im not really good at these things just a question.. how do i know when they need to be replaced? what signs or noises do i need to look out for? im at 99458 miles and lately when my car goes over rough roads it makes noise at all four corners like if something was loose, could this be a hint?

 

Bad wheel bearing usually sound like the noise Semi-truck tires make.

You can also test by jacking up the car placing one hand on 12 o'clock and another on 6 clock. Pull the 12 o'clock hand and push on the 6 o'clock hand. If you feel play then it's a high possibility your wheel bearing are on their way out.

 

and the bad news is if that is the problem you can't replace em- you have to buy a whole new hub.

 

When a wheel bearing went bad on my Audi, it sounded like an airplane was flying a few feet overhead. It was just as bad on smooth roads as rough ones.

 

when you have bad wheel bearings, it sounds like there's a hole in the exhaust. I think your struts/shocks are dead...

 

When the wheel bearings went out on my Buick it sounded like there was an abnoxisly loud honda next to me LOL

 

Wheel bearings don't all wear the same, so they don't all sound the same, but it's usually relatively easy to nail down. I don't think they cost that much on the IS, the good thing about needing to replace the entire hub and bearing assembly is that you don't need a press to do it, so it's relatively easy to do.

Jeff