Originally Posted by cbechtle

It was screwed up wheel stagger...took it back to Discount tire...they mistakenly put rear tires all around and put one of the rear wheels on the left front...

I'm an idiot for not checking their work...

I had the wheels and tires put to the proper places and wouldn't you know it, the problem has gone away. I need to get another alignment, but the sound is gone and all seems better in the world...

Thanks for all the suggestions, especially the bushings. I'll be replacing them next.