VCU Torque test results

Nodge68 said:

Did another turnip test today.
After 20 miles with speeds ranging from 40 to 70.
VCU measured 37°C
Ambient temperature was 9°C
Now for something curious!
The front propshaft measured 55°C at the UJ where it's splined to the VCU.
The rear propshaft measured 51°C at its UJ splined to the VCU.
So being that the VCU is mechanically connected to the propshafts, there must be a heating effect on the VCU!!

Click to expand...

yu would expect the UJ's to generate heat, as they are continuously working.

The Mad Hat Man said:

yu would expect the UJ's to generate heat, as they are continuously working.

Click to expand...

The whole shaft is hot not just the joint! It can only be warmed heat from the engine or from the exhaust?

No 32mm socket so had to improvise with a few lumps of wood and cable ties.

1 meter pole, 5 litre bottle of water (which I assume is 5 kilos).
45 degrees = around 28 seconds.

Longer than I was expecting but encouraging going by some of the results on here!

Spacemonkey... said:

If you can, can you do a test after a nice 15-20 mile+ journey while it is warmed up fully? Ta!!

Click to expand...

Ok will do.. next time I get back from a journey and the wife isn't around (to moan about my misuse of time) then I will do so

Hmmm... did the test tonight on my recently acquired 2002 TD4 with 132k - using 1.2M bar and 5kg weight - 55 seconds. Guess I need a new one...

It's possible some of the high results we're seeing are down to tight rear diffs. could also be rear brakes catching. Any suspect vcu's with high times for the one wheel up test should be removed and bench tested as follows. Bench testing tests just the vcu on it's own without any possible transmission tightness interfering with the results.

With the props still attached to the vcu, clamp 1 side of the vcu stationary (I put a long screw driver through the uj on one side of the vcu and held the screw driver stationary with a work mate) and put a 2nd long screw driver through the other uj on the other side of the vcu. Put a weight on the end of the 2nd long screw driver and time it to see how long it takes to turn 45 degrees to the horizontal.

Using a weight of 5.2kg and length 34cm = 17Nm = 67 seconds
Using a weight of 10.2kg and length 38cm = 38Nm = 23 seconds

As the Nm force is lower (due to a shorter distance between the weight hanging oft the screw driver, to pivot point) the times will be higher, when compared to the one wheel up test.

Not everyone has a 32mm socket to perform the one wheel up test using the 32mm nut in the centre of the wheel. This I can appreciate. However, some have tried to use the normal wheel nuts (5 of them) used to hold the wheel on. Please don't do this as you risk snapping the nut off it's stud. This has happened to a forum member recently so I'm putting this here as a warning to all.

The longer the bar and the greater the weight, the more torque (stress) you put on the nut. The centre 32mm nut can take it as it's fekin tight and strong. The normal wheel nuts (5 of them) can't. The typical weights and bars we're using aren't too bad, as they're putting a similar amount of pressure on the nut that you would do to tighten it yourself. Yes it can probably take a lot more torque but there's no point in risking this or trying to find a weak point. Safety takes preference.

I would prefer peeps didn't use the wheel nut (5 of them) for the one wheel up test. Using longer bars or higher weights increases the chances of the wheel nut snapping off.

The cost of a 32mm socket is a small cost compared to the prospective risk & cost of not checking the VCU.

As in all things on this forum. It is at your risk.

The Mad Hat Man said:

The cost of a 32mm socket is a small cost compared to the prospective risk & cost of not checking the VCU.

As in all things on this forum. It is at your risk.

Click to expand...

Well said.

1.3m bar 8ltr water (about 8kg)

vcu was cold tho forgot about warming it up 43 seconds

2000 TD4 75,000 miles .

Cold VCU 9 degrees C ( would like to repeat in summer when double that temp)
1.2 m bar with 5kg @45 degrees to level with sill took 38 seconds .
6kg took 29 seconds .

1998 FL1 1.8 petrol 184000km [ 114000mls] - 1.2m bar VCU 'cold' no run done.
1st weight 3.2kg = virtually no movement from 45º, veerry slow to move at all.
2nd weight 4.2kg = slow movement - 10.54mins to horizontal from 45º
3rd weight 5.2 kg = a bit faster = 9.44 mins to horizontal from 45º

I know my VCU is shot as there is a lot of wind up in reverse and forwards on lock.

FL TD4 2002 70k miles
Reading all the posts has made me concerned. Rear right wheel jacked up, I can just about turn the wheel using hands on outer diameter of tyre. I marked two white marks on front and rear prop where they could be seen prior to the gurning!! After the "red sock" tucked back in my rear end, viewing the two marks they have split alignment. My main concern is having only had the thing 5 months it won't roll down a medium grade incline (in neutral) unless steering is straight ahead , if you apply steering turn whilst she's rolling it comes to a stop with a brake type rubbing sound from the VCU. Anyone else tried this?? Is this the norm?
Cheers

I will have to do this test Friday before I pay for the FL I have just purchased, I did ask if everything was working and was assured it is we shall now see, brilliant thread, I am loving this forum so far cheers Arctic2

Freelander 2006 Td4 93,500 miles
VCU Test

Ambient Temperature 15 degrees C
Car had been stationary for >48 hours

Length of pole 1.2m
Weight = 5 kilos
The following timings are for a traverse from 45 degrees to 0 degrees from the horizontal

Lap 8 000:00:00:59:055
Lap 7 000:00:00:46:774
Lap 6 000:00:00:49:604
Lap 5 000:00:00:55:655
Lap 4 000:00:00:35:816
Lap 3 000:00:01:03:174
Lap 2 000:00:00:49:667
Lap 1 000:00:00:43:500

Average: 000:00:00:50:406

Lap three is ignored as the socket nearly came off and lap 4 is also ignored as it seems too short (in fact ignoring both makes little difference anyway) so :

1 59.06
2 46.77
3 49.60
4 55.64
5 49.67
6 43.50
Total 304.24
Average 50.71


So for a 1.2 m pole and a 5kg weight at 15 degrees C time taken is roughly 51 seconds.


Looking at "Hippo's" graph gives 35.5 seconds however the ambient temp was 23 degrees C.


So I guess this isn't too bad a result just not sure how much difference the temp makes? any comments from those with more experience? I already have a new GKN VCU (from island 4x4) so I will be replacing it anyway but thought I the results may be useful plus I wanted to know if I needed to take the prop off before I could get around to actually changing the VCU.


Many thanks to all those (Specially Hippo and MHM) who have posted on this site and given their time and experience so lurkers like me can take a shorter route.

Good response. Personally, I would think almost a minute is too slow. Be interesting to see what the new one gives.

busa1300 said:

FL TD4 2002 70k miles
Reading all the posts has made me concerned. Rear right wheel jacked up, I can just about turn the wheel using hands on outer diameter of tyre. I marked two white marks on front and rear prop where they could be seen prior to the gurning!! After the "red sock" tucked back in my rear end, viewing the two marks they have split alignment. My main concern is having only had the thing 5 months it won't roll down a medium grade incline (in neutral) unless steering is straight ahead , if you apply steering turn whilst she's rolling it comes to a stop with a brake type rubbing sound from the VCU. Anyone else tried this?? Is this the norm?
Cheers

Click to expand...

Do the test properly. What have you got to loose?

2006 td4 with 52,000 miles
A 5kilo weight at 1m took an average time of 54 seconds after 10 attempts.

Dave

Compared with my "old" 120k Freelander which took about 35 secs my "new" 55 reg 80k Freelander took 2 minutes 20 sec with 5kg at 1.1m ( mop handle on T bar!) , booger !

As usual still drives ok , does tickover full lock turns forwards an backwards .

So started looking around for VCUs and maybe an IRD locally and now seem to have bought another whole Freelander..........

And the new bought for parts but "enjoying driving it too much to break up" 2000 reg 1.8 with 103k miles takes 1 minute 30 sec with 5L at 1.1 M