VCU Disaster averted!

Hi all,
After my self inflicted gearbox woes, my worries about the VCU wouldnt go away. I've had the car 4 weeks, and I'm certain that the "drag" or braking effect on tight slow full lock turns was just too much. This was further confirmed by doing the same tests in a mates car, same age, that had a replacement vcu a year or so back. The tippex test on mine showed no relative movement between rear and front prop sections at all, no matter how much tight turning, going round and round slowly was done.
I spoke then to a guy at David Beaumont Transmissions, who is very local, and he said dont drive it anymore. So off with the prop there and then.
What a difference! Noises and harshness effects, which I put down to "its a bit tired at 8 years old" and being used to an old Disco and S111 before gone!
I'm currently driving it FWD only, but intend to pick up and fit a recon VCU from Beaumonts in Halifax on Monday, with new support bearings of course.
Anyone on here had a VCU from them?
Expensive IRD and Rear Diff failure hopefully averted as both seem smooth and free of backlash or other looseness or tight spots and no nasties in the oils which have been drained and changed in readiness.

If your Hippo is at or near the danger milage as mine is i.e 70k then £250 ish for a recon vcu and another 70k is good insurance, my prop was off and VCU seperated in 40 mins flat! Expect refit to take no longer.
Cheers all.

Can yu please do the torque test on both and post the results on the results thread, so we can see what a new and a locked vcu give.

I'll clamp them in a vice at work, and attempt the torque test. I'll put a breaker bar with a known weight on the end and time the swing of the bar through an angle. I'll post all the relevent measurements on here and if someone wants to do the sums I too would be very interested. I will ask at Beaumonts how they test and be cheeky and try and get them to do it first though. The offer of free publicity often helps!
Regards

yu will need to apply a steady 9.2Nm torque to the device. Hippo did this by applying 8KG to the end of a 1.2 metre bar.
I have copied his info into here......

http://www.landyzone.co.uk/lz/1232222-post17.html. But you might want to study the whole thread......

I am not sure what effects a different Torque would do and whether it could be compared.

Riverside said:

I'll clamp them in a vice at work, and attempt the torque test. I'll put a breaker bar with a known weight on the end and time the swing of the bar through an angle. I'll post all the relevent measurements on here and if someone wants to do the sums I too would be very interested. I will ask at Beaumonts how they test and be cheeky and try and get them to do it first though. The offer of free publicity often helps!
Regards

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I wouldnt Use Beumonts m8. I bought one from them about 7 months ago. Its only been on the car around 3 months due to other issues with the drive train. The VCU i got from them has no drive through it IE: no 4wd when the front wheels slip. Steer clear m8.

2001ytd4 said:

I wouldnt Use Beumonts m8. I bought one from them about 7 months ago. Its only been on the car around 3 months due to other issues with the drive train. The VCU i got from them has no drive through it IE: no 4wd when the front wheels slip. Steer clear m8.

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That's interesting. The vcu has failed open circuit if I understand correctly?

Hippo said:

That's interesting. The vcu has failed open circuit if I understand correctly?

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looks like it. Stupid me i didnt send my old VCU back top them so no warranty. Im happy running it as is though until i can afford a new one. At least its not siezing up.

Been thinking about this ere vcu discussion. Has anyone ever cut open a failed vcu to see eggs-actly why it failed? Either mechanical destruction inside (guessing something could go wrong like plates jamming up/falling apart) or liquid problems inside etc? I’ve seen the vcu photo’s floppy’s previously posted, with the cut open vcu with red paint along the cut. But not sure if this was a failed device or not. Just an idea. Naturally I wouldn’t want to tread on the toes of our resident eggspert rippedoff, who I’m sure would know the answer to this idea.

Got an angle grinder if anyone wants to donate a known failed vcu. Naturally it will be beyond whilst cutting it open.

Floppy, I’ll redo the test I did before, with different weights, to see the difference. Will film it so I can get precise times for us to compare. Thinking of something like 4, 8 and 12kg to start with and see how it goes. Will mark the angles this time.

Fluid degrades and goes solid supposedly

Hmmm, no rear drive with a Beaumonts VCU, so thats 1 against them 0 recomendations so far. Just a one off duff one?
If they've sold something that obviously does not actually couple the drive to the rear, then surely they are misrepresenting their product, so the courts would take a very dim view of it, exchange unit given or not. I would be giving them some hassle and mentioning Trading Standards and bad publicity in the mags and forums etc......
I gather they offer two versions of VCU, one of which is more "slippy" and a standard one.
Beaumonts would be more convenient for me as they are only 15 miles away, no hassles with couriers etc. Will still pay em a visit I think and get some answers.
regards, Bill

I have emailed them with no reply.

I've spoken this morning to Bell Engineering, basicaly they've got my business. Very forthcoming when questioned. Also guarantee their units for 12months or 60k miles. None on the shelf at the moment, so I'll stick with 2WD for the next few days.
There's no snow forcast is there?
Cheers all.

They only charge £200 for a unit too. Beaumont charge £250 with no damper ring.

I emailed them end of last week and still have had no reply.

AVOID THESE .

Riverside said:

I've spoken this morning to Bell Engineering, basicaly they've got my business. Very forthcoming when questioned. Also guarantee their units for 12months or 60k miles. None on the shelf at the moment, so I'll stick with 2WD for the next few days.
There's no snow forcast is there?

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Just got off the phone with david beaumont. He told me it was tough **** that my VCU doesnt give drive to the rear wheels and that they sell "Loose" VCu's to stop damamge to the IRD unit.

No where in his advert for VCU's does it state that the ones he is selling will not give drive to the rear wheels. he offered me a heavey duty one in exchange for my old unit and the unit i didnt send back to him originaly.

What a tosser.

I wonder if trading standards would be interested in this?

So - he is selling fuct VCU's to gullible peeps that cant check? Sounds like Trading Standards to me

My Bell Engineering recon is on and works just as it should. I was able to spin the front wheels, well more of a scrabble, as the TC cut in, when pulling out of the 1in 3 gradient out of my lane onto the main road, when only 2wd. Now with 4wd back no such problems, the back wheels are definately pushing as soon as the fronts start to loose grip, you can feel it.
On the road, the car feels very similar to the way it did it did in 2wd, even on tight corners, wheras before with the old one, there was a feeling of resistance and sometimes even a skipping feel from the rear, as if skidding slightly. I'm a motorcyclist and believe me bikers have a feel for what is going on between the tyres and the road, even in a car.
On tight tickover speed full lock turns in reverse there is the slightest of braking effects, causing revs to drop ever so slightly (its an auto). Forwards, no braking effects have been noticed. However, my understanding of the coupling is and I've done a lot of reading up, that some resistance is inevitable. Particularly with large differences in front and rear axle rotations. How else could the coupling couple if this did not occur.
The inherent stiffness in the coupling should not prove problematic with large differences in axle rotations, when slip is needed, as these should only occur during slow speed turns, such as parking. The slow speeds mean the angular speed of the faster prop is slow enough to overcome the resistance in the coupling, so it slips sufficiently. When 4wd is needed, the difference in angular speed between the front and rear props is what causes the coupling to go stiff and transmit drive, which is what we want.
Problems arise when the stiffness is too great so slip when needed is reduced or absent, like with my failed coupling, OR when there is no stifness, so no 4wd, with some recons apparently, or couplings that have failed in the rarerer mode, ie spin too freely.

This is my theory anyway, please feel free to rubbish it, lol.
regards, Bill

Quote The inherent stiffness in the coupling should not prove problematic with large differences in axle rotations, when slip is needed, as these should only occur during slow speed turns, such as parking
Unfortunately this is not true and is the cause of the problems with this arrangement of accommodating the difference in speed requirements between the front and rear axles.

Landrover have over-geared the drive to the rear axle so that the VCU is responsive, but this requires it to slip even in straight ahead movement. This causes the VCU to load the diff and IRD at all times and when the slip decreases or locks with increased age the crown wheels and pinions in both units are prone to failure. LR did reduce the difference in gearing betwen the axles in about 2001? which has improved things but its still not good if a vehicle cant tolerate having worn tyres on the rear and good ones on the front!

My understanding is that post 2001 the gearing was changed for exactly the reason you give. However that is not my point. Even a new viscous coupling, whether its on a Freelander, Panda4x4, VW synchro 4wd van etc still has an inherent stiffness. With very small differences in propshaft speeds, ie small differences in angle turned in relation to each other, then this small difference should not increase stiffness such that slip cannot occur, i.e slow speed manouvres on tight locks, or even normal steering on normal bends in the road. Extra stiffness and therefore more coupling should only occur with much larger differences in angle of turn of the propshaft, when the front wheels spin or slip say, thus causing the shear effect in the gel to increase stifness and transmit drive.