I have been noticing lately that whenever I am riding I keep hearing a popping noise coming from the front mainly when I turn. I checked the front wheels and there is some play in both of them but not much. A while back I had the front wheels off and I grabbed the axle and I could move it just a hair. Also the brake pads moved with it. I haven't checked that lately but I am thinking that the brake pads are getting wore down and causing there to be more play. Do you think that the bearings need to be replaced? If it is the bearings both sides wouldn't go out at the same time would they?

I did try to tighten the axle nut on one side but could not tighten enough to put the cotter key in a different hole. This is on a 05 rubicon.

What do you think this could be?