I had one of my bearings go out, but there wasnt any play in the wheel at all. Just a noise I could hear between 45-55. The race had worn through, and it was just acting up. But when I tried the "jack up and wiggle" approach, no dice.
I also just had this problem and it was a bad motor mount. I thought it was a CV axle, but it was just my entire drivetrain bucking around. What shape are your mounts in?