4-Motion vibration

[oysbergl]

Hi,

Did you come to any conclution about the vibration? I have the same problem on my Passat 08. Changed the rear diff w/haldex - no difference. Vibration is gone if i disconnect the Haldex.

Hopefully you have found something out


- Fustrated Norwegian

 

[smgcowfoldparts]

We had one that was vibrating at 60mph in 6th gear which was caused by the haldex pump. That was changed and fixed the issue. Diagnosed by disconnecting the pump and driving the vehicle which stopped the vibration.

cheers

 

[bvddobb]

Hi Brom, Skoda UK didn't know what was causing it to start with, the answer came from Audi, as several TT's had the same problem. So I'm not really surprised VW commercial don't know.
This link might be helpful.
http://www.vaglinks.com/Docs/VW/Misc/VW ... yGuide.pdf
Best of luck.



Sent from my iVan using smoke and mirrors.

here is a more recent one: http://www.vaglinks.com/vaglinks_com/Do ... Haldex.pdf

 

[stew]

Hi,

Did you come to any conclution about the vibration? I have the same problem on my Passat 08. Changed the rear diff w/haldex - no difference. Vibration is gone if i disconnect the Haldex.

Hopefully you have found something out


- Fustrated Norwegian

So, after changing the diff, the haldex and a propshaft, they got through to a VW expert and said the last thing it could be is the tyres. They switched to my winter set and it went away. There was too much variance between front and rear tyre depths which caused it (in this case, the front tyres were newer), but I didn't get an explanation of exactly what this does to the entire AWD system (partly due to my poor German)...

 

[Andresz]

Hi,

Did you come to any conclution about the vibration? I have the same problem on my Passat 08. Changed the rear diff w/haldex - no difference. Vibration is gone if i disconnect the Haldex.

Hopefully you have found something out


- Fustrated Norwegian

So, after changing the diff, the haldex and a propshaft, they got through to a VW expert and said the last thing it could be is the tyres. They switched to my winter set and it went away. There was too much variance between front and rear tyre depths which caused it (in this case, the front tyres were newer), but I didn't get an explanation of exactly what this does to the entire AWD system (partly due to my poor German)...

This is very good point with the difference of effective tyre diameter. It seems to be the case that a few of these situations occurred after tyre change. It is pretty obvious that in the 4x4 system, where front and rear drives are coupled, the torque between them is uneven in case of wheel diameter difference. Simple only when known, thank you for sharing this with us.

 

[oysbergl]

I also was thinking since when we disconnect the haldex and the vibration dissapear it could be something related to load. I was thinking flywheel/clutch at first. Then second hand CV joints, driveshaft between gearbox and haldex. Engine/gearbox/haldex/rear suspension mounts.

The way I think i can eliminate everything in front as gearbox/engine mounts and flywheel/clutch is to disconnect the Haldex and hook my caravan trailer at the back and try to have a huge amount of load with only FWD since the power going trough the flywheel/clutch will be just as high or even higher then.

 

[oysbergl]

hello . thanks for the tip, today switched to four new tires and the sound is now gone. :clap

 

[Andresz]

hello . thanks for the tip, today switched to four new tires and the sound is now gone. :clap

This is a very important lesson not only for the California 4-motion owners, but any other user of 4x4 vehicle.
Fortunately in my Grand Vitara I always have even tyres diameter, due to fact that every half a year a switch to winter or summer wheels mixing placement of the wheels with this occasion, so the wear is even.

 

[stew]

hello . thanks for the tip, today switched to four new tires and the sound is now gone. :clap

This is a very important lesson not only for the California 4-motion owners, but any other user of 4x4 vehicle.
Fortunately in my Grand Vitara I always have even tyres diameter, due to fact that every half a year a switch to winter or summer wheels mixing placement of the wheels with this occasion, so the wear is even.

Right, if you rotate wheels every 6 months or so as advised, it's fine, but when you get an unrepairable puncture in one tyre, what do you do? It's happened to me twice already...

If all 4 are relatively new, then you just replace the bad one. But when all 4 tyres are at half-life or worse, you only have 3 options, least favourable first...

1) Replace all four tyres
'Crazy' as it's a very expensive outlay and you're throwing away 3 perfectly good tyres.

2) Replace both tyres on the same axle
Depending on the wear, this can lead to the 'vibration' since there is too much difference in tread depth between front and rear axles.

3) Replace the bad tyre and get it 'shaved' down to the depth of the other 3
I've only heard about this in the US - has anyone done it?

There really should be something in the 'brain' of the 4Motion system that can detect and average out the differences in speed between axles due to wear. This would put the system back to a 'baseline' state without constantly trying to compensate as though there is a 'real' difference in speed between axles due to loss of traction for example. As I understand it, haldex is not purely a mechanical device, but controllable...

 

[KernowLad]

I don't think it's related but I had to have an entire new rear diff/shafts fitted when mine leaked oil.
Had it not been under warranty it would have been very expensive!

 

[Andy]

Wasnt the fact that 4 motion tyres should ve replaced at same time discused elsewhere ?

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