VCU Torque test results

4flats said:

How about one fat guy standing on a tire iron 90 deg, no wheel movement 20 seconds? I think I am going to pull it tomorrow.

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Hi. Lift up both rear wheels and turn 1 wheel. The other will turn in the opposite direction. This will confirm the rear brakes int sticking and the hand brake int stuck on. Also are you sure the wheel you were trying to turn with the tire iron was raised oft the ground, with the hand brake released? If the wheel turns ok with both rear wheels oft the ground and you can’t turn the wheel with the tire iron when performing the One Wheel Up Test then I would suggest you remove 1 prop or the props/vcu as a complete set and investigate further, as not being able to turn the wheel during the test would suggest your vcu is seized. You should check again and remove bits sooner rather than later if there's a problem, to reduce the chances of stress in yer transmission feking the ird and/or the rear diff if yer vcu is seized.

As soon as my V6 is sorted I'll post the findings
Won't be long as the Mot is Monday!!

Hippo said:

Hi. Lift up both rear wheels and turn 1 wheel. The other will turn in the opposite direction. This will confirm the rear brakes int sticking and the hand brake int stuck on. Also are you sure the wheel you were trying to turn with the tire iron was raised oft the ground, with the hand brake released? If the wheel turns ok with both rear wheels oft the ground and you can’t turn the wheel with the tire iron when performing the One Wheel Up Test then I would suggest you remove 1 prop or the props/vcu as a complete set and investigate further, as not being able to turn the wheel during the test would suggest your vcu is seized. You should check again and remove bits sooner rather than later if there's a problem, to reduce the chances of stress in yer transmission feking the ird and/or the rear diff if yer vcu is seized.

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Pulled whole asymbly, huge difference in how it drives!

4flats said:

Pulled whole asymbly, huge difference in how it drives!

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Try to put 2 long screw drivers or whatever you've got handy through the 2 uj's either side of the vcu now it's off. You should be able to turn 1 while holding the other. If you can't, then this will confirm what we're already thinking, yer vcu is somehow seized. If so, then you've had a lucky escape from transmission problems. Well spotted. It just goes to show how important it is to check yer vcu.

Did a quick VCU test today. I only had time to do a 10Kg test. My car is 2001 V6 with 31500 miles on it.
10 Kg's @ 1.2M = 11 seconds

Nodge68 said:

Did a quick VCU test today. I only had time to do a 10Kg test. My car is 2001 V6 with 31500 miles on it.
10 Kg's @ 1.2M = 11 seconds

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Thanks. Ere’s a cookie for yer valued efforts.

I have done the test today, in my auto td4.

I done it in neutral because only now, i realized you are doing it with a gear engaged, if i'm not wrong. But I think it doesn't have any influence.

Anyway, it took 130seconds whith 8kg to do the 45º test.

I guess is getting too tight, as i suspected.

The car and the vcu has about 72000 miles.

Nitrous said:

I have done the test today, in my auto td4.

I done it in neutral because only now, i realized you are doing it with a gear engaged, if i'm not wrong. But I think it doesn't have any influence.

Anyway, it took 130seconds whith 8kg to do the 45º test. EDIT: [1.2m bar]

I guess is getting too tight, as i suspected.

The car and the vcu has about 72000 miles.

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130 seconds for an 8kg weight to turn 45 degrees to the horizontal is a long time when comparing results from others. How long was the bar?

Doesn't matter if auto or manual gearbox, or if it's in or out of gear. Make sure the hand brake is off and not stopping the rear wheel turning. You can do this by lifting both rear wheels and check they spin freely.

Thanks for doing the test. Here's a cookie.

I tried to replicate your test with a 1,2m long bar.

Nitrous said:

I tried to replicate your test with a 1,2m long bar.

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Well done. Your very lucky to do the test and find a result which is quite high. You may have caught it in time and saved youself an expensive repair. We don't have enough results to know what the average range of values are. It's mainly the new members on here who do the test. The results we get, the better.

If you still have the vcu fitted can you measure the temperature after a short drive and let us know? Also tell us the distance travelled and the typical speed. Then remove the vcu so it can't cause you any problems. Thanks.

I don't have how to check the temperature.

Nitrous said:

I don't have how to check the temperature.

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Leave your Freelander stationary so the vcu cools to ambient temp. Takes several hours.
Measure the vcu temp with a thermometer. We use infra-red thermometers and shine it against the circumference side of the vcu. You can use a normal mercury thermometer if you like. Hold the end/side against the vcu and then cover with a cloth so it measures the temp of the vcu more.
Measure the bodywork of your Freelander to give you an ambient temp. Measure the metal door that’s not in sun light.
Drive your Freelander and record the miles and speed. Example 40mph for 3 miles and 50mph for 1 mile.
Measure your vcu temp again.
Supply the results: start temp, end temp, ambient temp and miles/speed driven.

We call this the “Turnip Test”.

It's a bit mad but this test tells us what the vcu is doing. It's the only test that warns you if theres a problem with the vcu, tyres or brakes which is causing the vcu to work harder. The hotter the vcu gets while your driving, the more work we think it's doing.

Regarding the shearing effect, does this really happen?

Wouldn't the result be the same if the VCU gunk is just a really thick gooey oil that gives just enough resistance to cause the rear propshaft to turn slower than the front?

This would also result in the desired drive effect surely when the front wheels slip and the rear ones don't, and would also heat up given the friction generated when the torque exceeds the twist threshold?

I dunno - just trying to make sense of it in my tiny brain...

bukko said:

Regarding the shearing effect, does this really happen?

Wouldn't the result be the same if the VCU gunk is just a really thick gooey oil that gives just enough resistance to cause the rear propshaft to turn slower than the front?

This would also result in the desired drive effect surely when the front wheels slip and the rear ones don't, and would also heat up given the friction generated when the torque exceeds the twist threshold?

I dunno - just trying to make sense of it in my tiny brain...

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No

The Mad Hat Man said:

No

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Ditto! It'd lubricate it and you'd have no drive!

Just repeated the test with weights on a 1.2m bar.
Results from September are
With 9.3Kg took 12.3 seconds and 5.5Kg took 31 seconds.

Results now are
With 9.3kg took 18 seconds and 5.5kg took 53 seconds.

I have tested it in between but only bothered torque test. It feels a bit stiffer so I tried the weight test again.

I think it may have been a thrashing I gave it trying to get up a muddy hill that may have worn it a bit (burnt clutch out aswell during this, good thrash at 4000 revs and I didn't know if wheels or clutch was slipping). Do you think a good workout like spinning wheels could shorten the life of the VCU?
Not sure what to do now, but will keep an eye and ask the mechanic to check it out when he does the clutch. At least it's not solid.

Just another thought - I have lifted it by 40mm lift kit lately - could drive shaft angle into rear diff cause more resistance?

chris2000 said:

Just another thought - I have lifted it by 40mm lift kit lately - could drive shaft angle into rear diff cause more resistance?

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Mines a 50mm lift and the inner joints bind at full droop!

chris2000 said:

Just another thought - I have lifted it by 40mm lift kit lately - could drive shaft angle into rear diff cause more resistance?

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Lift up rear end so both wheels are oft the ground. Turn one and the other will turn in the opposite direction. See what the resistance is.

This might be a really thick question? so no doubt will get some sort of rude response, any way here goes. Has any body spoken to Land Rover and told them that we are not happy that the vcu is none repairable also what should be the optimal time for the weight test or how is the best way to test it.:behindsofa: