nielsn

Ok, lets try this again. I just typed a nice long thread about this and for some reason, after hitting some f'n key on the keyboard it wiped it out. so this time I'll get to the point. I don't post a lot on this forum, but I read a lot and I really like the input from the community. A lot of good ideas out there. So, .... I have a 2009 A6 3.Ot, wife's car. I recently installed new Koni FSD shocks at 96,000 miles. it has Eibach pro-kit springs on it since 10K with the stock shocks. I also installed a new rear H&R sway bar at the same time the shocks were installed- about a week and a half ago. other than that I am also running Konig lace 19 inch rims (installed around same time as springs) on Michelin supersports in 255/35/19. no other suspension mods. the car prior to new shocks had no vibration issues through steering wheel or felt through seat on highway with old worn shocks on the eibachs. the only thing I can say is the rebound was a bit slow and they felt mushy and the car seemed to really dive and bounce a little more than I thought it should on highway. So again, no vibrations. I had the new shocks and sway bar on for a day and started noticing a vibration on certain roads and certain lanes on freeways. smooth parts of freeways. This was right after install. a week later I decided to have the wheels/tire high speed spin balanced. all wheels were out of balance. this was 2 days ago. problem did not go away. then I decided to take car to Les Schwab for an alignment since struts were replace, I had them inspect for any front end damage, or worn parts. they found no issues. So question to the group.. could the worn shocks have masked a front end, steering, or tie rod, bearing issues that I never felt before and now the new tighter shocks I'm just feeling more? Or, even with my tires and wheels balanced, because I have low profile tires, lowering springs and stiffer performance shocks, I now feel every little imperfection? or is there perhaps a larger issue with the wheels or tires? I'm open to opinions suggestions, rants, complaints, whatever may shed some light on this mystery. I really am scratching my head on this. nice luxury car, with new shocks should NOT be having this much feedback through wheel and vibrations on smooth roads. let me know what you guys think, thanks, Damn, I guess this was a pretty long post after all...

BillBoost37

On other vehicles, I have seen vibrations from lowering and axle geometry. I have no idea if that affects this platform or how low you'd have to go in order for that to be an issue. Just a thought.

FL C6.5 Avant

very likely.
also, there is a difference between 'high speed balance' and road force balance. have you road forced? to what residual?
were the new rims checked for runout on the machine prior to mounting tires?
do your new rims have a 57.1 CB? did you replace the factory ball seat lugs with (presumably) the correct CONE seat lugs for the aftermarket rims?

nielsn

I can't answer all those questions, but I can ask the tire place about this. that's very technical tire/wheel information that I'm not familiar with. "hopefully" the tire shop will know what you're talking about

FL C6.5 Avant

road forcing (google Hunter 9700) is where the small imperfections in the tire can be 'matched" in a complementary sense to the small imperfections in the rim. to do this properly, the shop has to be willing to clock the tire on the rim (it may take several iterations) to get the best match.
they will quote you something like 35# of road force is an acceptable residual. it is not.
less than 20# is Mandatory.
less than 10# is ideal.
Also, it is important to go on the rack wheels off the ground within 3 minutes of the car being driven (and not just in from a parking space). You don't want ANY flatspotting messing with the 9700.

nielsn

my guess is that this type of balancing was not done. but I will confirm. funny thing was- I never noticed any vibrations in wheel or through the seat on any roads with old worn shocks, and apparently wheels that were out of balance- but with new shocks, and supposedly balanced wheels/tires I'm noticing vibrations. its kind of a pain, I guess I could also just put the stock audi 18 inch rims with snow tires on the car and see if I get the same issue. I've never had any issues with the stock rims no matter what tire I've had on them.

CarPartsDiscount.com

Sometimes when you raise a vehicle up off the ground to work on it, you unload a lot of components. SOMETIMES this can result in a part seeming like it is going bad when in reality it has been wearing for some time now it just took the movement of being unloaded to show its hand.

For example, i just put new tires on my wife's car. The car has 100k miles on it but showed no signs of any problems. After the tires were installed on the drive home the tires sounded loud. I thought maybe the tires just need to break in? after a few more days of driving the sound got worse and now you could feel it in the pedals and steering wheel. after looking into it one of the front wheel bearings went bad. changed it out, problem gone.

I'm not saying this is your problem, just an example of how working on your car can SOMETIMES lead to other problems due to no ones fault.

saifxnyc

its funny you say that i had koni shocks and eibach lowering kit installed on my car around 95K miles. They made the the car stiffer I could feel every single bump on the road with less comfort and the low profile tires made the car feel like its driving on train tracks literally. The low profile tires were on my car with the stock suspension with rubber band tires it doesn't feel like an audi at all feel like your driving a construction vehicle with the stiffest suspension in the world. The spring and shocks made it worse it makes creaking noises to this day, it will kill you suspension the control arms sway links tie rod etc eventually, they take an extra toll because you changed the way car sits it entire dynamic I am speaking from my personal experience here. There is nothing wrong with your car it just has less room to bounce around so its stiffer and the tires also do not help it. I live in Pittsburgh it was a mistake to lower the suspension I used to travel a lot to the Midwest so I swapped that springs out as a suspension maintenance since I assumed the original shocks were never changed. They never needed changed these shocks can go for a long time ever 150k plus. If you still have stock springs try putting them back in they will give you some comfort back.

nielsn

thank you all so much for the input. well, I did find at least one problem that "might" have been causing some of the vibration. recently, in the past few days, in addition to the vibrations on highway, I began to notice a nasty clanking noise like something was loose and hitting something in the front end. So this weekend I took the right front wheel off and found that my left bolt holding the upper "a-arm" assembly to the top mounts was almost gone and the right bolt wasn't completely tightened. ( at least I think its an a-arm)- its in 2 separate pieces so its not the traditional type of A-arm I'm used to seeing like on a 4X4. Anyway, the left side bolt holding it on top was almost completely backed out- the only reason it didn't completely come out was that the head of the bolt was hitting the body of the car. So the nut was completely gone. My guess is that the shop I had install the shocks must have taken the upper arms off to get better access to springs to replace shocks. dunno, at any rate, they were NOT tightened properly. so I pushed it back in and put a makeshift nut on the end to hold it on and will be taking back tomorrow to have every piece of both the front and rear suspension of the car gone through, tightened, torqued, inspected, re-inspected, certified, blessed by the pope, etc,.... once this is completed I will be re-assessing the road manners and perhaps the wheel/tire combo won't be the issue anymore. we'll see. I am also going to suggest that they take a very close look at all the bushings on the arms and other suspension components, as well as bearings on all connecting pieces. might as well replace all that stuff if its worn while its all be torn apart and looked at. my steering wheel seems to have more slop than when it was new. maybe worn tie rods, dunno. again, I'm going have them REALLY take a close look. Unfortunately, my mechanic was not the one who worked on the car, it was his assistant, who I haven't spoken to about what actually happened. But I will find out for sure. can't have suspension pieces falling off car when its being driven

FL C6.5 Avant

ouch. they should have at least brought to your attention that there were issues (assuming they didn't cause the issue by negligent repair).
so tough to find competent workers.......
You should at least see for yourself while the car is up on the rack (have them escort you if they insist), make them go over everything with your eyes on it as well. If you are not watching for yourself, too easy to report back that they were thorough even if they weren't.