High speed vibration

[Saff]

Originally Posted by paulrstaylor

Swapping front to back would help isolate the issue for sure

[ainarssems]

Originally Posted by Saff

Hi Strummagnet, yep each axle set match

If the front to rear are significantly different tread left that can cause issues with quattro say if fronts are 2 mm and rears 8mm same make and model. I think it's something like 2.5mm recommended max difference in tread depth between tyres. But if they are different make/model they may be slightly different construction resulting in slightly different rolling diameter also causing issue.

[Saff]

Rears are new and fronts about 5-6mm. Cheers

[Saff]

After much head scratching I decided to swap the n/s/r for the spacesaver and take it for a slow run. I took it up to just nudging 60 (I know I know) and there was no sign of the vibration so I may have found it. It’s booked in with a local specialist (Burscough Lancs) for Tuesday. I’ve asked them to do both rears just to make sure. Fingers crossed and I’ll update.

Steve.

[Saff]

An update to this issue.

All wheels checked out ok for true. I’ve had them all re-balanced and had a 4-wheel alignment done. It was quite far out in fact. No improvement. I’m going to assume that wheels and tyres are not the issue and turn my attention to driveshafts. Maybe this thread should move to transmission?
I’ve been googling a bit and found D4s having issues with the centre bearing bush on the propshaft. Apparently the bush, after time, allows the shaft to wobble about causing speed-related vibration. Not sure if I’m talking myself into this but the vibration could be emanating from the transmission tunnel.
I think I may have to surrender here and hand it over to an Audi specialist to diagnose and cure and be prepared to bite the bullet over the cost.
Cheers, Steve

[Saff]

OK, I may have this issue solved now. Sorry about the long post.

I swapped the road wheels front to rear and there appeared to be a change/slight reduction in the vibration but Mrs. Saff said it still felt the same to her so maybe my imagination.

My son drove the car and he could feel the vibration and also a pulse in the brake pedal seemingly in sync with the vibration. We had a look at the rear discs/pads and there was a lip on the discs and also another ‘step’ on the discs. The pads had loads of meat left. I decided to change them and my trusted garage did them yesterday for me.

On collection they showed me the old discs, the inside face was in a terrible state, almost completely rusted with a small track of clean metal. The surface mating to the hub was also red rusty. Could the discs have been fitted without due attention to cleaning the hub face?

The good news is that there is absolutely no brake pulsing now and as far as I can tell the vibration has gone. I’m a little hypersensitive to road surfaces and possibly imagining a vibration when it’s just the bum condition of the M58.

I’m not 100% at ease yet but maybe that’s just my paranoia. I’m hoping that I’m comparing the ride to my outgoing E-class with 16” rims and big bouncy tyres against the 19s on my D4.

Fingers crossed and thanks to all the input on here. Steve.

[Saff]

OK I’m still plagued with this pesky vibration. I’m convinced that it’s wheel related but everything (so far) has checked out ok.

Question: Has anyone had experience of the Hunter Road Force wheel balancer?

Desperation is leading me to invest hopefully not too much money in getting all wheels/tyres checked out on one of these to either prove or better still cure a wheel/tyre issue. If all checks out ok and the problem is still there I’m going to have to give it to a professional . Ho-Hum.

[Saff]

The saga continues...

Can any learned person possibly find out the part no. for a 2010 D4 4.2tdi prop shaft please. Could it be 4H0521101E ?

I'd be most grateful. Steve

[steamship]

Originally Posted by Saff

Could it be 4H0521101E ?

It is indeed (assuming it's not a LWB model). Superseded versions to look out for are 4H0521101J and 4H0521101K.

[Saff]

Thank you Sir!

Both rear hubs and bearings have been changed as they were very worn and throwing the rotation of the rear wheels out. No change to vibration. Propshaft was removed and taken to a local specialist where it was pronounced 'knotchy'. They offered to rebuild it but wouldn't be able to do anything with the front joint ans there are no available parts. As a new propshaft is over £2k plus vat I agreed. Got the car back from the specialists yesterday and they said the vibration was still there. Not Happy! I later took the car for a 70mph+ run and I honestly couldn't feel any vibration. I don't know whether I'm going a bit mad or there really isn't any vibration at all. I'll carry on using the car and in the meantime try and locate a low mileage used item, get the balance checked and have it fitted. It seems to have been the culprit all along. Thanks for your help. Steve.