has it snowed anytime recently in your area? Anytime we get deeper snow here (over 2 inches) my car will start to vibrate from the snow getting in the wheels. If the snow is blowing/drifting and getting into the brakes at all causing the snow to melt, it'll collect on the rims and freeze causing the wheels to go out of balance. Because of the rigidity of the Chassis on this generation of Bonneville, they are very susceptable to this. Mine does it all the time right after a snow.. I've found taking it through the car wash that uses hot water on the wheels takes care of it. (usually)

I would check out the tires and wheel balance before I would replace the bearings.
If it'* not the bearings then you may damage the bearings before you discover the root cause.
I once had a tire that was damaged and the belts inside had started to delaminate unseen but felt as a highway speed vibration.

I've had the tires balance twice, and I've rotated them twice, no difference. Same nasty vibration and harmonizing when I turn to the right. I got the bearing off, I won't tell you how hard it was, but it rhymes with "It was a bitch". Some bolts did NOT want to come. Anyways, I've got the whole hub assemby out, but now I have no idea what to do. I think I'll just take that part to the dealer? It seems to spin ok, but I dunno.....

Is this the same side you curbed?

Honestly, I find diagnosing a bad bearing easier with it on the car and a wheel lugged up.

Jack the car up and try to wobble the wheel in and out (in at top, out at bottom sortof wobble, but rapidly).

Yeah, it is, but I took it to Les Schwab, and they checked the bearing like that, and it was ok. I checked it like that just before I tore it apart, and it still felt tight.

But anyways, I got it all back together, the steering wheel vibration is gone, and so is the wa-wa-wa-wa (for lack of a better word) when I turn, but there is still some pretty bad vibration from somewhere. I'm guessing the rear bear of the same side, cause it hit the curb too.....

I would check for a bent or cracked rim also, especially with this being the side that hit the curb. I also wanted to ask you if you had been able to isolate the problem to front or rear, left or right? Another thing I've seen cause this condition is if someone used either tire balance powder or a leak stop such as "slime" etc. these will change the balance of the tire. does'nt sound like a bearing to me, if it caused that much vibration you would be able to tell right away just jacking up that side and grabing the tire top and bottom and feel the play and hear it when you spun the tire off the ground. occationally you can get a vibration of this type from a bad ball joint or tie rod end, but usually will change alot with steering and load changes. Hope some of this may help, let me know what you found out. good luck! GM-Maine