steering wheel shaking

This has been a problem for a few months now. I just got new front tires on my SL2. I had them balanced but the mechanics said that the alignment was good. When i am going down the freeway around 75-80mph there is a tremendous shaking in the steering wheel? What could this be and how can i fix it? thanks

any difference accelerating/braking/crusing?

the tires may not be balanced right, the alignment may be off. CV joints may be unbalanced(rare). wheel bearing may be bad.

theres a little slipping when i break but it happens right when im about to come to a stop. other than that everything is fine.

may also be bad brakes, but the above is more likey i think.

if u turn the steering wheel to either direction and the shaking gets worse, then its most likely a wheel bearing...the same thing happened to my best friend's saturn...but it would kind of shake at around 35 on up, but there would be like a "thump thump thump" sound when he was goin straight...

My friend told me that something with my steering column could be stripped or loose...is this true? I still havent had time to take my car in to be balanced and aligned. But before i do that i want to make sure its not something big.

i just got my tires balanced. The shaking is not nearly as bad but it still does it when im going 75+ on the freeway. What should i do next?

still a handfull of things, but according to this niffty chart i have, it may be tire &/or wheel lateral runout. gotta have a shop to check to see if the wheel is true. i imagine unbalanced tires, if ignored long enough, could effect runout. i think i'm going to post this chart....