Pop then grind

[OsideBill]

Did it again today, but this time the grinding noise hasn't gone away. Maybe wheel bearing?

[78F350]

Ok... seriously.
It could be several things. First you need to jack the car up and get a look/feel of the rear suspension. With the wheel off the ground and car safely supported grab on to the wheel at the 12 and 6 o'clock position and try to rock it. Does it rock? -Likely wheel bearing. Grab at the 9 and 3 o'clock and rock it. Does it rock? - Likely trailing arm (control arm) bushings
Next: Check the CV shaft bushings for cracks and loss of grease. Rock the shaft around. It should be able to move in the direction of the shaft axis (smoothly with no grind) it should not have any play perpendicular to the shaft.
Check the bolts that hold the shaft to the transmission (6). On occasion these come loose if not torqued.
If none of that exposed a problem, remove the wheel and take a good look at the brakes for anything loose or rubbing.