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2010-2012 Range Rover MkIII / L322
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Discussion Starter #1
Hi Guys,

Apologies if this has been asked befoe but I can't seem to find a definitive answer...

I understand that you can test the VC by jacking up a front wheel and turning it. If the VC is ok, you can turn the wheel although it will be stiff.

Just how stiff should it be? I can turn my wheel but it takes an awful lot of effort (it is VERY stiff to turn). One front wheel seems slightly easier to turn that the other though bizarrely.

I'm just about the replace my front prop as the front UJ is completely knackered (new prop was cheaper than fixing the old one) and RAVE says to access the bolts, simply jack up a front wheel and rotate it to cause the prop to rotate - implying that it ought to be an easy thing to do which prompted me to wonder if perhaps it shouldn't be quite so hard to turn my wheel (which would perhaps also explain why my UJ got damaged in the first place, if you follow me...)

I don't think I should put a new prop on if the VC is suspect as I dont want to trash the diff.

Any thoughts?

Guy
 

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Hopefully Chris won't mind me quoting him but have a look at this:

Jacking up one side of the front axle and ensuring the hand brake is on along with Park if a auto is the correct method, set a torque wrench to 60lbs and rotate wheel forward by placing socket on the wheel nut, you should be able to turn wheel 90 degrees in one minute.
If its failed you'll find it will move barely at first and then lock up say at 45 degrees as the slack is taken up, if so then it failed the test and a new VCU is required.

http://rangeroverworld.blogspot.com/
 

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1995-2002 Range Rover P38A
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As mentioned above.....100 % correct, you'd be amazed at the difference whens its replaced if faulty, be sure to use ATF Dexron 3 as the VCU is lube and temp sensitive
 

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Discussion Starter #4
Thanks guys. I'll give it a whirl.

Had the new prop fitted now so I'd better be sure so I don't risk the diff.

Guy
 

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Not only will you trash the diff it will also damage CV joints along with scrubbing of tyres.
It will again damage the UJs on a new or refurbed prop shaft.
Afer doing a few VCUs I replace diff oils, front diff oils always come out black and contaminated with lots of metal, in other words the damage to the front diff is accelerated by a seized VCU.

Im now testing VCU's as part of any service, way to many front diff oils draining black with metal.
 

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Discussion Starter #6
Ok, finally managed to do the test and it failed, although it does move so it's not completely seized.

Is the VCU a DIY job? Rave doesn't seem to cover it although it does cover the front drive flange and oil seal, both of which apparently require special tools.

If it's DIYable, has anyone come across a walk through for this job? Ashcroft Transmissions have a very general set of instructions, but they're not detailed enough for me to even consider it. Interestingly, their test for the VCU specifies a torque value of 30ft/lbs, not 60! They also reckon that if the car has done more than 100k miles then it might be better to replace the whole transfer box as the chain will have stretched too. Thoughts?

This is one expense I could really do without. Grrr.

Guy
 

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The procedure is in Rave - I looked when I thought I was going to need to do it.
It doesn't look especially complex but then I have not done the job.

Ashcrofts are very very good but don't loose sight of the fact that they sell these things to make a living.
 

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Discussion Starter #8
waveydavey said:
The procedure is in Rave - I looked when I thought I was going to need to do it.
It doesn't look especially complex but then I have not done the job.

Ashcrofts are very very good but don't loose sight of the fact that they sell these things to make a living.
Hmm, it's definitely not in my version of Rave.

Which section is it under? All I've got for the Transfer box, is general description, removal/replacement, and replacement of the driveshaft oil seals. ...

Guy
 

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It's in the Overhaul manaul rather than the main workshop manaul

Gearboxes - transfer boxes - Borg Warner (obviously) - Overhaul - Viscous Coupling Unit
Page 18 of 36
 

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Discussion Starter #10
waveydavey said:
It's in the Overhaul manaul rather than the main workshop manaul

Gearboxes - transfer boxes - Borg Warner (obviously) - Overhaul - Viscous Coupling Unit
Page 18 of 36
Thanks,

I'll have to see if I can find it.

Guy
 

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waveydavey said:
Hopefully Chris won't mind me quoting him but have a look at this:

Jacking up one side of the front axle and ensuring the hand brake is on along with Park if a auto is the correct method, set a torque wrench to 60lbs and rotate wheel forward by placing socket on the wheel nut, you should be able to turn wheel 90 degrees in one minute.
If its failed you'll find it will move barely at first and then lock up say at 45 degrees as the slack is taken up, if so then it failed the test and a new VCU is required.

http://rangeroverworld.blogspot.com/
Putting the hand brake on is a good idea, but keep the transmission, manual or auto, in NEUTRAL or you'll never be able to rotate a wheel. ;)
When in gear (or park), the borg warner diff won't be able to rotate at all.

Greetz,

Filip
 
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