disconnecting haldex - can it cause damage?

Q

quattro1

Registered User
Joined
Jul 19, 2010
Messages
636
Reaction score
7
Points
16
Location
bristol
ok ive just pulled the haldex fuse and took the car for a spin and it really does drive noticably better! with it working the power would die off at 5k revs and just moan to the redline (suspect it needs another remap!) but now with the fuse pulled, the car pulls very nicely!

my question is, can i leave it like this or will it cause damage?

thanks alot
 
Define how it 'drives' better'? I guess it won't damage it with it off, you just won't have 4WD. So long as the front and rear axles are rotating at the same or similar speeds, I guess it can't damage it.
 
well like i said, with the 4WD active it would just feel strangled after 5k rpm and massively bog down when pulling away, now, it actually pulls very nicely to the redline so its not just a psychological thing :blink: could this possibly indicate that somethings actually wrong with the system?? i cant seem to find any reciepts for a service of the system which is abit worrying!


thanks for the quick reply :thumbsup:
 
well i did have a switch in it so i could turn it off whenever i wanted to have abit of fun and ive never broke anything (touch wood) so should be ok.
 
quattro1 said:
ok ive just pulled the haldex fuse and took the car for a spin and it really does drive noticably better! with it working the power would die off at 5k revs and just moan to the redline (suspect it needs another remap!) but now with the fuse pulled, the car pulls very nicely!

my question is, can i leave it like this or will it cause damage?

thanks alot
Click to expand...
plus you would have to change your user name....:)
 
haha ^^ :lmfao:

the switch isnt a bad idea though!! cheers for the quick replies, spot on!
 
when my haldex was faulty i did a lot of driving without 4x4, i thought it drove like a bag of poo! the front wheels would just light up off the mark.
To be honest it has put me off ever owning a fwd car over 200bhp. (unless it had a proper lsd!)
Does your car have an esp button. If so turn it off, this would definitely transform the car.
 
nah doesnt have an esp button :sadlike: i do suspect its partially due to how its currently mapped, i bought it on the promise that it had been remapped prior to having a ko3s fitted, ive had doubts from the day i got it that there was any truth in it, it has flat spots and as said with the 4wd enabled it dies after 4.5-5k, doesnt give me any more than 19mpg no matter how i drive it either! ill drive it for a few days and see what actual differences it has made
 
quattro1 said:
nah doesnt have an esp button :sadlike: i do suspect its partially due to how its currently mapped, i bought it on the promise that it had been remapped prior to having a ko3s fitted, ive had doubts from the day i got it that there was any truth in it, it has flat spots and as said with the 4wd enabled it dies after 4.5-5k, doesnt give me any more than 19mpg no matter how i drive it either! ill drive it for a few days and see what actual differences it has made
Click to expand...

Hmmm, that doesn't sound right to me at all dude.

It should pull the very similar in 4WD as it does in 2WD.

Sounds to me like you have an inherent problem there somewhere, especially with the MPG you're getting.

Have you had it read for fault codes or the like?
 
It must be in your head, as the car is 2wd most of the time, and only 4wd when it senses you have lost traction.

Unless you have a HUUUUGGGEEEEE turbo spooling up at 5k and breaking traction under boost, it should make no difference. It shouldn't however do any harm either
 
Byzan A4 said:
It must be in your head, as the car is 2wd most of the time, and only 4wd when it senses you have lost traction.

Unless you have a HUUUUGGGEEEEE turbo spooling up at 5k and breaking traction under boost, it should make no difference. It shouldn't however do any harm either
Click to expand...

It will most likely be in 4wd mode @5k revs, the Haldex kicks in on throttle position too, and at 5k revs, you are most likely on full throttle.
 
audi upgrades
there was a pdf from Haldex themselves not recommending you go over 30mph with haldex disconnected...reason being is that the parts are still moving regardless of fuse being pulled (you can also lift your handbrake one notch to disengage it)

personally i wont ever be doing it based on what i have read in the past - google that doc if i were you
 
1animal1 said:
there was a pdf from Haldex themselves not recommending you go over 30mph with haldex disconnected...reason being is that the parts are still moving regardless of fuse being pulled (you can also lift your handbrake one notch to disengage it)

personally i wont ever be doing it based on what i have read in the past - google that doc if i were you
Click to expand...

I remember reading that now you mention it.
 
no its definately not in my head it is 100% deffo better in 2wd! the difference is too massive to be a psychological thing! i'll be plugging it back in tonight anyway as i have read the doc mentioned above and dont like the sound of it at all! guess ill just have to wait for the remap and see if that makes any difference, but serioulsy, after 5k it sucks!

cheers for all the good replies, really helpful
 
no i havent had it read for any faults, is vagcom easy enough to use? been thinking of trying it myself!

cheers
 
Erm ya not mistaking it for the common s3 driving characteristic are ya, tails of not much more than 5k
 
it would definitely be advisable to have it vagcom'd before you go mapping it. as stated it tails of above 5k, i dont really feel the need to rev it passed 5k, but perhaps thats just down to my driving style?......
 
audi upgrades
1animal1 said:
there was a pdf from Haldex themselves not recommending you go over 30mph with haldex disconnected...reason being is that the parts are still moving regardless of fuse being pulled (you can also lift your handbrake one notch to disengage it)

personally i wont ever be doing it based on what i have read in the past - google that doc if i were you
Click to expand...

What have you read in the past and is it safe to use the handbrake to turn it off. why would you want to do that anyway?
 
What have you read in the past and is it safe to use the handbrake to turn it off. why would you want to do that anyway?
Click to expand...

Pulling the handbrake up makes the car go into 4 wheel drive mode. Very good for launching at 5k (apparently :p:p:p)
 
I personally don't see why it is a problem considering when you brake it also switches off, the orange haldex controller keeps the 4 wheel drive active while breaking...

But saying that I have also read the same thing about 30Mph thing
 
Pulling the hand brake up turns it off not on :huh:
Click to expand...

I'm not sure about that Dave as I read that pulling up the hand brake tricks the haldex into thinking it needs to drive all four wheels, a method we've been using for 1/4 miles for ages.

If I turn the esp off and lunch the car at 5k the front wheels spin like mad. Pulling the hand brake up makes the car rocket forward without any wheel spin what so ever!
 
Yep do a quick search haldex bible, search handbrake in the PDF

The handbrake switch sends the "handbrake
engaged" signal to the ABS control module
J104 and simultaneously to the Haldex con-
trol module J492.
Whereas the ABS control module transfers
this information to the Haldex control unit in
filtered" form along the CAN bus, the
Haldex control module also receives the
information directly from the handbrake
switch.
if the signal generated by handbrake switch
F9 is picked up, the Haldex coupling clutch is
opened.

http://www.billswebspace.com/HALDEX.pdf
 
Last edited:
What's interesting is that you turn ESP off first, maybe it's the opposite when you do that. Lol I do some testing in my car later :eyebrows:
 
i thought applying the handbrake turns 4WD off cus it doesnt want to drive the rear wheels if the brake is on
 
Hi, very late to this thread but maybe someone is still around...
Have replaced my front ABS sensors that were throwing codes, and the haldex controller, jacked the car up to see if the wheels spun but only the front did. I just now read that opening the trunk or boot will disable the haldex. Is this true?? If it does it could really save me a couple of days of research and labor.
Any other ways to test if 4WD works without jacking the car up on all four?
 
You must log in or register to reply here.

Similar threads

A
Can a remap cause damage to your engine?
Replies
23
Views
18K
badger5
badger5
Andrew@A.L.D
Can damage be done if you over fill with haldex oil?
Replies
9
Views
3K
rupe
R
1.8tplym
Can the MAF do damage?
Replies
13
Views
1K
spliffey
S
A
can it be done
Replies
8
Views
905
nervus
nervus
M
What can cause poor mpg ??
Replies
21
Views
3K
Broken Byzan
Broken Byzan
Top
Back