4 wheel drive - is it?

Greetings all
I assumed my freelander was permanant four wheel drive 100% all the time. Not true someone said, below 1500rpm it is in two wheel drive?
Iam confused, what exactly does the big black thing do that splits the prop shaft in two? What does the ird do and why do we need it?
My defender seems easy compared to this and more reliable.
Butty

Hi Butty . . .let me try and clear it up as a lot of earthlings get there knickers in a twist over this, the power is generated from yer ird unit and as for normal [road driving ] a higher percentage front wheel drive [hence good mpg] the clever bit is the vcu ,driven by a prop from the ird through the vcu to the fdu [rear diff] the vcu determins the percetage power to the fdu if it notices say front wheel loss of traction then kicks in more power to the fdu ,this is all pure mechanical[no wires] so when off road yes it will play four wheel,of course then ya have the best bit the hill decent button ,now that is a bag of tricks,i wont bore ya with that can oh worms, so relax yer really have got a good machine. . . .

It is permanant four wheel drive, the split is 75% front 25% rear all the time. The rest of it works just as the wise Ming has explained.
If you want two wheel drive disconnect the propshaft.

Jerry said:

It is permanant four wheel drive, the split is 75% front 25% rear all the time. The rest of it works just as the wise Ming has explained.
If you want two wheel drive disconnect the propshaft.

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UM yep this is correct,the percentage. . .

Thanks all for the explanation. Its cleared a lot of confusion.
Catch you later
Butty

BUT,in reality most of the bloody things are siezed solid - so yes permanent 4wd,50/50 torque split,worn tyres,knackered rear diff and a bu--ered IRD to top it off.
Fed up with the bloody things !!

they drive so much better with the prop off

clutchdust said:

they drive so much better with the prop off

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Confuses the crap out of the ABS Ecu trying to sort out the TC on slippery surfaces though !!

eightinavee said:

Confuses the crap out of the ABS Ecu trying to sort out the TC on slippery surfaces though !!

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not really............it just puts the brake on on the wheel thats spinning

clutchdust said:

not really............it just puts the brake on on the wheel thats spinning

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Have you not had one with the rear prop removed that puts the 3 friendly lights on after the ecu cant get to grips with the massive difference in wheel sensor outputs - those Wabco Ecu's are crap - had one this morning that insisted that it had internal Ecu failure- after sorting out the Td4 issues and clearing the ABS faults through vehicle maintenance menu rather than "fault code diagnostics" it was fine.Even after my style of "validation of fix" - cane the tits off it and try all the electronic aids to their limits !
If they had the same durability as the early LP's in ABS/TC then fine - but they dont,Wabco make all the bits so what happened ?

eightinavee said:

BUT,in reality most of the bloody things are siezed solid - so yes permanent 4wd,50/50 torque split,worn tyres,knackered rear diff and a bu--ered IRD to top it off.
Fed up with the bloody things !!

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Oh dear ,tut tut,Bob yer needed. . .

ming said:

Oh dear ,tut tut,Bob yer needed. . .

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Another happy hippo owner

i've taken the props off these and never had any trouble with hdc/abs/tc lights coming on

clutchdust said:

i've taken the props off these and never had any trouble with hdc/abs/tc lights coming on

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I can back that as well clutchy, . . .

mondo said:

Another happy hippo owner

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My kinda guy

clutchdust said:

i've taken the props off these and never had any trouble with hdc/abs/tc lights coming on

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Did you actually take the props off and run the car? was it for temp or perm?

clutchdust said:

i've taken the props off these and never had any trouble with hdc/abs/tc lights coming on

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are you guys recommending using the Hippo in only 2 wheel drive?
why? - what advantages are there?
cant be very good off-road?

I have ran mine without a prop on several occasions, no probs at all although mine doesnt have the HDC or EBS.

Real easy to remove and refit, easiest when all four wheels are jacked off ground, allows rotation of the shaft for accessing the torx bolts.

Saves you a bit of fuel as well

No dont take it off road when prop is off, have done his and got stuck on wet grass LOL, basically acts like a car.

Its remarkable how the fdu and vcu do their job when back on the vehicle, they use a similar system in early Range rovers, downside is no low/diff lock but then when would you take a hippo rock hopping.

i know i am asking to be flamed here - but surely it cant be just for fuel consumption? I'v got a V6 which is not known for fuel economy, but the one thing I dont whinge about (see Mondeo) is the fuel consumption - coz i knew it wasn't good when i went for one.