New Wheels Noise/Vibration... help please.
 

I got a set of used Maxxim Ahead Wheels and tires in flawless condition:
Wheels can be seen here:
http://shopping.netsuite.com/s.nl/c....t.A/id.7118/.f

I installed them and took a drive. I notice a shake at 40+MHP and a "Whom, Whom, Whom, Whom" Noise coming from the wheels. The tire pressure is at 35psi all the way around. They're a 42mm offset on the EXACT same rubber that my OEM wheels use. Khumo Ecsta AST

What would cause this? Did I miss something? Do I need some sort of hub centric ring or something?
I figured this would be plug/play.


Evan

Check that you or someone tightened the lugnuts and torqued them to 108 ftlbs...also are they balanced? ...sounds kinda silly but little details can make for some big problem.

Do you think this has anything to do with it?
Check out the fitment of the wheel to the rotor, is this an issue?

if the wheel hub is touching the rotor it should be fine. as mentioned its one of 3 things in this order.
1. need a hubcentric ring.
2. lugnuts not torqued to 108ft/lbs.
3. wheels not balanced.

Agree with nuke on this one but its hard to tell from the picture if the wheel is sitting flush against the hub.

I don't have a torque wrench with me but I went at it again with a 4 way. I was able to get quite a few more turns out of the front tires. The back were pretty snug.
This greatly reduced the vibration and noise.

thats good. now check it with a torque wrench later to be sure.

hub rings

That's next.
How do you know what size to get?

you need to find out what the hub bore is on your wheels, that will be the outside diameter. the RX8 hub is 67.1mm, that will be the inside diameter. the hardest part might be trying to figure out what your wheel's hub bore is.

BTW, if they are the same size you won't need rings, thats easy.

Sounds like the tires may be cupped. I have personally seen that kumho tires like to cup on the inside tread if not rotated often. Run your hands on the inside part of the tread and feel for some wavy tire wear

Hard to tell exactly, but this doesn't look right in the pic. If there is any gap at all between the wheel and the hub anywhere around (can you place a toothpick or a something between them? or just spin the wheel-is it spinning true?) you've got a problem. If the center bore hole is smaller than the wheel hub, the wheel will never sit flat on the hub. Only solution is to have the hole machined larger.

The center bore size (and offset) is the reason you can't just get 'any old wheel' and stick it on 'any old car'! From your 1st post, I'm guessing you got a deal on the wheels from someone.... what car where they used on?

One other thing - I wouldn't "go at it with a 4-way". That's a easy way to strip or break a hub bolt - mucho pain if you do. 108ftlbs isn't very much tightening at all - if you did what you say I'm nearly certain you've way overtightened the nuts.

Go buy yourself a torque wrench. The best advice ever is: Always (Alway!) use the right tool for the job!