a better feeling of the average time to perform the test, as a comparison against others.

Q. Can you perform a similar test on a VCU on a bench?
A. Yes. I have done this already and will put up the results soon after editing the video. I will edit this post and add the results at a later date. I will also add another post to this thread to confirm when this has been done.

Q. If my One Wheel Up Test time is high and I want to remove my VCU for peace of mind (until I get a replacement, or I may just leave it off for a while), how would I do this myself?
A. Follow the link below. It's easier to remove the VCU and both prop shafts at the same time when doing it at home. If you do this you will need to advise your insurance company as it's considered a modification. The link provides the method of removal, changing the support bearings and refitting.
https://www.landyzone.co.uk/land-rover/freelander-1-vcu-bearing-replacement-how-to-guide.156068/

Q. What should I do if my test result is higher than yours?
A. Ideally someone performing the test would do the same test a few times to make sure they get a similar result each time. If the result is high then I would do the following:
  • chock the front wheels and release the handbrake
  • lift both rear wheels off the ground
  • turn the rear wheel you were using for the One Wheel Up Test to check it turns freely.
Don't be surprised when turning the rear wheel when you see the wheel on the other side turning in the opposite direction. This is because the rear prop to rear diff connection isn't turning. This is correct, as you're turning the opposite wheel via the rear diff internal gears. When the rear diff is being used in normal on road operation the rear prop to rear diff connection is turning, which allows both rear wheels to turn in the same direction. The internal rear diff gears then allow both rear wheels to travel at differing speeds to allow for cornering.

Q. Referring to the last question, I would prefer to lift both wheels on the same side, if I need to check the handbrake has released, to check the wheel being tested turns freely, as I feel safer.
A. Yes you can do this if it makes you feel safer. This will only test the handbrake is released on the lifted rear wheel. This is all you need to know for the test. The method would be:
  • chock both front and rear wheels which will remain on the ground, on the same side of the Freelander
  • release the handbrake and put the auto gearbox in neutral (neutral for manuals too)
  • lift both wheels on the other side and turn the rear wheel. The front wheel will then turn in the same direction (assuming the props/vcu are fitted and the rear diff/ird are working correctly). It takes a little bit more effort than turning both rears, but easily possible by hand.


Test results:

My VCU's temperature measured 23 degrees before and after the testing. VCU temperature is an important factor which will produce different results, for the same VCU. My Freelander hadn't been driven over night to allow the VCU to cool to an ambient temperature. At the time of testing my VCU was 11.5 years old. It's an original Land Rover VCU supplied when my Freelander was manufactured in 2001. It's stamped GKN. Current mileage at the time of testing was 32,000 miles. My Freelander is a 2001 Freelander 1 v6.

Weight in kg / Time in seconds

3.0 kg . . . . . . . 80.0 seconds
4.1 kg . . . . . . . 49.5 seconds
5.0 kg . . . . . . . 35.5 seconds
6.2 kg . . . . . . . 25.0 seconds
7.1 kg . . . . . . . 20.0 seconds
8.0 kg . . . . . . . 16.0 seconds
8.9 kg . . . . . . . 14.0 seconds
10.0 kg . . . . . . 12.0 seconds
11.0 kg . . . . . . 10.0 seconds
12.4 kg . . . . . . 8.0 seconds
13.8 kg . . . . . . 7.0 seconds

Ere's a video I made during testing:

One Wheel Up Test Results - Viscous Coupling Unit VCU Torque Test - Freelander 1

Ere's a graph of my results. Blue X is my measured results. Green line shows an estimated curve for my VCU.

The graph shows a curve (non linear) and straight line (linear) sections. OWUT results should be done in the linear section for more precise, reliable results. You will get more reliable results with 8kg on a 1.2meter bar, when compared to 5kg at 1.2meter bar.

3paXgcc.jpg

OneWheelUpTestResultGraph 3paXgcc

********
Bench test figures in this post are approx to about the nearest second. Figures are the same when my vcu was brand new and after a few thousand miles. I will put a full list up when i get round to editing the video.

The test is all about force applied
force in Nm applied = length of bar x 9.8 x weight on bar

owut with 5kg on a 1.2m bar is 35.5 seconds
bench test on vcu with 5kg on a 0.38m bar is approx 41 seconds

owut with 8kg on a 1.2m bar is 16 seconds
bench test on vcu with 8kg on a 0.38m bar is approx 20 seconds


Hi,

about to do the test on mine and have a couple of Qs

1) is there a +/- for each set of weights outside which it is a fail
2) which is worse a greater or shorter time
3) which is the best temp A)1st thing in the day before it has been driven, B) after a short run (5mls) C) after a long run.

It is my second vcu 1st one went at 108k took out IRD. It is on 160k now

Have had the vehicle from new its 21st birthday is 1/8/21 2 days time! Did 80K in 2 1/2 yrs now 160K.

cheers
terrier
 
Hi,

about to do the test on mine and have a couple of Qs

1) is there a +/- for each set of weights outside which it is a fail
2) which is worse a greater or shorter time
3) which is the best temp A)1st thing in the day before it has been driven, B) after a short run (5mls) C) after a long run.

It is my second vcu 1st one went at 108k took out IRD. It is on 160k now

Have had the vehicle from new its 21st birthday is 1/8/21 2 days time! Did 80K in 2 1/2 yrs now 160K.

cheers
terrier
The test provides the time taken to complete said test. If it takes longer then yer vcu is stiffer, which is bad news. They will stiffen with use or if they're abused.

If the test result is quicker then yer vcu is slipping more than an original LR once fitted. A lot of recon units do this. It's not a problem. It just means yer vcu may not activate as soon as desired when needed oft road. Some slip all the time making them useless at providing 4x4 when needed.

Compare your time to results from others. The test is designed to be repeated regular. If your test time starts moving (taking longer) on future tests then it's a sign yer vcu is starting to change and therefore past it's best, and should be removed/replaced.

Searching my posts for the word 'cookie' in the Freelander section will provide you with a lot of results. There's many other freds discussing results anorl.

https://www.landyzone.co.uk/search/153868667/?q=cookie&o=date&c[node]=9+69&c[user][0]=13135
 
Hi,

about to do the test on mine and have a couple of Qs

1) is there a +/- for each set of weights outside which it is a fail
2) which is worse a greater or shorter time
3) which is the best temp A)1st thing in the day before it has been driven, B) after a short run (5mls) C) after a long run.

It is my second vcu 1st one went at 108k took out IRD. It is on 160k now

Have had the vehicle from new its 21st birthday is 1/8/21 2 days time! Did 80K in 2 1/2 yrs now 160K.

cheers
terrier
1) Timings of a "fail" isn't a precise thing, just "guidance". If you look back over the previous 2 pages discussing the timings @kernowsvenski found - that really gives about as gooder guidance as you'll get.

2) As above, a shorter time indicates your VCU isn't giving you 4WD/AWD capability but won't break anything. A to greater time does not give you improved 4WD capability, but will break expensive things (as you've found!).

3) I'm not sure what's the best. A VCU that has been standing for a while will give you inaccurate reading when you do a test - so you need to do a number of tests and see what it settles at. Taking the car for a short drive may be advisable to get the VCU into its 'driving' condition - however, even then, don't do just 1 test, do multiple tests in case 1 is wrong (eg start/stop pos was misjudged).
 
One full turn is enough to spread the fluid round a vcu which has been sat for a few days or a lot more. If you test it constantly test after test... you'll find 3 tests will turn it enough to get the test results to provide a constant reading of the same value after that if done the correct way. The fluid doesn't chemically separate. It very slowly sinks to the bottom of the vcu. Ambient air temp is ok for testing. You don't need to warm it up or anything. I always do mine from standing for a few hours at least. there's also the 'Turnip Test' you can do anorl.
 
Okay. been following this for a while. Bought a 3 Door 2004 Hippo. About 2 years ago. Add Covid and a divorce, only getting her sorted now. Through MOT yesterday (yes a Sunday. we have a 4 month waiting lists on MOT dates here. it is mental...
Couple things needed for re-test in 2 weeks, but nothing to worry about.

The VCU worries me. She needed a recon rear diff, as well as all new mounting, 2 x carrier bearing on the drive shafts, all new tyres front and back. Think that the VCU may be an issue, and going to do the test. But with so many opinions and such like on here. looking to know what is the best single test to give a guide to how the VCU is.

I appreciate it will only be a guide, and not definitive. but at the moment I have no idea if its knackered bad or knackered good.

What length (See 1.2 m stated a lot) and weight. and expected durations to move 45 deg with 1 wheel up.
And what direction the wheel turn. Clock wise or anti clockwise?

I also have 2 other out of the hippo VCU Units, what is best way to test them on the bench??

And anyone got a nice set of leather seats for a 3 door, 2004 Freelander 1 Face lift??

Thanks in advance

Alex
 
Ohh , forgot to mention.

She's hard to get into gear (Consider this a new clutch job, so not really a concern). But in turn, there is a bit of a hum, which seems to be the gearbox or IRD. Clutch in no hum, freewheel, no hum. So not likely a bearing or diff. Going to get mechanic to do a drive in her and his opinion. Replacement box and/or IRD is acceptable within overall costs to get her on the road. Anyone any opionion on that, would it be related to a knackered VCU?
 
Okay. been following this for a while. Bought a 3 Door 2004 Hippo. About 2 years ago. Add Covid and a divorce, only getting her sorted now. Through MOT yesterday (yes a Sunday. we have a 4 month waiting lists on MOT dates here. it is mental...
Couple things needed for re-test in 2 weeks, but nothing to worry about.

The VCU worries me. She needed a recon rear diff, as well as all new mounting, 2 x carrier bearing on the drive shafts, all new tyres front and back. Think that the VCU may be an issue, and going to do the test. But with so many opinions and such like on here. looking to know what is the best single test to give a guide to how the VCU is.

I appreciate it will only be a guide, and not definitive. but at the moment I have no idea if its knackered bad or knackered good.

What length (See 1.2 m stated a lot) and weight. and expected durations to move 45 deg with 1 wheel up.
And what direction the wheel turn. Clock wise or anti clockwise?

I also have 2 other out of the hippo VCU Units, what is best way to test them on the bench??

And anyone got a nice set of leather seats for a 3 door, 2004 Freelander 1 Face lift??

Thanks in advance

Alex
Rear diffs seldom fail, noise which sounds like the diff is often the VCU support bearings.

Follow the one wheel up test on here to get an idea as to the VCU's condition.

Also work putting what engine you have down, as things like clutches and gearboxes vary depending on engine type. ;)
 
Carrier bearings for VCU already replaced. Rear diff was knocking and clunking and needed replaced, with all new Mountings. That's done.

Hum not from Bearings to VCU or DIFF. Only appears when in gear and under throttle. I am swaying towards IRD or box. or if I am really unlucky, both.
 
Kinda defeats the work i've done if I disconnect therear prop shaft.....TD4 2.00 Diesel.

At what I bought her for, and the cost to date, she'd worth forking out for a recon IRD if I have to. Just trying to figure out ways of checking if IRD or box. Pretty sure its one or the other. VCU check now to do later in the week. Watched hippos video on you tube. (Thanks hippo). Also saw a video how to test VCU on the bench. I'll test the other 2 I have to see if any are of any use.
 
Like Nodge says, temporarily removing the propshaft will save your Diff if the VCU is tight. Most times the diff in a Freelander fails it is because of the VCU being over tight. Testing it is really simple. Jack up one wheel, put a large socket on the centre bolt or if you don't have a socket big enough use one of the wheel nuts. If you can make the wheel turn slowly using reasonable force then it's not seized. If you cannot shift it then get the prop off immediately.
Bare in mind the test requires 5kg at 1.2m from the centre of the wheel so that is the kind of force considered reasonable.
 
+1 for 5kg weight at 1.2m from the wheel centre. Release it from somewhere higher than 45 degrees, so that you can start timing as it passes the 45 degree line. Stop timing when the bar is horizontal. I'm told that anything over 1 minute under those conditions, is bad. I don't think it makes any difference which wheel you use or in which direction, but I usually use a rear wheel in the forward direction.
 
+1 for 5kg weight at 1.2m from the wheel centre. Release it from somewhere higher than 45 degrees, so that you can start timing as it passes the 45 degree line. Stop timing when the bar is horizontal. I'm told that anything over 1 minute under those conditions, is bad. I don't think it makes any difference which wheel you use or in which direction, but I usually use a rear wheel in the forward direction.
5kg offers a result outside of the non linear section of the result graph. It's not enough force to get it moving reliably. Use 8kg at 1.2m bar.
 
5kg offers a result outside of the non linear section of the result graph. It's not enough force to get it moving reliably. Use 8kg at 1.2m bar.
OK, thanks. The only reason I used 5, was because there were a number of figures for the time for 5kg floating around the internet to compare, but 8kg is easy enough. Do you have any times for a healthy one with an 8kg weight, please?

Also, I'm not sure I understand the non-linearity bit, because it's a non-linear test anyway, regardless of what weight you use? When the bar is horizontal, 5kg at 1.2m exerts a torque of 5 x 9.81 x 1.2 = 59Nm on the hub. But when the bar is at 45 degrees, the torque on the hub is 5 x 9.81 x sin 45 x 1.2 = 42 Nm. It varies as part of a sinewave between those two angles.

(Not that any of this matters to me just now, because the bloody thing is stuck in Spain with a cooked clutch)!:(
 
"Do you have any times for a healthy one with an 8kg weight, please?"

My Daughter's - 10k on a new GKN VCU -25s @ 5Kg 12s @ 8KG
Mine at 130k - 28s @ 5Kg 12s @ 8Kg
Mine at 140K - 30s @ 5Kg 13s @ 8Kg
(from the date on my VCU it's original 2005)
Must have had matching tyres all it's life - not just with me
 
OK, thanks. The only reason I used 5, was because there were a number of figures for the time for 5kg floating around the internet to compare, but 8kg is easy enough. Do you have any times for a healthy one with an 8kg weight, please?

Also, I'm not sure I understand the non-linearity bit, because it's a non-linear test anyway, regardless of what weight you use? When the bar is horizontal, 5kg at 1.2m exerts a torque of 5 x 9.81 x 1.2 = 59Nm on the hub. But when the bar is at 45 degrees, the torque on the hub is 5 x 9.81 x sin 45 x 1.2 = 42 Nm. It varies as part of a sinewave between those two angles.

(Not that any of this matters to me just now, because the bloody thing is stuck in Spain with a cooked clutch)!:(
There's a graph link in me sig. Also ere:

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

Look at the graph. 8kg onwards is linear, as in straigh line. The graph is made up of a straight line and a curve. The vcu needs tested to see if it will turn, and do so at a reasonable pace, on the straight line. 8kg puts 94Nm at 1.2m bar while horizontal will do this. This is enough to get it turning on the linear line. When a vcu is past its best it wont take long for its test result to increase. Hence creeping up the curve to match values on the curve where smaller weights are tested.

8kg a 1.2m bar is 94Nm when horizontal. Origionally woodern bar as its easier to compare over metal types that can be much heavier and therefore add more to the weight applied. We name it as 94Nm applied when horizontal as its too difficult to explain to peeps about the varying force applied while it turns.

The 5kg 8kg battle has gone on for some years. The last discussion there was a peep putting up results and others said they were ok. I disagreed and he tested again, with different timings. The test result can too easily be oft set by over dropping the weight to start the test, or starting it more sooner than others, that can slow it down as the bar is too near verticle. Which is why i dislike the 5kg 1 minute option. It allows the test time to near double which is too much of a risk. The 'drop' start varies the result more on 5kg than 8kg. Also i would fail an 8kg test well before it's timing doubled.

The test is designed to be a comparison to others but more importantly something you can do regular with your own serup to compare yer own timings of how yours operates and changes. Some vcu reconners admit they 'loosen' up vcu's to reduce stress in yer FL1's transmisdion when used. They also ask owners not to add results of it to our testing as vcu arguements always kicked oft on ere years ago with companies being slagged.

There's another vcu test I also use which backs up the above but i haven't put it up on ere yet. One day...

Sorry to hear of yer clutch problems.
 
There's a graph link in me sig. Also ere:

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

Look at the graph. 8kg onwards is linear, as in straigh line. The graph is made up of a straight line and a curve. The vcu needs tested to see if it will turn, and do so at a reasonable pace, on the straight line. 8kg puts 94Nm at 1.2m bar while horizontal will do this. This is enough to get it turning on the linear line. When a vcu is past its best it wont take long for its test result to increase. Hence creeping up the curve to match values on the curve where smaller weights are tested.

8kg a 1.2m bar is 94Nm when horizontal. Origionally woodern bar as its easier to compare over metal types that can be much heavier and therefore add more to the weight applied. We name it as 94Nm applied when horizontal as its too difficult to explain to peeps about the varying force applied while it turns.

The 5kg 8kg battle has gone on for some years. The last discussion there was a peep putting up results and others said they were ok. I disagreed and he tested again, with different timings. The test result can too easily be oft set by over dropping the weight to start the test, or starting it more sooner than others, that can slow it down as the bar is too near verticle. Which is why i dislike the 5kg 1 minute option. It allows the test time to near double which is too much of a risk. The 'drop' start varies the result more on 5kg than 8kg. Also i would fail an 8kg test well before it's timing doubled.

The test is designed to be a comparison to others but more importantly something you can do regular with your own serup to compare yer own timings of how yours operates and changes. Some vcu reconners admit they 'loosen' up vcu's to reduce stress in yer FL1's transmisdion when used. They also ask owners not to add results of it to our testing as vcu arguements always kicked oft on ere years ago with companies being slagged.

There's another vcu test I also use which backs up the above but i haven't put it up on ere yet. One day...

Sorry to hear of yer clutch problems.


OK, I think I can see what you're getting it, but I'm going to be cussed here, and play Devil's advocate for a bit...;)

Here's your graph:

3paXgcc.jpg


and I think what you're saying, is that the straight line for the overall time taken to complete the test, starts after about 8kg? Fair enough, BUT...

The time gets so much shorter, that small errors with the stopwatch have a much bigger effect on the result. I think that's the downside of using a heavier weight. So, for example, taking dfossil's 30 seconds at 5kg result, if I was even a whole second out with the stopwatch, it wouldn't really make much difference to the overall result. However, a second out on the 13s at 8kg is a much bigger percentage error. On the other hand, a false result due to a slightly binding brake, tight rear diff or propshaft bearing, etc, would have a bigger effect on the result of a 5kg test than an 8kg test. (I just like 5kg because it's a handy 5 litres of water)!

I'll try 8kg next time I see the car, and see what sort of numbers I get.

As an aside, I was tying myself in knots, trying to work out how much torque normally passes through the VCU? Obviously, running in a straight line, with correctly sized tyres, it will be next to nothing, but what's the worst case? The engine can manage 260Nm of torque. I don't know what first gear ratio is, but the 260 would be multiplied by that, as a worst case (or maybe reverse, is the worst case)? So, for example, if first is 3.5 : 1. the 260 Nm from the engine becomes 260 x 3.5 or 910 Nm. But then what happens? Is it fair to say up to half of it goes to the front wheels and half comes out of the back of the VCU? Is there another multiplication inside the IRD first? There's obviously a multiplication in each final drive too.

The reason I'm asking, is to try to get a feel for where the 95Nm peak torque from the 8kg weight sits, in relation to what the VCU might be transmitting in real life. Intuitively, I'd have thought that 94Nm (from the 8kg on the 1.2m bar) on one back wheel, will end up being divided by about 3.5 through the rear diff, so, about 27Nm going into the VCU. No idea if that's correct, though!

Clutch? Bah! Don't talk to me about clutches! My parents ended up deciding to get it fixed in Spain, rather than scrap the car, but the final bill (the garage said the DMF was cream-crackered too), ended up coming to €2000 Euros!:(
 

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