Wheel vibration
 

I have a set of Avante Garde M310s on the Z and recently noticed some pretty significant vibration in the steering wheel around 40 mph. It happens sporadically, sometimes it is perfectly fine at 40 and sometimes it vibrates. The vibration also varies from slight to significant.

I have driven down specific roads and it almost seems like it happens in the same spots weirdly enough.

I am checking to see if it could be a hub centric ring issue, but also wondered if it could be the tie rod bushings or control arms? The car only has 9k miles on it and is not my daily driver. The only suspension mods include Swift springs which were installed about a year and half ago, and the car is not driven hard.

The wheels/tires were balanced about 6 months ago. My only other thought was flat spotting, but the vibration only happens at certain speeds and the car doesn't sit for more than a few days without being taken for a drive.

Thanks for any help.

Sounds like a botched balancing job. It doesn't have to occur at all speeds, after all. You might be hitting that resonance frequency with the wheels at that specific speed.

The 19x9.5 19x11 setup on the z is hub centric so it can not be a hubring issue.

Just throwing this out there

But have you re-torqued your lugs?

id say mounting and balancing is jacked

Sounds like textbook symptoms of a bent wheel

I haven't, but, I had some new rotors put on and had them hand-tighten the lugs so they wouldn't scratch the wheels when they were put back on. I may have them re-tightened.

I doubt it is a bent wheel, this has only happened fairly recently and I haven't hit anything that would cause the wheel to become damaged. Will a visual inspection of the wheel tell me if it is bent? Looked tonight and everything seems to be good.

The weird thing is that it seems to be sporadic. Only happens around 40 mph, but doesn't happen all the time.

Thanks again for all the advice.