Front wheel judder/slip in full lock/reverse

[Sporty]

Hi folks, have been delighted with MY15 RS4 since picking it up in June, have been listening out for any DRC 'knocking' noises and so far so good .

One thing that I've started to notice is that when on full lock and reversing out of garage the o/s front wheel seems to judder and sort of slip, it feels like its trying to gain grip and doesn't sound good.

It may be cold start/cold weather thing as once up and running it's fine and there's no issues/noise so don't think (hoping) its not a front suspension problem, car's done 10k miles, still under warranty and will go in for first service in January (oil change done last Jan) so just wanting to try and find out is there's an issue that needs to be sorted.

Any views/guidance much appreciated.

Cheers

[ARSEY4]

Mine does it too. Ive had a few cars that do it so think its pretty normal.

[RIV]

Sounds like your tyres are getting worn out... b7 does the same thing

[Madelvic]

My S4 and current RS4 both do this. Think it is normal. The suspension clunk I have isn't posting.php?mode=reply&f=61&t=122594&si ... ed790e9939#

[johnnydog]

My previous B7 did it and my current B8 does it - when reversing off the drive on full lock, it is as if the tyres are scrubbing sideways. It appears to be the right hand tyre on left lock and vice versa. I've also driven other RS models that do it as well. It has done it with Conti's, Pirelli and Michelins, so I would say the make of tyre isn't really the issue. I think it is the width of the tyres and the Quattro system that is the cause. But as it seems to be a common symptom, then I would argue it is a 'characteristic' of the car. Now where have I heard that expression before........(???!???)

[RIV]

I still think tyre wear makes it worse

[Macdaddy]

I still think tyre wear makes it worse

My car suffered this last year badly, My tyres were down to about 3mm and it got worse until they were changed on the limit.

New tyres and it went away, now started to come back as they are probably down to 3-4mm again so have to agree as the tyres wear down it makes it worse.

[johnnydog]

I guess as the tyres wear, it will probably make the symptoms worse with the tread depth reducing, as theoretically, there will be less grip available. However, I have just fitted a brand new set of Michelins to my B8 only 2 weeks ago to replace the original Pirellis, and it still does it.
It's probably a lot to do with the steering geometry and set up as well, combined with the tyre profile of 30 which doesn't allow much flexing of the sidewall. A tyre with a say 70 profile will have a lot more flexibility of the sidewall, so on full lock when you see the outer wheel 'leaning' inwards as you reverse, there will be a lot less tendency for the tyre to 'chatter' on the road surface.
I have just had a full 4 wheel alignment carried out at Audi, with all the adaptations flowing a replacement windscreen. The car seems to be more 'planted' now and drives a lot better - that is probably mainly due to the tyres but a few minor tweeks were made to the alignment and the steering wheel centred, which psycologically have made a great difference, as a slightly off centre steering wheel really does my tree in.....

[Sporty]

Guys thanks for the feedback, very useful and much appreciated, doesn't look like there much to be concerned about as it appears to be more of a 'characteristic' of the car

I checked out tyre wear and still a pretty healthy 8mm on front o/s, driver side front was replaced with new Pirelli by the (non Audi) dealer back in June when I bought the car due to side wall damage picked up during RAC pre-purchase inspection, although the sound isn't so bad from driver side so tyre wear may be a factor.

Thanks again

[Grizwold]

Mine does it too , as you say reversing off drive
On a lock skipping , jumping , juddering .
Feeling through steering wheel ?
Must be the general set up with rs cars

[innercry666]

The judder comes from the front differential unlocking when you go to full steering lock and are reversing at slow speed.

[Sammyb349]

It's due to wide track Quattro. Will also happen going forward in full lock. It's the fact that the inner tire and outer tire travel at different speed and outer tire gets "dragged" to keep up. A quick forum search will give you all the answers as this has been asked and responded to before.

[Ian_C]

viewtopic.php?f=47&t=122560

[geoffdunk]

This is common for quattro cars and exaggerated by larger wheels. I had in my S4 and RS4 and its called diff scrub and caused by one or the other or a combination of low tyre tread and old diff oil.

I had it on my S4 with good tyres and had the diff oil serviced and the problem went away. When my RS went in for its 1st service it was one of the issues I added to the service sheet and was being caused by low tyre tread, two new tyres up front and the problem was completely gone. @nd service just done 36k and it was starting to do it again, front tyres are good but the front diff was serviced and had new oil, now no diff scrub.

[geoffdunk]

It is normal and all quattro's do it but it can be addressed and should be. In high mileage cars its the diff itself causing it which is obviously a bigger job.