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Transfer box


Badger_1

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Never owned or driven a 4x4 before so excuse me if the answer to this is obvious.

What does the transfer box do on a freelander? I'm guessing its something to do with the four wheel drive.

Can someone explain the principle please. Also is the four wheel drive selected from stationary or can it be engaged whilst the vehicle is moving?

Early days for me and I'm doing my homework to see what I'm about to let myself in for.

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Never owned or driven a 4x4 before so excuse me if the answer to this is obvious.

What does the transfer box do on a freelander? I'm guessing its something to do with the four wheel drive.

Can someone explain the principle please. Also is the four wheel drive selected from stationary or can it be engaged whilst the vehicle is moving?

Early days for me and I'm doing my homework to see what I'm about to let myself in for.

The Freelander is PERMANENT four wheel drive and therefore not selectable.

Technically the Freelander does not have a transfer box but an Intermediate Reduction Drive, that reduces the drive from the gearbox and "splits" the drive to front and back axles.

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Badger

The Freelander does not have a transfer box.

As stated above there is a unit called the intermediate reduction drive, which splits the drive between the front and rear "axles".

There is also a viscous coupling which allows for permenant 4wd without causing transmission wind up - as long as it is working.

"Wind up" is a torsional load on the transmission caused by the four wheels turning at different speeds when cornering.

A transfer box houses in effect a two speed gear box, which are referred to as High and Low range.

Once either of these gears is selected, the main gearbox is used normally as in a car.

HTH

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There are know issues with the IRD, viscous coupling, and centre bearings on the propshaft.

AFAIK it is the viscous coupling seizing that tends to damage the IRD.

Have a look at the wear pattern on the tyres, as I gather that they tend to "feather" when the viscous unit has seized.

You might also notice on roundabouts if you lift off the throttle on a tight lock, that the vehicle slows abruptly.

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Is part number 3 on the diagram on the right the viscous coupling I keep hearing about?

I can see why the IRD is so expensive, are they a big job to replace on a driveway?

Yes - part number 3 is VCU (Viscous Coupling Unit)

I do know someone who has repaired IRD on driveway (I have a link to pics and article he did if I can find it - I'll post it)

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Here is a diagram I put together to explain this graphically to someone a while ago

fldrive.jpg

Grate lay out.

If anyone is interested

The main shaft is the part I tended to shear and the rear drive section is the part that snaps off when you really start to push it.

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I don't recommend it as 0nly 40% of the power goes to the rear
Surely with a locked/b*ggered VC and no front shafts 100% of the power is going to go to the rear? Just wondering if the IRD would spit its dummy or be OK with it.
It would hold up but I wouldn't recommend too many traffic light grandprix

... on the premise that 100% of the power would be diverted down what is designed for 40%?

Cheers

Blippie

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  • 9 months later...

Hi guys,

I am new to this forum and new to freelender ownership. At the momenet I am somewhat regretting it. I had a slight vibration which never having owned a 4x4 took to be the result of them being a bit aggricultural!? This developed to a knock and bang and motorway recovery job. Took off the prop and had a look at the (Hypoid?) drive gear for the rear wheels. It is destroyed chunks of metal floating around, part of the housing looks like it's been eaten by mice etc. The gear connected to drive gears both to the left and right. I would like to know if I remove the hypoid gear and blank the back of it off with a plate and gastket will it run ok in front wheel drive as these two other gears are also quite badly damaged?

I know this is not desirable but there is no cash in the pot and I need the transport. This will give me a chance to save up for the parts to refit the ird at later date. I dont need the 4wd drive function I bought more to use for work and occasionally pick the kids up from school.

Cheers

Bigdaddyadd

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  • 1 month later...
depending on the year of freelander you may have problems with the ird box. landrover changed them in late 2000. anything before i`d be wary of

I have just purchased a 2000 model, registered in sept 2000. How can I tell if I am at risk? Is there an easy way to tell the ratios in the ird without taking it apart and counting teeth? :ph34r:

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The main risk is seizure of your VCU, which then gess on to put strain on the IRD.

There are two good tests for the VCU, the "Ashcroft Test" (described fairly recently by Fridge Freezer in a post) and the "Tippex Test" (where you daub a blob of paint on the propshaft on either side of the VCU.) Both have been decsribed at length already on the forum.

Cheers

Blippie

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  • 4 years later...

hi guys, I have a been getting vibrations in my 98 Freelander, I thought it might be the replacement used tires I put on but reading your posts I am concerned that it might be the rear prop.

I was considering removing it to improve fuel consumption anyway, and it sounds like it may be important to do it sooner rather than later.

Are there covers for the diff available or would I need to fabricate them, and how hard a job is it to remove the Prop? anything I should know before I attempt it?

Cheers

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You don't need to cover anything, just unbolt the propshaft from the diff & gearbox. People remove the IRD drive-flange & blank off the hole but unless the IRD output gear/bearing/seal is bu&&ered there's no point as it won't be doing anything if there's no prop.

Ran my last freebie for tens of thousands of miles like that, current one is running like it at the moment pending new support bearings.

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