I have been a mechanic all my life and I have worked on everything from fancy cars to big class 8 road trucks and everything in between, when someone asked how do you tell if a wheel bearing is going bad, I think of all the thousands of wheel bearings and races I have installed over the many years of working on vechicles. If your going down the hwyway and you hear a rumble and you feel shaking in the steering wheel and then you see your wheel pass you by you have a bad wheel bearing, Don't laugh at this, IT DOES HAPPEN. But it doesn't have to happen, now my next question is why do most people like these forums, most people read to learn, and and there is no such thing as a stupid question, My reason is I have been a mechanic all my life and there isn't a day that goes by that I don't learn something new, somebody always has a better way to do something. THE ONLY WAY TO CHECK A WHEEL BEARING IS TO REMOVE THE WHEEL AND REMOVE THE HUB AND THE REMOVE HUB SEAL AND THEN REMOVE THE BEARINGS AND WASH THEM IN A PARTS CLEANER AND VISUALY CHECK THE BEARINGS FOR WEAR, if they are worn you will see pits and discoloration on races and bearing rollers, now after inspecting the bearings you find nothing wrong you do need to repack the bearings properly if you don't know how to do this then I suggest you buy a bearing packer or learn to do it with the palm of your hand, there is a right way and a wrong way. Now if I had 85.000 miles on my car I would just invest in brand new wheel bearings they come with races and are fairly . cheap. so if you want to learn do it yourself if not take it to a shop it.s called Maintenance. Jerry, Master Certified ASE Mechanic