How to recondition a VCU yourself.

ok stops working, finally gave up the ghost whatever.

re your comment I have had vehicle from new in 2000, ALWAYS kept it with four identical tyres usually replace the fronts only in between a full change of 4.

terrier989 said:

ok stops working, finally gave up the ghost whatever.

re your comment I have had vehicle from new in 2000, ALWAYS kept it with four identical tyres usually replace the fronts only in between a full change of 4.

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That would explain the early and sudden demise of your VCU/IRD. It's good to keep all tyres identical. However the new tyres MUST always be fitted to the rear. The half worn rears, being moved to the front. If the fronts are replaced, the VCU tries to equalise the rotation of the propshafts. This puts huge strain on the IRD and rear diff, causing one to fail eventually.

I was always told that you should never put the rears on the front as they can have the threepenny bit profile and cause vibration, but in light of what you say i will try that next time.

when you say early demise it had done 110 k and I did read somewhere LR recommend 70K.

terrier989 said:

I was always told that you should never put the rears on the front as they can have the threepenny bit profile and cause vibration, but in light of what you say i will try that next time.

when you say early demise it had done 110 k and I did read somewhere LR recommend 70K.

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LR state in the owner's handbook that tyres should be replaced in fours. However it is acceptable to replace just two tyres at a time, providing the new tyres are identical to those on the vehicle and new tyres are fitted to the rear. The rear tyres being replicated to the front, so the front/ bias remains with acceptable limits.

LR don't specify a change interval for the VCU. However VCU reconditioners may have suggested 70K as an acceptable change interval.
110K miles is well under the full service life of an IRD, providing tyres are maintained as per LRs instructions. My own TD4 currently has 123K miles on is with no IRD or VCU problems. I know the tyres have been maintained using the correct procedure, which would account for the current condition.

I've seen 70k mentioned too but I don't believe LR ever made that official. As for Nodges comment on early demise, most of the cars on this forum have a lot more than 110k miles with original drive train and VCU. You were either unlucky as 99% (made up figure but probably close to the truth) of owners and Tyre shops will replace fronts only. Or you drove for an extended time with different tyre pressures which puts extra strain on everything.

Edit, Nodge beat me to it.

Alibro said:

I've seen 70k mentioned too but I don't believe LR ever made that official.

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mee neeva.

Nodge68 said:

LR state in the owner's handbook that tyres should be replaced in fours. However it is acceptable to replace just two tyres at a time, providing the new tyres are identical to those on the vehicle and new tyres are fitted to the rear. The rear tyres being replicated to the front, so the front/ bias remains with acceptable limits.

LR don't specify a change interval for the VCU. However VCU reconditioners may have suggested 70K as an acceptable change interval.
110K miles is well under the full service life of an IRD, providing tyres are maintained as per LRs instructions. My own TD4 currently has 123K miles on is with no IRD or VCU problems. I know the tyres have been maintained using the correct procedure, which would account for the current condition.

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Thanks both
just checked the tech manual on rave cd but it wasn't in there, it was a LR spec sheet I found on the web and it advised 70k , anyway happy with what you are telling me.

in the tech spec section it tells you if it is being towed with two wheels up off road the relevant part of prop shaft must be disconnected to prevent the vcu turning, but interestingly it also says same applies to a two wheel rolling road, never seen it done on an MOT presume the time it is on there is acceptably short.

cheers

terrier

terrier989 said:

Thanks both
just checked the tech manual on rave cd but it wasn't in there, it was a LR spec sheet I found on the web and it advised 70k , anyway happy with what you are telling me.

in the tech spec section it tells you if it is being towed with two wheels up off road the relevant part of prop shaft must be disconnected to prevent the vcu turning, but interestingly it also says same applies to a two wheel rolling road, never seen it done on an MOT presume the time it is on there is acceptably short.

cheers

terrier

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I asked an MOT man about this and he said they set the rolling road to rotate the wheels in opposite directions if the propshaft is fitted.

Alibro said:

I asked an MOT man about this and he said they set the rolling road to rotate the wheels in opposite directions if the propshaft is fitted.

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Not all do that Ali. I discovered an MOT test centre near my simply run the rollers on the fronts then the rears. The Fl tried to climb out the rollers as the test was carried out. I suspect that it doesn't do any damage, but will give incorrect brake readings.

Nodge68 said:

Not all do that Ali. I discovered an MOT test centre near my simply run the rollers on the fronts then the rears. The Fl tried to climb out the rollers as the test was carried out. I suspect that it doesn't do any damage, but will give incorrect brake readings.

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The MOT centres here in NI are extremely professional as they are all owned and run by the council. Not to say they don't make mistakes but never had that problem.

Alibro said:

I asked an MOT man about this and he said they set the rolling road to rotate the wheels in opposite directions if the propshaft is fitted.

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sorry lost me there, are you saying two wheel rolling road and you set the sides to operate opposite directions?

terrier989 said:

sorry lost me there, are you saying two wheel rolling road and you set the sides to operate opposite directions?

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Yes. There's a free turning diff between sides. So by spinning the rollers in opposite directions, only the brakes are coming into play. If an axle, front or rear is spun, then the VCU will cause drag because it'll try to pass the rotation to the other axle which isn't on the rollers. The Freelander will try to climb out the rollers when this is done. It'll not do damage as it's designed to pass torque, but it will make the brake measurements incorrect.

ta, will ask my MOT guy

Wot Nodge said.

will ask him does he do it and if not why not

LR have never advised to automatically change the vcu every 70k miles. They have never listed 70k miles or any other value of it's useable life. It's all a myth made up by vcu re-conners giving their "opinion" based on their "judgement". Mine failed about 35k miles...

Hi all,

sorry for delay, offside front drive shaft changed got a euro gkn recon as advised (see I do listen), vcu checked 32s, 4 times on the run, done abt 80mls since all seems well at the mo, fingers crossed.

re rolling road yes he does do as ppl said just I had not noticed.

thank to everyone for their help, hope you all had a good xmas and enjoy a happy and prosperous new year.

terrier

A reputable VCU recon agent recently advised me what is the obvious when you have the experience of having owned one of these vehicles, and read up much on here. It's all about the tyres! Prudent maintenance and sensible changes. Keep them all the same, keep the pressures the same. replace all four together if possible. If you can't replace them all together, stick the new ones on the back. It is said over and and over again.

There is no advisory life for the VCU. Keep up the maintenance, and do the test regularly for peace of mind.

I agree: there is no mandatory change point for the VCU as a consumable. But from an enthusiast's persepective, 70k miles seems like a sensible mileage at which you start undertaking regular OWU tests on an annual basis

rob_bell said:

I agree: there is no mandatory change point for the VCU as a consumable. But from an enthusiast's persepective, 70k miles seems like a sensible mileage at which you start undertaking regular OWU tests on an annual basis

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No. This is wrong. It needs to be done regular, not after a certain amount of miles.