wheel bearing.
easy way to tell. jack the tire up, and watch as the tire comes off the ground. if there is ANY kind of movement of the tire, left to right its shot. other way to tell, jack the wheel up, grab tire at 3 oclock and 9 oclock. wiggle it. is there any play? can you hear a bit of a clunk?
last way, when you pull the hub to do your axle shaft, take the hub off and inspect it. is there any play in it when you spin it? if its good there will be no play in it what so ever.
or if its a ujoint crawl under there and grab the axleshaft; there should be no play. if there is, you have your issue.
if your really unsure you can even bring it by and we can jack it up and take a look. bring beer
welcome to daily driving 33s