The topic of reducing car and wheel vibration came up on old topic about wheels and axles. I thought it was some great points and insight into some modding techniques so I'm migrating some of that info here since it's kind of buried up on the other thread.
Some content taken from Axles and wheels modding posted by Go_Time.
Vibration and wobble is a speed killer. That we know.
Member Chrisw asked about what he can do to reduce the vibration that always seems to come along when you fix the axles in your car. No matter whether you're doing a straight wheel swap or if you're using axle tubes, sometimes the wheels always wobble, causing vibration.
I always notice the loudness of cars, or lack there of. I've learned that the quieter the car, the faster it is. And I knew that meant it had better wheels/axles but didn't really think to hard what I could do to fix that problem. I always just wrote it off as "that's the way it is" and I just pulled from a bad car. Of course, I also felt that I could test a ton of cars looking for quiet wheels and would never find them. It was nirvana. And call me lazy, but I don't have the patience (or desire) to go through car after car looking for them.
But a few members, including League of Speed, had some insight on what creates the vibrations and how to go about trying to reduce it.
From League of Speed:
The diameter of the axle is usually not the issue. Now there can be a bur near the axle head sometimes that will inhibit good wheel spin and light sanding can help, but be careful if there nickel platted though - don't sand off the platting - but 99.9% of the time it's the inner wheel hub after production. It can be egg shaped, oval shaped and that causes crappy wheel spin aka wobble or vibration. Also, when the axle is set in the chassis it usually intensifies the hub flaw, and all it takes is one bad wheel out of 4 to effect speed and perfomance.
It's one of those obvious things that you don't think about until you start chasing the dragon. I've gone down the route of (trying to) de-bur the axle and even sanding the wheels, but it never struck me to consider the wheel hub (wheel hole) as the bigger culprit...but of course!
The wheels are mass produced like everything else on the car so that hole isn't going to be the same every time...probably never, actually.
And then in my case where I glue down the axles as a general practice, that can end up making that wobble worse...so maybe since I'm not diligent enough with my wheel holes, I shouldn't be fixing my axles at all? Hmmmm...
Share your tactics and trials with improving your wheels and axles to reduce vibration. Do you drill out the wheel holes so you feel they're all uniform and likely more round? Do you try to sand that tiny hole?