not your usual vcu topic

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andyfox2005

Active Member
Posts
464
im not sure if this question has been asked before but why cant you just replace the knackered vcu with an engineered solid shaft ? in my head this would make it permanent 4wd right never owned a freelander before now always had disco's i know a guy who could make such a contraption but would it work ? never seen any threads mentioning this ?:confused:
 
im not sure if this question has been asked before but why cant you just replace the knackered vcu with an engineered solid shaft ? in my head this would make it permanent 4wd right never owned a freelander before now always had disco's i know a guy who could make such a contraption but would it work ? never seen any threads mentioning this ?:confused:

There has to be some slip in the system which is where the VCU comes in ;) it allows the front and rear propshafts to rotate at slightly different speeds to take into account the different front /rear gearing, different tyre diameters and different distances the the front and rear wheels take when cornering. If the propshaft was solid front to back the rear diff and IRD would last a very few miles!! It would be no better off road and hopeless on it for the short time it lasted ;)
 
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So yer can't remove the vcu/props and replace with a length of scaff pole?

[I should edit this to clearly state yer can't do the above as the ratio of drive front to rear wheels is different. So don't try it]
 
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genius-meme.jpg
 
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maybe its time to buy another disco this thing is giving me a head ache already what ever happened to simple engineering ?
Tell us yer problems and we'll laugh, shorry tell yer how we fixed ours.
 
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maybe its time to buy another disco this thing is giving me a head ache already what ever happened to simple engineering ?

The VCU 4x4 system is simple, there are just a few fundamental principles you need to be aware of.

Number 1: When ewe is on full lock all four wheels is turning at different speeds. This is why full time 4x4's have massive turning cicles as else them's transmission would melt.

Number 2: The Freelander's rear diff ratio and the IRD ratio (similar to yer tratter's transfer box) is different. This is to take up the lag when your front wheels start to slip so that the VCU engages quicker and you get power to the back wheels when you needs it.

Number 3: Because of this system the Hippo is much more "car like" in the way it handles, which is why many of us like it. As a daily driver it feels very civilised.

Number 4: On the Hippo 2's ewe have them new fangled Haldex units wot likes to break alot. They allows you to select 2wd, 4x4 auto or full time 4x4. The Hippo 1 is basically in the second mode at all times, which for the most part works just fine.

If you want an in depth article on how VCU's work and why they is actually quite clever there is a link in my signature :).

Stick with it, it will grow on you :).

Will.

Edit: Jesus I really slipped into Hippo speak there :eek:! He is contageous!
 
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This is why full time 4x4's have massive turning cicles as else them's transmission would melt.


have yu looked into the Nissan Juke auto 4x4 drive system - that is awesome :)
As well as splitting torque front and rear, with up to 50 per cent being sent to the back wheels, the split can also be made side-to-side across the rear axle. By monitoring vehicle speed, wheel speed, gear position, steering angle, lateral G-forces and the car’s yaw rate, torque distribution to the outside rear wheel can be increased in corners to cut understeer and help the car round. Half of the engine’s total available torque can be sent to either rear wheel.
 
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Just did some reading on it MHM, sounds like it would be an awesome system to have on a road going rally car or similar. But the Juke is so low that I don't know how useful it would be off road, even on the easier lanes. Still, just goes to show that controversial styling often belies clever engineering. #Evoque.
 
The VCU 4x4 system is simple, there are just a few fundamental principles you need to be aware of.

Number 1: When ewe is on full lock all four wheels is turning at different speeds. This is why full time 4x4's have massive turning cicles as else them's transmission would melt.

Number 2: The Freelander's rear diff ratio and the IRD ratio (similar to yer tratter's transfer box) is different. This is to take up the lag when your front wheels start to slip so that the VCU engages quicker and you get power to the back wheels when you needs it.

Number 3: Because of this system the Hippo is much more "car like" in the way it handles, which is why many of us like it. As a daily driver it feels very civilised.

Number 4: On the Hippo 2's ewe have them new fangled Haldex units wot likes to break alot. They allows you to select 2wd, 4x4 auto or full time 4x4. The Hippo 1 is basically in the second mode at all times, which for the most part works just fine.

If you want an in depth article on how VCU's work and why they is actually quite clever there is a link in my signature :).

Stick with it, it will grow on you :).

Will.

Edit: Jesus I really slipped into Hippo speak there :eek:! He is contageous!

oh i do like it alot to drive but like anything if your used to it your feel much more comfortable and im not used to freelander. seems to me i have bought one with all the text book problems, dodgy injectors missing vcu and props ect but it does drive nice much nicer than a disco but not as handy i understand how the vcu works after reading countless threads but i didnt know about the differant gearing between front and back im used to having just one prop nothing inbetween
 
The VCU 4x4 system is simple, there are just a few fundamental principles you need to be aware of.

Number 1: When ewe is on full lock all four wheels is turning at different speeds. This is why full time 4x4's have massive turning cicles as else them's transmission would melt.

Number 2: The Freelander's rear diff ratio and the IRD ratio (similar to yer tratter's transfer box) is different. This is to take up the lag when your front wheels start to slip so that the VCU engages quicker and you get power to the back wheels when you needs it.

Number 3: Because of this system the Hippo is much more "car like" in the way it handles, which is why many of us like it. As a daily driver it feels very civilised.

Number 4: On the Hippo 2's ewe have them new fangled Haldex units wot likes to break alot. They allows you to select 2wd, 4x4 auto or full time 4x4. The Hippo 1 is basically in the second mode at all times, which for the most part works just fine.

If you want an in depth article on how VCU's work and why they is actually quite clever there is a link in my signature :).

Stick with it, it will grow on you :).

Will.

Edit: Jesus I really slipped into Hippo speak there :eek:! He is contageous!
where did you get info for no 2 ?
 
where did you get info for no 2 ?

Well the different diff ratio thing is pretty common knowlege, not sure what the exact ratios are but it's around here somewhere.

The lag thing I've seen mentioned and it makes the most sense, why else do it? It's also possible that it helps allow for a tighter turning circle but that's me speculating. So basically the info came from hours and hours of forum and tech bulletin browsing aswell as discussions with people in the know :).

FECK: In my fury I forgot the search rule. Looks like this has been done. Apologies fellas.
 
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