videsi

thanks all. my plan is to escalate this with AofA, and go to an independent tire shop to get the wheels balanced one last time myself. to prove to the dealer that my car indeed has an issue, i recorded the vibrations on the passenger seat-back using my phone accelerometers. then i did an FFT to clearly show vibrations peaks at 5, 10, and 15Hz. i then took the same data on my other car (370Z) on the same roads, same speed (71-74MPH) and same weather conditions. it's clear from the attached plots that the A4 has a vibration issue. i've sent this to the dealer service manager.

Bob Petruska

and if so, do they really know how to use it? I'm talking about where you measure the rim and tire characteristics and unmount the tire and place it in the correct position where the LF balancer want's it?

I have had all mu tires balanced with the LF balancer this way over 10 years and I have forgot what an unbalanced tire feels like at any speed, my tires/wheels ride as smooth as glass.

snagitseven

Bob - a couple of minor clarifications: it's road force balancing and the tires are not dismounted - the tire bead is disengaged from the wheel while still mounted. The Hunter balancing machine computer measures the road force in pounds and will indicate to the operator where the least amount of road force will be by rotating or "matching" the tire to the rim.

The operator does the road force balance test, and if matching is needed, marks the tire and wheel as indicated by the machine's computer, lets the air out of the tire, pops the tire bead from the wheel, turns it on the wheel to match the marks, fills it back up and retests. Audi claims a wheel/tire is in spec if the road force is 20 lbs or less. If a tire/wheel combo cannot be force balanced to at least that spec, vibrations are virtually guaranteed. (The tire is usually the culprit if it can't be force balanced under 20 lbs).

Lots of good info and videos here:
http://www.hunter.com

Note that most, if not all, Audi service depts. these days, have a Hunter force balancing machine. Any good dedicated tire shop shop will also have one. Typically, force balancing runs about $25-$35 per wheel, roughly double that of a standard high speed balance.

videsi

both dealerships that i went to used the road force balancing machine and found every time one or the other tire to be out of balance and said they "fixed" it. however, the vibration characteristics of the car haven't changed at all even after 5-6 road force balances, so i have no faith in anything they do at this point. very close to filing lemon law.

snagitseven

As previously mentioned, balancing is only a part of the story. You were given advice to swap the front wheels/tires with the rears. Did you try that? Also as suggested, did you take the car to a wheel straightener specialist to see if any of the wheels were bent or out of round?

Flopinator2000

I had the same problem on my 2010, with tires from a 2013 A4. I had them road force balanced at 3 different shops, finally just went to the dealer because after having new tires and rims and them balanced so many times, i figured a bad wheel bearing or something was bent. Nope, the dealer did the balancing over and told me that it not done correctly, they never force matched the tires to the rims, they just did a balance and never moved the tires. I can now drive over 65mph, where as before the road force the car was so bad i would not go over 65mph. So make sure whoever is doing the balancing....knows how to do it! Dealer charged me $270, but well worth it for a perfect ride

jagtoes

I would go back to the dealer and take the service manager for a ride and demonstrate what you feel. Then ask/tell him you want a set of wheels/tires taken off another car in the lot and then go for the ride again. If the vibration is gone then you need to get a replacement set of wheels and tires. If you still have the vibration then you have a drive train problem. The next step should be in the dealers hands.

mjdc18

So, just got a brand new 2013 A4 yesterday, September 25. As soon as speeded up on the Interstate, noticed strong vibration in the steering wheel and vacant passenger seat. Per what I've read, I think my nightmare has just begun.

snagitseven

Well, since the car is brand new, it's probably not a bent wheel. While it could be a defective tire or something else, more than likely a wheel or two need to be balanced. Don't get ahead of it yet. Occam's Razor says the simplest answer is often the correct one.

gunsmoker

I get vibrations on newly paved highways. They go away after some time. Not sure if it has to do with the tires or other. I'm putting new tires on next week and there is a fairly new stretch on I95 around Norwood, MA...