VCU Torque test results

[The Mad Hat Man]

yep. carefully drilled 2x 7mm pilot holes about 8mm deep to break through side faces, 10mm in from edge of outer casing of vcu at opposite ends and sides of it, tapped holes m8, drilled 3mm pilot hole through an old m8x16 bolt, cut head off bolt to act as a pipe connection, heated viscous coupling with hair dryer for about 15 minutes, connected line to m8 bolt screwed into vcu and onto compressor. blew treacle out of coupling, then flushed with thin oil.
force filled with gear oil. fitted m8 short bolt with dowty washer to seal.

and what exactly did that achieve?

 

[Freelaner]

It's not gear oil it's a specially prepared viscous fluid.
You might as well have taken the prop off cos that'll be doing feck all!

 

[Singvogel]

I refuse to believe that that will work.

Try it on wet grass,full throttle and report back.

I reckon it's now 2-wheel drive.

 

[jamesmartin]

and what exactly did that achieve?

an unexchangeable unit

 

[Hippo]

yep. carefully drilled 2x 7mm pilot holes about 8mm deep to break through side faces, 10mm in from edge of outer casing of vcu at opposite ends and sides of it, tapped holes m8, drilled 3mm pilot hole through an old m8x16 bolt, cut head off bolt to act as a pipe connection, heated viscous coupling with hair dryer for about 15 minutes, connected line to m8 bolt screwed into vcu and onto compressor. blew treacle out of coupling, then flushed with thin oil.
force filled with gear oil. fitted m8 short bolt with dowty washer to seal.

Can you try the one wheel up test as shown in me video below and let us know the result? Thanks.

 

[tariq]

i did the VCU TEST ( 1 wheel off of the ground -front) but when i didt it i couldnt spin the wheel round, it just would move!! did i do the test wrong or is the VCU had it??? any help would b mucho apprieciated!
thanx

 

[jamesmartin]

vcu has had it if wheel wouldnt turn stiffly but turn

 

[tariq]

vcu has had it if wheel wouldnt turn stiffly but turn

SO U THINK ITS REALLY HAD IT?? when i did one wheel test i could move wheel a few cm, then nothing, i dodnt want to try and force it round as i was lead to believe that it should move round albeit slowly without a lot of force, that is right yeah?

 

[jamesmartin]

SO U THINK ITS REALLY HAD IT?? when i did one wheel test i could move wheel a few cm, then nothing, i dodnt want to try and force it round as i was lead to believe that it should move round albeit slowly without a lot of force, that is right yeah?

no viscous couplings are stiff the faster more power you use to turn them the stiffer they get ,if it wont turn its siezed

 

[Hippo]

It does sound like the vcu is past it's best. To be sure you could try the test on a rear wheel, with the hand brake off. If your concered your hand brake may still be applied, lift both rear wheels and turn 1. It will turn the other easily. Don't lift both during the vcu test.

Also can you time the test you perform and give us the time, weight and distance of weight to pivot point?

 

[The Mad Hat Man]

woteffa happened to this thread being for results, so we could colate some meaningful figures?

 

[Kizzeh]

i did the VCU TEST ( 1 wheel off of the ground -front) but when i didt it i couldnt spin the wheel round, it just would move!! did i do the test wrong or is the VCU had it??? any help would b mucho apprieciated!
thanx

I could be wrong but i should think its because you lifted your front off the ground. This is the side of the gearbox and if you applied too much pressure all you would do is rock the car off the jack. Try the rear.

Only just read the thead. will try the test tomorrow if i remember

 

[Kizzeh]

i did the VCU TEST ( 1 wheel off of the ground -front) but when i didt it i couldnt spin the wheel round, it just would move!! did i do the test wrong or is the VCU had it??? any help would b mucho apprieciated!
thanx

I could be wrong but i should think its because you lifted your front off the ground. This is the side of the gearbox and if you applied too much pressure all you would do is rock the car off the jack. Try the rear.

Only just read the thead. will try the test tomorrow if i remember

 

[Kizzeh]

shows how slow my internet is. double post with 7 mins inbetween

 

[andyfreelandy]

I've just sold my V6 and bought a TD4 2002. The TD4 is in great condition but grinds on tight lock so have read all of teh thread with interest. What I can't find are the results !!!

In an effort to support this forum I have carried out the rear wheel in the air torque test on the V6 (which was seemingly fine) and the TD4 which is grinding when on tight lock and is off for a new VCU on Wednesday at Bell Engineering.

In order to try to get some 'measurement' of the force required to turn the wheel I used a torque wrench on the centre nut and adjusted it until I could 'just' turn the wheel with a steady force and without the torque wrench 'clicking'. I observed around 60 lb ft for the V6 and around 80 lb ft for the TD4. Will let you know what the replacement unit registers. I know that this is not an exact science, but an 'on car' measurement is long overdue!!! For the record the V6 has done 70k and the Td4 80k. Cheers and any more figures welcomed.

 

[Hippo]

I've just sold my V6 and bought a TD4 2002. The TD4 is in great condition but grinds on tight lock so have read all of teh thread with interest. What I can't find are the results !!!

In an effort to support this forum I have carried out the rear wheel in the air torque test on the V6 (which was seemingly fine) and the TD4 which is grinding when on tight lock and is off for a new VCU on Wednesday at Bell Engineering.

In order to try to get some 'measurement' of the force required to turn the wheel I used a torque wrench on the centre nut and adjusted it until I could 'just' turn the wheel with a steady force and without the torque wrench 'clicking'. I observed around 60 lb ft for the V6 and around 80 lb ft for the TD4. Will let you know what the replacement unit registers. I know that this is not an exact science, but an 'on car' measurement is long overdue!!! For the record the V6 has done 70k and the Td4 80k. Cheers and any more figures welcomed.

Your results won't give an easy true comparison. You need a special 2x bar type torque wrench to do the test with a torque wrench. You need to do the "one wheel up test" as below, which uses gravity as a datum:

http://www.landyzone.co.uk/lz/1628997-post6.html

Reason why http://www.landyzone.co.uk/lz/1470266-post35.html

Video below in me signature.

 

[andyfreelandy]

O.K - got the recon unit fitted and noise on full lock disappeared (although a front diff mount to replace as noted as faulty).

Done the torque wrench test on this one this morning. It registers 35 lb ft.

Now - I acknowledge all the comments about this not being accurate etc, but what we need is a 'go-nogo' test that can be done with the VCU fitted to the car with tools that most people will have.

My experience has shown that if you use a standard torque wrench applied to the centre nut on a rear wheel in the air and;

1) set wrench to around 30 lb ft.
2) apply just enough force to get wheel to move slowly and adjust torque wrench (upwards) just enough to prevent the torque setting click occuring then take the reading when the wheel turns smoothly.

Ignoring the fact that the V6 has different axle ratios (it is an order of magnitude difference so I personally think we can ignore these). A reading of 30 - 60 lb ft shows a 'fair' VCU and a reading over 60 shows a VCU that may require and warrant the effort of a professional check.

This simple, measured test may save us all a load of expense with secondary damage.

What say others???

Cheers, Andrew

 

[jamesmartin]

O.K - got the recon unit fitted and noise on full lock disappeared (although a front diff mount to replace as noted as faulty).

Done the torque wrench test on this one this morning. It registers 35 lb ft.

Now - I acknowledge all the comments about this not being accurate etc, but what we need is a 'go-nogo' test that can be done with the VCU fitted to the car with tools that most people will have.

My experience has shown that if you use a standard torque wrench applied to the centre nut on a rear wheel in the air and;

1) set wrench to around 30 lb ft.
2) apply just enough force to get wheel to move slowly and adjust torque wrench (upwards) just enough to prevent the torque setting click occuring then take the reading when the wheel turns smoothly.

Ignoring the fact that the V6 has different axle ratios (it is an order of magnitude difference so I personally think we can ignore these). A reading of 30 - 60 lb ft shows a 'fair' VCU and a reading over 60 shows a VCU that may require and warrant the effort of a professional check.

This simple, measured test may save us all a load of expense with secondary damage.

What say others???

Cheers, Andrew

nearer the mark and done regulary shows any stiifening and gives time to arrange replacement ,

 

[The Mad Hat Man]

sounds a good simple system, but the usual method involves a known length pole, a known weight and a known angle of displacement (normally 2 Oclock-5Oclock) and the time taken is measured. using a torque wrench has been thought of before, but I think it was discounted. I would like to see Bells comments on this.....


results are here

 

[andyfreelandy]

Thanks for link to results.

Not sure what the 'Force' column is, but interestingly a new one at 5Kgm is around 36lbft and a 77k miles one at 9.6Kgm is around 70lbft - this ties in with my results precisely. maybe it is the same test recorded for completeness?
Andrew