1997 4WD, How do I tell if the front wheel bearings are bad? I hear a left-side front end noise, and feel some slight vibration as well, when turning at highway speeds, such as exiting from an interstate. It's only there when the wheel is turned slightly and goes away as I straighten the wheel. Any thoughts are appreciated! Thanks, Tom

 

Are you asking about the fornt hub bearings? The ones near the wheel? If yes, as opposed to the bearings at the outer ends of the front axle, then an easy test is to see if when the wheel is off the ground if you can wiggle it when grabbing it on the tread at the 3 and 9 o'clock positions and see if it moves independently of the rest of the front end components. When I had one go out, it was really obvious.

Do you have any odd tire wear?

 

Thanks. I believe the noise might be from the hub bearing, but, I can't rule out the axle bearing. I do get a little bit of wiggle when the wheel is off the ground - it doesn't seem excessive but I don't know what "normal" should be., I do have some inner tire wear on the other front side (right side). Thanks again, Tom

 

I can't find my reference but from what I remember how to measure the looseness requires a dial micrometer and was a value that I did not think I'd be able to feel by hand. Hence my impression that if you can feel wiggle in your hub bearing it is in all likelihood toast. Fortunately, they are not too hard to replace as long as you can get the hub nut off which can be a challenge sometimes.

 

The last two times I've replaced my wheel bearings (and I say it like that because I've replaced wheel bearings 3 times now since I've owned my Blazer :P gotta love oversized tires and offset wheels...), sound was the only thing that lead me on to believing one was bad, and BOTH times I was wrong at guessing which side... Neither had any play or wiggle, I could just hear the growling/roaring starting to get louder as I drove, and that says a lot considering I'm running MT's. You wouldn't think you would hear it over them, but you do, you feel it in the steering wheel and in the floorboard and all.

Anywho, the last two times the only way I found out for sure, I actually pulled the hub bearing assembly completely off the truck and turned it by hand, and could FEEL the bearing grinding inside and could HEAR it clearly grinding.

Granted, it's not the easiest way to diagnose, but it's definitely a sure-fire way to pinpoint or rule them out.




and it's quicker and easier when you have access to a lift and air tools...