one wheel up test

when doing the one wheel up test does it matter if the car has been driven or not
if so will this effect timed results
cheers

Makes a few seconds difference, so can be tested driven or undriven.

Nodge68 said:

Makes a few seconds difference, so can be tested driven or undriven.

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Thanks for the reply, The reason I ask is I have started to feel an intermittent judder in ist gear and reverse
been under her today and found the front rear diff mount shot and some play in the vcu mounts
while I was at it I did the one wheel up test and got a time of 50 seconds this was after 70mile drive an hour before
the same test 6 months ago I got a time of 35 seconds but this was without driving it
does this sound like the vcu is on its way out
all tyres same least worn on rear
cheers

Nobody (on here at least and possibly anywhere!) knows 100% about VCUs. There's science about how VCUs work and a little science into them failing - but I'm sure even the manufacturers put them together without knowing fully how they expect them to age or be tested etc.

I tested one on a car that hadn't been used for a while. It came back with a time of 3 minutes initially. After repeated tests over (maybe) up to 1/2 an hour, the time came down to about 2 minutes and leveled off.

The 1WUT is just an indication.

The indication on a 2 or 3 minute time is very positive that it is shot.

50 seconds is a 'dodgy' indication cos its not the time you'd say replace it, but not a time you'd be happy with either. With my sensible hat on, my thoughts are to get the diff mount replaced now and use the car and over the next couple of weeks take further 1WUTs - if they go over 50 seconds, get a recon VCU & bearings, if they come in lower, hang it out. If it was my car, and having been through the trauma of a smashed transmission, I'd be doing 1WUTs over the next couple of days and if they are near that 1 minute mark, I'd be on the phone to Bells for a VCU & support bearings. I'd also invest in a TPMS as I'm pretty sure 1 tyre going low took out my transmission.

GrumpyGel said:

50 seconds is a 'dodgy' indication cos its not the time you'd say replace it, but not a time you'd be happy with either

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This is sort of my thinking too, Iv got genuine diff mounts and a pair gkn vcu bearing's in the shed already
been on the phone to bell engineering today they wont have vcu till middle of next week so will use the time to do few more one wheel up tests
probity end up getting recon one for piece of mind
cheers

My VCU is also in that 50 seconds area. I only do local trips bit am well aware that I'm in the times for a potential problem. I've been meaning to refurb my VCU for some time, I just don't have the time to do it. I'm planning on making time this spring however.

Going to do another one wheel up test tomorrow before she moves anywhere, just to see if it makes any
difference to the times.

Just a little up date
iv done another one wheel up test today before she had been driven, to get a better comparison to a test I did 6 months ago (35 seconds) not driven
not good it's gone up 60 seconds and that after recording a time of 50 seconds earlier in the week after driving it.
so iv dropped front prop shaft and ordered recon vcu from bell engineering
just shows how important it is to monitor your vcu
perhaps if I tested it in between might have save my diff mounts
who knows

Could have possibly saved the diff mounts, but they're reasonably cheap and easy to replace. At least you've saved yourself from and expensive bill, so that's a good result

Interesting (alarming!) that the VCU 'turned' that quickly.

freelandy2004 said:

Just a little up date
iv done another one wheel up test today before she had been driven, to get a better comparison to a test I did 6 months ago (35 seconds) not driven
not good it's gone up 60 seconds and that after recording a time of 50 seconds earlier in the week after driving it.
so iv dropped front prop shaft and ordered recon vcu from bell engineering
just shows how important it is to monitor your vcu
perhaps if I tested it in between might have save my diff mounts
who knows

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Are the tyres correct? Mismatched tyres will shorten VCU life.

Nodge68 said:

Are the tyres correct? Mismatched tyres will shorten VCU life.

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They have been for the last 2 and 1/2 years (35000 miles) iv had her,
new tyres bought in pairs, new one's always on rear also I do keep close eye on tyre pressures
she got 126,000 miles on her now, iv got no paper work to say when or if the vcu has ever been changed before.

freelandy2004 said:

They have been for the last 2 and 1/2 years (35000 miles) iv had her,
new tyres bought in pairs, new one's always on rear also I do keep close eye on tyre pressures
she got 126,000 miles on her now, iv got no paper work to say when or if the vcu has ever been changed before.

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At that mileage, I'd expect the VCU to be past its best. Mine is timing at 45 seconds with 123K on it now. I'll be refurbishing it in next few months I think.

another up date
iv had a recon vcu plus my support bearing's and dif mounts fitted at bell engineering last night
great service all done in just over an hour (big thank you to them)
plus the added bonus I got out to play in some proper snow on the way back
and she performed beautifully
will do another one wheel up test when the weather clears

I wonder if the really cold weather makes a difference to the test. I would imagine the fluid is thicker when the temp is below freezing.

Col

Colthebrummie said:

I wonder if the really cold weather makes a difference to the test. I would imagine the fluid is thicker when the temp is below freezing.

Col

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possible I have no idea when I tested mine last week it was about 5 or 6 degrees

Colthebrummie said:

I wonder if the really cold weather makes a difference to the test. I would imagine the fluid is thicker when the temp is below freezing.

Col

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Mine was 55 seconds when the VCU was at 15°C. 10K miles later it timed a sorter time of 45 seconds when the VCU was at a temperature of 0°C. I don't know for definite that temperature has a bearing on the time, but it seem strange that the VCU has freed up with more mileage on it.

Nodge68 said:

Mine was 55 seconds when the VCU was at 15°C. 10K miles later it timed a sorter time of 45 seconds when the VCU was at a temperature of 0°C. I don't know for definite that temperature has a bearing on the time, but it seem strange that the VCU has freed up with more mileage on it.

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bell engineering don't believe in our test as such they say other thing's can influence the results
but I now think if you keep all things the same when testing (same bar ,same weight, test done before driven ect)
all we can do is monitor it
will post back with result from recon unit

freelandy2004 said:

bell engineering don't believe in our test as such they say other thing's can influence the results
but I now think if you keep all things the same when testing (same bar ,same weight, test done before driven ect)
all we can do is monitor it
will post back with result from recon unit

Click to expand...

Bell Engineering were an active partner in the OWUT when it was first devised. They later started to rubbish the OWUT as invalid, even though there own VCU test uses the same weight over time principle.

Presumably they decided that people could test there own VCU, finding it OK and not buy a reconditioned unit from them.

Here's the original OWUT thread where Austen from Bell helped with its development.

https://www.landyzone.co.uk/land-rover/an-open-letter-to-austen.148283/page-2#post-1469798

This thread also has some good information and numbers in connection with the OWUT. Just ignore all posts by banned member JoeH as he was just kicking the hornets nest, and had no technical knowledge of the VCU.
https://www.landyzone.co.uk/land-rover/owut-bells-test-on-youtube-compared.306902/