Loud grinding noise

I have a 2003 2.2FWD Vue and last week the grinding began/brakes shaking. I had a rt/rr tire that was low checked it out and seen it had a couple of big screws in it, replaced rear tires figuring this would eliminate the noise. didn't fix it. Next figuring maybe there is a brake issue bad wheel cylinder or something. First, harder than heel to remove drums.... I've never had this kind of problem before is this normal? ebrake seems to grab and release ok. cylinders look ok pads look good? is it the bearings? Where the sound is coming from the rear and when I roll all the windows down I can't hear it isolated or louder in any certain direction. How can I tell which one maybe bad?

Help!

Is the noise evident only while braking, or only under certain conditions?

I would check my hubs to see if a bearing is bad.