A bent hub will cause a severe shake in the steering wheel, not noise. A noisy wheel bearing will sound like an airplane engine. With the older pressed-in bearings you could tell which one was bad by turning slightly such as when changing lanes on the highway. Your car uses a bolt-on type bearing. They are quite a bit more expensive but a lot easier to replace. The problem is though there is no way to know for sure which one is noisy just by driving the car. It could sound like the noise is coming from the right wheel area, and it might even get louder when turning slightly to the left, (putting more weight on the right bearing), but it could still be the left bearing. The good news is if you replace the wrong one, you can put the old one on the other side.
The only way to know for sure which bearing is noisy is to run the car in gear with it jacked up off the ground, and listen next to each one with a stethoscope. It will be real obvious when you listen to the noisy one, but you won't hear it when just standing next to the wheel because there isn't any weight on it.
Replacement is easier if you have the service manual. Remove the wheel, brake caliper, (don't let it hang by the rubber hose), and rotor. Remove the axle nut, then the bearing is held on with three or four bolts behind the spindle. The most important thing to remember is when installing the new bearing, the axle nut MUST be torqued to specs with a click-type torque wrench before the car's weight is put on it. Some people hold the axle from turning, so they can torque the nut, by installing the wheel and setting the car on the ground. Putting any weight on the new bearing without first having the axle nut torqued will instantly make it noisy. Holding the axle from turning is real easy by just sticking a large screwdriver through the vent slots in the rotor. That can even be done after the brake caliper is installed.
While you have it all apart, put a light coating of special high-temperature brake grease on the hub where it contacts the rotor. Caliper mounting points should be coated lightly too. Do not use any type of anti-seize compound on the lug nut studs. If the studs are silver or a silver-bluish color, they are anodized and no grease should be used on them. If you do use any grease on the studs, run the nuts on by hand, then torque them to the specified value, usually 95 foot-pounds. Air tools will spin the nuts so fast that grease will be whipped around onto the contact surface where the nut touches the wheel. That contact surface must be kept dry to prevent the nut from loosening.
Don't get any grease on the rotor or brake pads. It will soak in when they get hot from normal braking and cause a squeal. It is acceptable to wash any grease off with brake parts cleaner before driving the car.
Friday, January 21st, 2011 AT 7:15 PM