Recommendation for a good wheel balance shop?

wstar

Basically every time you take it apart and put it back together, it's likely things will change slightly, but if the vibration's still there after switching brands of spacers it doesn't seem likely the spacers are the issue.

If the tires are the culprit, it should be obvious to a tire person looking at them. The two basic ways tires can be bad that cause vibration are: (1) Some kind of defect or failure in the tire, like a broken belt or tread delamination: if this vibration's been going on for a while, this should be obvious on close inspection, e.g. a single very odd wear area on the tire (like a spot a few inches in diameter on the tire that's worn way more or way less than everything around it), or a bulge in the tread, or some kind of cracking/separation starting to appear near where the main bulk of the tread surface attaches to the sidewalls. (2) Lateral wear from running on bad toe settings (which will persist even after the toe is fixed): should be obvious on a tire-balancing machine. Basically spin up the wheel on the balance machine and stare at the tread grooves. They should run true and straight as it spins; if the groove pattern wobbles, then that's the issue and there's nothing you can do but replace those tires and make sure the alignment's good for the next set.

But you'd think one of these tire balance or alignment shops would've already noticed and told you about something like this. One of those shops should be able to diagnose your car and tell you exactly what's wrong, it seems kinda sad that none of them have done so yet.

Maybe look around locally for recommendations (outside of just the Z community) on a good shop that does both tire balancing and alignment (It can be frustratingly common that many shops only do one or the other (just tires, or just alignment)), and take it to that shop and have them diagnose. Don't go in and tell them "I think X part is bad, can you check that" - have them own the whole problem. Tell them you have a vibration and you want them to figure out what the cause is, whatever it is. They should be able to do it.

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Journal thread / Car setup details

BA9092

Well, yesterday I left my Z at home in the garage and took in my spare (2000 Jetta) to work. I came home and lifted the front end on jackstands again to inspect the tires and wheel. I inspected all the joints, boots, suspension parts and driveshaft u-joints for any play, leaks or tears and found nothing. My suspension guy didn't even bother since he's done an alignment and noticed nothing out of the ordinary in a test drive. He thinks it's either bent wheel(s) or bad/worn tires - especially since I swapped the spacers from a different brand and the vibration still persists.

I did a quick setup with a paint can and the tip of a screw driver to visually check radial and lateral runout of both wheel and tire. I know it's not accurate, but if I could visually detect any difference, then I'm sure a professional measurement would indicate a fault in either wheel or tire.

I spun both tires by hand, one at a time, and noticed the tires were visually off by a millimeter or so, but even several millimeters in radial. It was in both tires, so I think it's just a result of flatspotting from being parked overnight. I would think the Hunter Roadforce machine would flag that down if it were a permanent runout, no?

The outer edge of each wheel were ok. Maybe a hair under a millimeter when I spun them. Would that indicate a bent wheel(s)? I know there is a tolerance of .01 inch by manufacturers, but I guess it would have to be professionally measured to make sure. I thought the Hunter balancer would also detect that though.

I'm debating on getting the wheels inspected and measured for runout by a wheel repair shop before ordering an entire set of new tires.

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Ark | H&R | iSimple | Moweraxle | OnEighty | Osram | RJM I Sylvania I TWM | Wincos | Z1 | ZSpeed

BA9092

One other thing I forgot to mention. The rear whees/tires have never been Roadforce balanced. I know the Z has a pretty stiff chassis from the factory, but do you think any tire or wheel imperfection in either or both of the rear wheels would be able to transfer the vibration to the front of the car through the steering wheel? I do have the same feeling/vibration through the floorboard (not so much in the seats) and deadpedal, so maybe I should get the rear wheels and tires looked at? Anyway, that's what my suspension guy recommended too - to get the rear wheels/tires Roadforce balanced.

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Ark | H&R | iSimple | Moweraxle | OnEighty | Osram | RJM I Sylvania I TWM | Wincos | Z1 | ZSpeed