Not a huge commenter here but since I have/had this problem I wanted to assist.
Ordered a 19x8.5 wheel and tire kit from AM almost a year ago, upgrading from 18s. The wheels weren't balanced properly from the start, and I went to five different shops in two states for balancing. None of them could get it done. The vibration was both in the steering wheel and the body. Thought it might be bad LCA bushings (read this online, might be possible for you) so I replaced the LCAs as a whole and still had vibration. You might want to replace the bushings anyway because mine were already cracked.
Actually I'm gonna skip over the part where I had to go through a grand total of 11 of these wheels. It was a literal nightmare. But I wasn't the only one who took a financial loss, since AM sent most of the new wheels to me for free.
Overall, two of the wheels were determined defective, so you'll want to take it somewhere that can tell you if a wheel is bent. At one of the many trips to the dealer, I asked for them to check if my balljoints/tie rods needed replacing. Those checked out fine, but they told me (FINALLY) that I had a bad tire in the front right. So they rotated my tires as normal and viola - the steering wheel vibration was gone. Even after replacing the bad tire, the driveline vibration still persists. I had to confirm that buying a new tire accomplished something, so I re-rotated my tires just to see if the steering wheel would vibrate again (which would indicate that one wheel/tire was still off). Everything pretty much checked out.
So now, since its only driveline vibration, I'm about to swap out my driveshaft for a one piece aluminum because I suspect a bad u-joint or center bearing. I actually tried to do this today but sadly lacked the necessary tools.
Feels like I wrote a jumbled mess so sorry. It's just really bizarre because the wheels and tires are completely fine now. It's like putting them on my car also caused the driveshaft to go bad. Here's the short version:
- if you have steering vibration, rotate your tires (individually, if you can) to pinpoint the issue
- get balljoints and tie rods inspected
- wheels can be bent
- tires can be defective. Didn't think it was something I'd ever experience but I did
- LCA bushings cause driveline vibration for some people, didn't change anything for me
- if you put the old wheels on and there's suddenly a vibration, I'd suggest some driveshaft work
2010 Red Candy GT - So Far: Airaid Race CAI + BAMA Tune, Pypes Violator Axle-backs, Daytime Running Lamp Turn Signal Module, GT/CS Spoiler, Hood Scoop