Baloo588

Hey Jack,

Thank you for helping out in the meantime. I am going to have dealer re-road force my rear tires on my new 20 inch OEM A8 rims to make sure they are less than 10 lbs to eliminate the new tires causing this vibration. I have never bent an OEM rim. Hence why I couldn't decide if my suspension was the issue with this vibration at 70 mph plus though much less than with the winter wheels/tires. My advisor says the bushings are good for another 50k miles! Thats impressive!! I have 102k miles now and do 25k a year so i feel like I should do them all at once (sway bar links and bushings) just to be happy and use the audi credit towards them..... Otherwise I feel like I am shortchanging myself now and will have regrets next year or year after with the price of repair and no audi credit which expires in 1 year...

Still selling your A8?

MP4.2+6.0

I'm suspicious of the diagnosis, but need to defer to a dealer who has seen it first person and presumably knows them. No, the sway bar links should not cause your symptoms, but as Jack said can set up noise. Plus maybe a less tight feeling in suspension in turning.

Given diagnosis, I would nonetheless replace links. They are at least another "link" point to hold suspension in general if vibration would otherwise set in. As Jack said, you can DIY. Extremely easy to get at. If you DIY, you can get in there with a strong light yourself and look at bushings too. Bushings really have to be looked at close up. Cracks often aren't that obvious...until you pull pinch bolt. If pinch bolt off and you move them around one at a time by hand, then you can typically see any cracks or deterioration big time. BTDT, and was surprised on mine the difference in what I could see once I could move them fully by hand.

Meanwhile, if dealer has it right, your remaining areas to review are the wheel balance (as you are going for and the most typical one), tie rod ends (low wear area on D3's and presumably D4s though w/ a modified steering design), and rarely and obscurely the rack adjustment. Don't know if yours is pump/hydraulic or the later electro mechanical BTW. I know how to do the rack adjustment on a D3 and have done so on two, but D4 set up different. Having been all through this over time though on D3 with very subtle vibrations in some but not all conditions and usually looking at wheels and tire as my main suspects, upper bushings were the final answer.

Jack88

I've never bent a rim on anything (knock on wood) but I have had out of balance tires cause issue. Quick and easy fix, and a common problem. Losing a wheel weight is not that hard, especially the old ones on the lip of a rim.

And yes, my car is still up for sale. Not looking forward to watching that one roll away, if I'm honest.

Baloo588

Yeah rims are perfect. We did road force and guess what! Out of the 4 new Michelin Pilot Sport AS3 plus tires that were mounted on the rims last week under 10 lbs road force, 2 of them failed and probably shifted belt and went out of round. They were both in the rear with the right rear at 40 lbs and left at 25lbs!!!! Holy moly!! Thats horrible. The fronts were good at 7 and 9 lbs. I have attached pictures of the road force lbs.

Aas for the suspension. the front control arm bushings are slightly cracked but rear ones are ok according to the independent mechanic and he showed me in person and I saw the cracks whereas the dealer says all bushings are fine. The independent mechanic says the front sway bar links are perfect whereas the dealer says they aren't... So I am confused....

I am going to get tirerack to send me 2 are replacement tires and road force them on my rear rims which are perfect condition and round to get them below 10 lbs like front for glass smooth ride. Then I am going to wait a bit to do the front suspension which isn't bad.

The car now lowers a bit and is recalibrate as it should be.

MP4.2+6.0

Go to my mega post on the very similar D3 bushings, since you saw your front D4 bushings in person with the indy. https://www.audiworld.com/forums/a8-.../#post24620404

At replies 19-22 of that D3 thread, I document each arm bushing with a bunch of photos and some description. Compare that to what you saw on your D4.

Having looked at these a lot before the actual work on my D3, I found as soon as I pulled the pinch bolt, the arm could move around the axis of the bushing quite freely by hand. I just took out one at a time from the hub end and flexed it around some. Then I could see any cracking really easily. Way better than I could with the arm bolted in, though you can twist them a bit by hand even with both sides bolted in. I was sort of shocked at how much more cracking I saw on two of the four once I flexed it more. Not severe, but stuff I would have rated as minor visually in a static position with limited access and visibility from only certain angles was more like moderate once I flexed them more freely and could see from many angles. The pictures themselves show some of the same more obvious cracks for any given arm among the four once I flex it with a socket extension as a lever tool out of the car. As soon as a wheel is off, if pinch bolt is not frozen it is like 10 minutes work to free them up for a really good look.

armend milla

Go to car...vehucle settings...air suspension: trailer ( should be unchecked, you probably have it checked). When air suspension is in trailer mode...id does not lower when in dynamic mode.

A8 2014

I am experiencing the same thing lately after I changed the shock obsorber. Any advice for me?