Weird axle(?) noise

So about (but less) than a year ago, my car started making a bizarre THUMP THUMP sound that was correlated with how fast the tires were spinning; it was the worst when I would make wide left turns. Being in the automotive program I took it into the shop and had the instructor have a look at it and we checked out the underside and there was probably .75 - 1.25" of travel on the passenger side CV axle. He said it was bound to go out soon and I should consider looking at getting it replaced.

Well it was a $350 fix and we wanted to wait because money is tight and it didn't need the fix right away. Last month we had a snow here for the first time in quite some time and we got almost two feet of snow!! Needless to say my car sat parked in the driveway for the whole week and never got turned on.

The following week (after the snow had melted) I started 'er up and went for a drive, expecting the THUMP THUMP that I'd been hearing for almost a year now. Unexpectedly however the thump was gone and was replaced by a low grinding noise which would build in volume as the speed increased. According to passengers they could feel it under their feet as a mild vibration of the floor.

I finally decided it was time to bite the bullet and buy the new axle, so just today I went and got the axle and had it replaced at a local independent shop. HOWEVER they told me (and i checked because i needed to return the core) the old axle boots weren't even split and they thought it was bizarre I asked it to be replaced. On the drive home, the grinding noise was still present!! New axle and everything!

Does anybody have any ideas what could be wrong? I thought we had it pinned down, but I should have known things are never that easy.. :crying: