Substitute for Visco?

[LovroD]

Does any body has any idea if that is possible to exchange VC with any other coupling?

[Llanigraham]

NO.
Short and to the point I'm afraid, but no-one has found a cheap, safe or practical system that will replace the VCU, and many have looked.

[LovroD]

I heard from friends which were at Billings meeting in 2007 that some had very expensive kits with AUDI electromagnetic coupling ...

In meaning safe? We are thinking to switch to permanent 50:50 4x4 only in stand still ... Not in movement ...

What about Audi or Subaru 4x4 switches?

If we found something I will let you know ...

[huskyboy]

hi but how do you know when the viscous is broke? and what exactly does it do?

[LovroD]

As far as I found out is that you fill the car likely to be teared apart ...

You fill it on your steering wheel on full lock reverse that car like to break ...

I know that on my car we tested visco in that manner that we lifted only rear left wheel and me and my mechanic did turned it by hands ... No crow bar or something else ...

I hope this will give you some idea about when visco is "dead" or stiff ...

What does visco do? When your front wheels slip on wet ground or in mud or sand then some part of this rotating goes back to rear wheels and that heats up visco fluid in visco coupling and "locks up" rear wheels with front and you have then "50:50" divided torque between front and rear axels ...

[huskyboy]

ok thanks for that!cos my car is driving awful at the moment the car is vibrating realy bad feals like its coming from rear?and a grinding noise from the front when turning corners. jacked the rear right wheel up but could not turn the wheel at all.i have removed the prop at the moment and it has solved vibration and no more grinding as i turn any help would be great

[DIYFreelander]

I had my viscous coupling changed a year ago and at the time I asked the Landrover technician about this concept of jacking one wheel up and turning the wheel with a bar to check the VC. He laughed and said actaully if that happened it probably meant the viscous coupling was slipping too much. And thinking about it he's probably right. The VC has to transfer enough torque to the rear wheels to help propel the vehicle. Surely if you can overcome that by hand or with a long bar then something has to be wrong.
One of the biggest things to remember when changing the VC is make sure you have the new ratio IRD. I changed (yep a DIY job) my IRD + clutch about 18 months ago to correct the ratio that earlier models had. This has made it drive better and so far prevent any further IRD failure. A very basic test I found was make two white paint lines on the prop shaft either side of the IRD and then take it out for a spin. With a knackered VC these lines will stay in-line. But with a working IRD a few roundabouts soon moves the lines out of synch.

[huskyboy]

thanks! thats sounds great advice ill try that and let you know!

[horse280372]

Hi Guys
Replaced my VCU recently as the inevitable signs of failure were apparent. My old unit was not seized as I could turn it with some effort with one rear wheel jacked. However it was becoming rather too stiff and things like rear diff mount, sub-frame mounting point cracked, and horrible noises at full lock were upon me.
I replaced with a GKN unit and new support bearings and it certainly made things feel much smoother, no horrid noises and less rolling resistance at full lock.
Now the car is sound but the point is that a brand new OEM VCU can be turned by hand with one rear wheel jacked. It needs some effort but can be done none the less. The drive split is supposed to be about 60:40 front to rear so under normal conditions the VCU should not constitute a fixed coupling and should allow some slippage.

So check the rear wheel jacked or tipex test to determine the operation of the VCU, if it can move very very slowly then it should be fine.
Hope this helps
Chris

[MFQ]

I'm about to remove my prop as excessive tyre wear seems to indicate my VCU whilst not seized DOES seem to be too tight.....

Does anyone have any more info on the Audi coupling mentioned?

Would it not be possible to substitute some sort of free-standing industrial clutch mechanism in the drivetrain? I'm thinking something along the lines of a small PTO clutch or even an electromagnetic type...

Whilst I'm (temporarily) relatively happy to make do with 2WD for the moment it rather defeats the purpose of having the vehicle at all! It's rare for me to really need 4WD; But when I need it I need it! And even a system that could only be used at slow speeds would be better than what is there!

Can anyone point me in the direction of someone who HAS actually tried to find a substitute????

Or after 23 years of Land Rover ownership do I finally fold and just buy a Jeep? :eek: Or a Landcruiser :eek::eek:Or a Suzuki! :eek::eek::eek: