Mk 4 bora scraping noise.

[Wighty654]

Alright, ive removed fuse 31 which makes it a fwd. I then tested the turning thing and no noise. is this gonna be a haldex problem or a diff problem or is there no way to tell without ripping things to pieces?
Am i right in saying the haldex is basically a hydraulically controlled gearbox that shifts the power from front to back depending on grip?
If so could it be the haldex not engaging properly because of the controller or worn internal parts?
Has anyone else had a similar problem?

[RolfGolf]

Has anyone else had a similar problem?

There was a thread on here a while back where someone spoke of the haldex causing crabbing during tight, low speed turns - it's not something like that is it?

[kapowww]

Alright, ive removed fuse 31 which makes it a fwd. I then tested the turning thing and no noise. is this gonna be a haldex problem or a diff problem or is there no way to tell without ripping things to pieces?
Am i right in saying the haldex is basically a hydraulically controlled gearbox that shifts the power from front to back depending on grip?
If so could it be the haldex not engaging properly because of the controller or worn internal parts?
Has anyone else had a similar problem? <--yes lol

Ouch, thought so bro. Read through the thread I linked you earlier.

Have a read through this thread and hopefully it won't be you but it is a pretty common problem on the 4mo.

http://www.vwwatercooled.com/forums/f14/bora-4mo-esp-kicking-slow-speeds-60037.html

A few guys here have had their haldex/rear diffs replaced. From memory the haldex and rear diff are one unit? If the haldex isn't serviced every 60k or so this problem seems to occur. Haldex is like the centre diff.

Mine cost $2000 to fix but thankfully was under warranty from the second hand dealer. I got quotes up to $3000 but I believe others have got cheaper ones.

[Wighty654]

Yeah it's sounds like it could be something like that except for one thing, there isn't any wheel dragging/spinning or crabbing. That's my one hope that it isn't gonna be expensive :p

[Manaz]

A few guys here have had their haldex/rear diffs replaced. From memory the haldex and rear diff are one unit? If the haldex isn't serviced every 60k or so this problem seems to occur. Haldex is like the centre diff.

The Haldex controller is separate to the diff itself - and it would be worthwhile servicing that (the fluid and a new filter don't cost much) to see if that helps. And yes, a replacement rear diff tends to be expensive - if you're going to do that, I'd probably suggest that you look at a third party diff centre (Peloquin or Quaiffe, Wavetrac don't do rear units unfortunately) to see if you can get an improved rear diff at the same time (assuming you don't need a whole near rear end, but rather just the centre).

The crabbing issue people experience is generally related to upgraded haldex controllers (remembering that the stock Haldex controller leaves your car in FWD mode most of the time, only hooking up the rear diff if slip is detected, and disconnecting the rear as soon as you get off the accelerator - the blue haldex upgrade is more aggressive but still disconnects the rears under deceleration/braking, only the comp/orange controller leaves the rear connected under brakes), generally just the orange/comp controller - and even then, talking to HPA, they tell me the issue is that the issue is generally that some cleaning is required of the haldex unit and the needle valve it uses to control the flow of haldex fluid.

[kapowww]

The Haldex controller is separate to the diff itself - and it would be worthwhile servicing that (the fluid and a new filter don't cost much) to see if that helps.

Yes the haldex controller is separate to the diff, but the actual haldex diff is housed in the same case as the rear diff so it all gets changed together.

As Manaz said first step is to service the haldex and hopefully this fixes the issue. Have you checked your log books to see when this was done last?

[Wighty654]

I jacked the car up today and had a look under it. The filter nut looks like a huge pain to get off so I can replace the filter. Have you guys done it or have you just taken it to a garage?
Im also about to order a service kit for the haldex now from the uk. Is there any specific tool needed to clean out the haldex needle or is it something I can just blow clean with the compressor?

[Golf-Sam]

I jacked the car up today and had a look under it. The filter nut looks like a huge pain to get off so I can replace the filter. Have you guys done it or have you just taken it to a garage?
Im also about to order a service kit for the haldex now from the uk. Is there any specific tool needed to clean out the haldex needle or is it something I can just blow clean with the compressor?

check this thread for the Oil/Filter change .. http://www.vwwatercooled.com/forums/...res-64005.html

[Wighty654]

Thanks for the link, i thought it was going to be an awkward one, almost not looking forward to it

[Wighty654]

Just to update:
Serviced the haldex, oil and filter change, took her for a quick very twisty drive and not a sound from the haldex. The oil I removed was only about a third of what should of been in there. Figuring that was the problem

[mariob]

man, good news.

I just bought a replacement diff/haldex, was lucky to get one locally...off a test vehicle with bugger all kms...now all i need is a replacement propshaft...mine bound up and completely destroyed the unijoint on the shaft...Jmac was pretty surprised when he got under there and saw the mess coming out of the transfer case

[Wighty654]

ouch!!! That looks a little messy to say the least. Hope you get her running soon enough mate.