sbmellen

First off: '98.5 A4 2.8 QMS is the car. 108,000 are the miles.

I had major cupping of my previous tires on the inside of the tread, the front suspension being the culprit. I surmised this because when I rotated the tires from front to rear, the same happened to the rotated tires once they were on the fronts, for a time (8,000 miles).

I then surmised (from what I've read), that this meant a poor suspension, including bad shocks. Since I had new lower control arms (less than 2 years old) and tie-rods, I thought to replace the entire shocks around the car from a local German auto indy shop. DONE. Got new Bilsteins on all 4 corners and aligned.

Then, got new tires on all 4 corners within the same week. Got 225/50 16's Kumhos, balanced and installed on Friday.

Now, this weekend, when traveling long-distance on the new shocks and tires, I still get a pretty noticiable vibration through the steering wheel above 85 MPH, especially between 85 and 100.

My fear is that the reason that my previous tires were "cupping" or scalloping was something above and beyond: a) new shocks; b) a new alignment; c) new tires & balancing.

Any thoughts as to why I'm still feeling some significant vibration on new tires/shocks/suspension at these speeds? Could the wheels/tires have not been balanced correctly at Discount Tire?

Any insight would be greatly appreciated. Thanks!

bitjockey (bum)

TREs, probably.

sbmellen

Replace them (again) or have another shop, maybe the dealer [gasp!] look at 'em?

I mean, who's going to take my car up to 100 MPH on local freeways to check for vibration?

jprice@CPS

Did you get a proper 4 wheel alignment after TRE install?

ThirdEye

Make sure the rims have hubcentric rings installed

kenny (dremel)

Make sure they actually TEST it at high speeds too. Lots of shops say "yeah sure we've got one" and they don't actually high-speed balance them.

Friend had a similar issue on his truck. Had the dealer check every part top to bottom, took it to 3 different tire places, finally the last place balanced it at high speed properly and he hasn't had a problem since.

MIKOSB5

do the optimize balance which they will rebalance it with 10th of an ounce request for the best tech in the shop. Make sure they install the hub centric just what thirdeye said. Question: is it vibrating when you go above 85mph just cruising or when you hit the brakes above 85mph? If it vibrates hitting the brakes then it's brake issue. if it vibrates when you are just cruising it should be just the balance since you have replaced most of the suspension parts.

rabbid

Hey,
I also run a Miata as my summer car - this car is very sensitive to tire/wheel balance.

The only way I could get the vibration killed was to find a shop that used a Hunter RoadForce balancer. This tool does a significantly better job then the average balancer.

Also helps to request a precision balance, and to slip the tech that does the work a six pack of micro brew.