If it possible for the wheel up test to pass but still the vcu knackered? I removed the propshaft for now until I change bearings which are on order and now the car pulls way better. I remember I used to have something holding back like breaking but not very noticeable. I guess safest thing to do is replace it... bit of an unwanted expense at least not until I sort the engine (turbo, injectors, etc)
Hippo
Lord Hippo
Yes but its rare the OWUT won't detect failure or starting to fail IF the test is done right.
The one wheel up test OWUT is a static test which it the best representation we have. There is also the Turnip Test which measures VCU heat which is a side effect of the VCU resisting stress applied across it when driving. Too cool and its not slipping much. Too hot is slipping too much. Naturally that is all off set by the condition of yer tires. A good VCU will be put under more stress if you have mismatched tires and fail sooner if not corrected. Those with the deepest tread go on the rear. Tires should be the same make, model, size and pressure
When taking the VCU off the car it will feel looser to drive. The steering will feel lighter anorl. Often owners think the VCU is faulty by default because of this. Its not. Its the way its designed to work and feel. Also when fitting a recon VCU which has been reconditioned in such a way as to resist less, it can also make you think the original VCU was faulty becare the recon one feels like it 'drags' less.
When removing the VCU its easier to remove it and the prop shafts in one go. Especially if the bolts on the VCU haven't been removed for some time. Removal is a modification so yer will need to advise yer insurance company.
Alibro
Well-Known Member
Take it onto wet grass and try to spin the wheels. If you can easily then there is something wrong.
Hippo
Lord Hippo
What weight and time?
Yer probably got a lose recon. Do the above wheel spin test to see if the vcu activates.
A month back I was getting my Freelander MOT'd and it failed on a split gaitor on the driveshaft, so they removed the driveshaft for the MOT (they consulted me first and I said yep, take it off then). I have been having great 'fun' disassembling the driveshaft from the VCU, which required splitting a UJ . Anyway to cut a long story short my old owut test was running nearly 2 minutes about a year ago, so I figure the VCU is toast. I seems locked solid, I mean I was expecting to be able to make it move a bit with some long sticks. So I guess the thing to do is send it to Bell for a rebuild. Now my question is, being a wimpy woman, I can barely lift the drive shaft as one unit, but is it possible to fit it in stages, maybe VCU first, so it slides on bolts, then fit the front and then rear? or do I give up and just give it to a garage to fit. I don't want to give it to the garage to fit...-Hazel
Nodge68
Well-Known Member
That's the sensible thing to do, as 2 minutes is well past the maximum 1 minute recommended OWUT test result.
I is possible to split it up for fitting in sections. However it's actually more work than it would seem. The easiest way is to support the VCU on blocks or a trolley jack, so it's about 6" lower than it's mounts. Then fit the front and rear propshaft flanges into place, fixing them with a couple of bolts at each end. Then lift the VCU up to it's normal position, so it's mount bolts can be fitted. Completely secure the ends to the IRD/ rear diff flanges, then align the VCU to the centre line of the vehicle, making sure the bearings are exactly 90° to the VCU shafts. That's it, it's not that difficult or strenuous, as long as you are methodical.
GrumpyGel
Well-Known Member
I have not removed/fitted a prop shaft in its separate pieces, so I can't say for sure, but I would agree with Nodge that it would be far simpler to install it in combined - using blocks/jack to lift and support the pieces. I would probably fit the VCU first though and then the 2 ends to the IRD & diff.
The link above from Hippo has lots of useful into in there. You may get a bit lost in there though finding the bits that are useful. For example, you may contemplate the bits about removing the support bearings from the VCU & fitting them - however, if you are getting a recon VCU from Bells, it is best to get new support bearings as well and Bells will supply them prefitted - you can also send your unit back with the bearings still attached.
It is a shame that you didn't post this before you split the UJs to separate the props from the VCU. There is info in that link to show you how to do it. I've used that method and it takes some blind faith and heavy hitting with a hammer, but it works Here's a video I and others have used as advice for doing the job.
Good luck, you sound like you are more than capable of achieving what you need to.
The link above from Hippo has lots of useful into in there. You may get a bit lost in there though finding the bits that are useful. For example, you may contemplate the bits about removing the support bearings from the VCU & fitting them - however, if you are getting a recon VCU from Bells, it is best to get new support bearings as well and Bells will supply them prefitted - you can also send your unit back with the bearings still attached.
It is a shame that you didn't post this before you split the UJs to separate the props from the VCU. There is info in that link to show you how to do it. I've used that method and it takes some blind faith and heavy hitting with a hammer, but it works
Here's a video I and others have used as advice for doing the job.Good luck, you sound like you are more than capable of achieving what you need to.
Alibro
Well-Known Member
I have not removed/fitted a prop shaft in its separate pieces, so I can't say for sure, but I would agree with Nodge that it would be far simpler to install it in combined - using blocks/jack to lift and support the pieces. I would probably fit the VCU first though and then the 2 ends to the IRD & diff.
The link above from Hippo has lots of useful into in there. You may get a bit lost in there though finding the bits that are useful. For example, you may contemplate the bits about removing the support bearings from the VCU & fitting them - however, if you are getting a recon VCU from Bells, it is best to get new support bearings as well and Bells will supply them prefitted - you can also send your unit back with the bearings still attached.
It is a shame that you didn't post this before you split the UJs to separate the props from the VCU. There is info in that link to show you how to do it. I've used that method and it takes some blind faith and heavy hitting with a hammer, but it works
Good luck, you sound like you are more than capable of achieving what you need to.
This is a great video but there are a couple of things to note.
1. Look at how slim the chisel is and how gently it gets fatter. This will make the job much easier than with a common chisel like mine which is mostly straight with only the last inch or so reducing to a point.
2, The coupling in the video came apart VERY easily. in most cases one of them will be easy but the other will be a complete barsteward requiring a lot more violence (and a much bigger hammer) than shown. Especially if you don't have a suitable shaped chisel.
Right! IRD back together so I quickly tried the one-wheel-up test before I took it for a drive. With 5kg at 1.2m it took 50 seconds to do the 45 degrees in about 10 degrees ambient temperature. I'd be grateful for thoughts on whether that's acceptable or not,please.
Thanks for that. I found a YouTube video where the guy got 35.5 seconds for the same weight and moment arm length in 23 degrees of ambient temperature. (Not sure how much temperature affects them and whether it is reasonable to expect significantly longer in lower temperatures)? I shall monitor it over the coming months. My sister doesn't know whether it was a reconditioned one or not, but looking at the prices of new GKN ones, (and given that she and her husband never actually lavished any money on the poor thing if they could absolutely help it!) I'm guessing it's a reconditioned one. It's only done about 12,000 miles though.
Ta, that's useful to know. It was a fairly conservative 50 seconds, I reckon if I used a proper stopwatch and took a bit of time setting up my 45 degree line and a horizontal, I might get a second or so off that.
GrumpyGel
Well-Known Member
I don't know what mine was like when my IRD blew, I hadn't tested it before, but I tested it after the event (and i think it was a tyre that did it) but what ever condition it was in before, after going through that, then dragging the front prop round for a year or 2 in 2WD it was solid as
When I picked up my parts car, the transmission on that was sound and oil in IRD looked good. I believe it had been standing for a while before I got it and I never drove it. The first 1WUT I did on it returned about 3 minutes. It gradually came down as I repeated the test, but only to about 2 minutes. I wouldn't use it, but it didn't look as though it had done any harm to the transmission.
Geodark
Active Member
Just fitted a recon vcu after having the prop off for the last 6 months, and reverse feels quite tight when on full lock - can't remember what it felt like before to be honest, guess I am just a bit concerned in case this VCU is worse than the last one. I only replaced it as the carrier bearings where shot and the UJs a bit iffy so I thought I would do it all in one go. Replaced the IRD oil while I was on at it, old stuff the looked fine. Just hope I am being paranoid haha. I think I will do the OWU at the weekend to see what the time is like. Bought the bloody VCU 6 months ago so will be out of warranty now - got it off ebay from a seller with good feedback so hoping its just me.
Hippo
Lord Hippo
Test yer vcu with the One Wheel Up Test.
