Viscous Coupling

[BO00YA]

Hey guys,

I am pretty new to the forum. I have a 2000 XEDi Freelander and i am suspicious of my Freelander Viscous Coupling. I have done the one wheel jacked up method and unfortunately it doesn't turn. So i suspect it is seized.

With some research i have found that they have brought out a revised VCU which came out in the later models.

Mine looks like this
http://imagenes.solostocks.com/z2_4178765/ird-transfer-y-vcu-viscous-coopling-diferencial-para-freelander-de-land-rover.jpg

Is this the from the later models?
https://www.aulro.com/afvb/images/imported/2009/08/1826.jpg

I've been told by a Land Rover garage that the single cylinder VCU (Second picture) is from a V6 and might not fit my 1.8L.

So i don't know if it is the revised VCU or just from a V6.

Any information would be greatly appreciated.

Thanks in advance.
Ben

[BO00YA]

Ok. Not convinced with my first test. I did the dot method. I went around the block and once i got home i checked the aligned dots on the shafts and they are no longer aligned which would indicate the VCU is not seized?...Now i am confused...:mad:

[mike 90 RR]

Ok. Not convinced with my first test.

Jack up 1 REAR wheel .... Put a wheel brace on a wheel nut and then stand on it ...should turn the wheel if not seized
... (It will be hard to turn the wheel)

Mike
:)

[BO00YA]

Jack up 1 REAR wheel .... Put a wheel brace on a wheel nut and then stand on it ...should turn the wheel if not seized
... (It will be hard to turn the wheel)

Mike
:)

Hey Mike,

Yeh that's what i did. No good.

[mike 90 RR]

Yeh that's what i did. No good.

With the hand brake off???

Mike
:)

[BO00YA]

With the hand brake off???

Mike
:)

Hey Mike,

Yeh handbrake off and in first gear. I went off Garrycol's thread.

[mike 90 RR]

Yeh handbrake off and in first gear.

Fair enough ..... ;)



https://www.aulro.com/afvb/images/imported/2009/08/1826.jpg


Another way to do it ....
Tailshaft in the left hand side of the photo ... You can see a space at the "uni joint" that you can slide a bar through ....


1: To turn the Tailshaft between the rear diff & VCU
Both rear wheels off ground / 1st gear / give it a 2 arm + leg pull on the bar //// CHOCK THE FRONT WHEELS /// USE AXLE STANDS

2: To turn the Tailshaft between the engine & VCU
Put the rear wheels on the ground .... hand brake on ... gearbox in neutral (not in park or in gear) give it a 2 arm + leg pull on the bar




I went off Garrycol's thread.

Send him a PM

Mike
;)

[BO00YA]

Hey Mike,

Thanks, I'll give it a go. I need to invest in some stands first.

Thanks heaps for your help mate.

[101RRS]

The correct VCU is the first pic - I have no idea what the second pic is of. As I PMd - the VCU comprises the VCU and a large vibration damper.

Garry

[101RRS]

Oh - if the wheel did not move with the test but the dots have moved - then one of the tests was not done correctly.

In the test where the wheel is lifted off the ground - the wheel will be difficult to turn but if the VCU is OK it will turn with steady pressure - pushing at it in an ad hoc manner will do nothing - steady pressure is required.

Garry

[BO00YA]

Hey Garry,

I did the test exactly how you described in your video. I gave as much steady pressure as i could. If i can take wheel nuts off, i'm pretty sure i would be able to turn the VCU if it wasn't seized. I'm just very confused at the moment.

If the dot test worked, would that indicate that the VCU is fine?

[mike 90 RR]

Hi BO00YA .... On a side track .... What symptoms have you been experiencing that lead up to all this in the first place??

Mike
:)

[101RRS]

Hey Garry,

I did the test exactly how you described in your video. I gave as much steady pressure as i could. If i can take wheel nuts off, i'm pretty sure i would be able to turn the VCU if it wasn't seized. I'm just very confused at the moment.

If the dot test worked, would that indicate that the VCU is fine?

I can understand the confusion. My VCU is very tight and requires considerable effort to move the wheel - most other people can move theirs with considerably less effort. How long is your breaker bar that you are using on the socket? Mine is about 2' long.

Have you done the reversing test - it is this scenario that normally gives first indication that the VCU is suspect requires further investigation.

Garry

[BO00YA]

Hey,

My breaker bar isn't as long as yours Garry. The reason why i wanted to test it was because reversing out of my driveway at full lock it felt tight. I've noticed it only really happens when the car is cold, like in the morning when i go to work. If i get home and leave soon after it reverses out fine..

Ben

[mike 90 RR]

why i wanted to test it was because reversing out of my driveway at full lock it felt tight. I've noticed it only really happens when the car is cold

Garry .. correct me if i'm wrong ..

Ben ....The Viscous unit goes "locked solid" when stuffed /// regardless of the temperature .... Start the car / Drive around the block / Jack up the wheel & then try your wheel test ...... :)

[101RRS]

Hey,

My breaker bar isn't as long as yours Garry. The reason why i wanted to test it was because reversing out of my driveway at full lock it felt tight. I've noticed it only really happens when the car is cold, like in the morning when i go to work. If i get home and leave soon after it reverses out fine..

Ben

It will always get a little tight but not really tight. I was having the same issue when backing out on cold mornings - that was prompted me to check mine and the film what I was doing.

To be honest - it sounds as if your VCU is OK.

Garry

[101RRS]

Garry .. correct me if i'm wrong ..

Ben ....The Viscous unit goes "locked solid" when stuffed /// regardless of the temperature .... Start the car / Drive around the block / Jack up the wheel & then try your wheel test ...... :)

Unlike cooling fan viscous units, the VCU is not temperature related and the fluid does not lock due a change in temperature. The fluid gets thicker as a result of shear forces - internally the VCU has a series of stators and rotors - when the housing with stators attached rotates at the same speed as the input shaft with the rotors attached there is not difference in speeds so the viscosity of the fluid does not change. As soon as there is a difference in speed like when off road (front wheels turning different to the rears) the shear forces in the fluid between the rotors and stators causes the fluid to thicken so the rotors start to drive the stators. Simply the drive is transferred to the rear wheels.

Clear as mud :D.

Garry

[mike 90 RR]

Clear as mud :D.

Understood every word written .... :angel:

Only giving some "input" to this subject, as my RRC has the viscous unit also ... and have had to perform tests on it to check that it's working ;)

Mike

[BO00YA]

It will always get a little tight but not really tight. I was having the same issue when backing out on cold mornings - that was prompted me to check mine and the film what I was doing.

To be honest - it sounds as if your VCU is OK.

Garry

Yeh i think for now i'm not going to get to concerned about it. Although i'm going to keep a very close eye on it and check it regularly.

Thanks for your help guys.

[101RRS]

Understood every word written .... :angel:

Only giving some "input" to this subject, as my RRC has the viscous unit also ... and have had to perform tests on it to check that it's working ;)

Mike

The big difference is that the freelander is front wheel drive with the viscous coupling dealing with the drive to the rear wheels.

The RR is the opposite - it is basically rear wheel drive with the VC taking drive to the front - so I doubt the FL tests apply to the RR - try putting it into gear, applying the handbrake, jack up one front wheel off the ground and see if you can turn it.

Garry