# haldex problem



## joinerblue (Oct 14, 2008)

Hi i have only recently bought my first tt had an A4 previously, i took it to an independant Audi garage today to have it checked out and he told me the front wheels were spinning. To let you understand i have a 2003 180bhp quattro, he put it on the ramps and put it in gear and the front wheels went round but the rear wheels didnt. when he put the car on the computer no faults showed up with the haldex but when he put the wheels into drive the front spun and the rear stayed still.
Any thoughts? he thought it was the haldex then he thought it was the haldex control unit


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## conlechi (May 6, 2006)

To my understanding (someone will be along to correct me if i am wrong! ) 
,the quattro system is governed by the haldex unit , the TT is predominatly front wheel drive until it's is driven hard ,under acceleration or hard cornering then the haldex tranfers some of the drive to the rear wheels .
On the ramps the front wheels only will be moving .

So your haldex unit is probably ok

Mark


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## Wak (May 6, 2002)

did he try this test a few times and then check for faults?

Some faults need to happen a couple of times before they get registered.

1. if there are no haldex controller faults then it could be the mechanical side
2. the mechanical side needs to engage the haldex and sense that the wheel speeds are not in sync with the front wheels to guess there is a mechanical problem. this may take a few goes to achieve.
3. have you checked the haldex oil level? a change may help!
4. although this would have stopped diagnostics, have you checked the haldex fuse?


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## Wak (May 6, 2002)

conlechi said:


> To my understanding (someone will be along to correct me if i am wrong! )
> ,the quattro system is governed by the haldex unit , the TT is predominatly front wheel drive until it's is driven hard ,under acceleration or hard cornering then the haldex tranfers some of the drive to the rear wheels .
> On the ramps the front wheels only will be moving .
> 
> ...


Hi Mark, the haldex unit should be engaged when more than 6 degrees of wheel slip is detected between front and rear, with the wheels in the air it should try to engage the rear wheels. :?


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## joinerblue (Oct 14, 2008)

hi guys this forum is great really appreciate your help here.

the mechanic took the car for a spin so i have no idea how many time he trested it, where would i find the haldex oil level to see if its ok and where is the fuse . sorry to be a pain.


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## Wak (May 6, 2002)

level checking is described here
http://www.kisolutionz.com/ttforum/haldexoilchange.pdf

Typically Fuse 31
http://www.wak-tt.com/fuses/fuses.htm


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## timvgti (Mar 14, 2007)

I think I have the same problem...
The front wheels are also spinning (esp off) when it's wet...
:?  [smiley=bigcry.gif]


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## prt225TT (May 7, 2007)

Maybe you've got a FWD 180bhp :roll: :roll:

Someone had to say it, might aswell be me :lol: :lol:


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## joinerblue (Oct 14, 2008)

the mechanic checked that the rear wheel drive shaft was there when it was up on the ramp , suppose it wouldnt be the first time someone stuck a quattro badge on a car when they were selling it.


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## CHADTT (Jun 20, 2007)

Check that your handbrake is fully off.

If the handbrake switch is actuated the haldex drive is switched off. :wink:

You would also see the handbrake icon on the Dash.


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## timvgti (Mar 14, 2007)

The handbrake is fuly off...
But I feel it's always only front wheel driven and when I turn off esp/asr, the fronts begin to spin in rain or when going very fast on a roundabout...

What's wrong with my haldex?
I recently refilled the haldex oil and filter...


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## kite (Sep 3, 2006)

I had a mech. fault on my haldex when scanned with vagcom.
I needed a new diff. [smiley=bigcry.gif]


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## Guest (Oct 19, 2008)

Think i have possibly the same fault, my garage placed the car on a two post ramp, handbrake off and engine running and the rear wheels didnt turn when the front were spinning,

They checked it via vagcom - no faults
checked the No.31 fuse - fine
changed the haldex oil and filter.

any idea\'s?


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## Mici (Sep 25, 2006)

Silly question. Is VAG-COM _really_ needed to change the haldex oil and if so, what is the purpose of it? My Haldex is in need of new oil and I was thinking about doing it myself but don't have VAG-COM.

Also, does rear diff have another oil or is it the same as haldex?

Mici


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## TTKING (Aug 6, 2008)

I've recently changed my haldex for the upgraded vision so if you need a haldex controller just let me know send pm
More than likely it i will put on ebay or for sale section very soon


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