Not sure how to change a front wheel bearing? How do you know which is bad? How do you know if it's a wheel bearing noise or a tire noise? I will show you in depth, how to determine if you have a bad one, I will also show you a short video on how to diagnose which needs to be replaced and what it sounds like when it is damaged.
If you have ever tried to diagnose a bad wheel bearing, you know that a wheel bearing sound can travels throughout the car and it is very easy to misdiagnose where the noise is coming from. I just ran into that problem last weekend. While on my road test, I could have sworn the noise was coming from the driver's side. I loaded the driver's side wheel bearing (turning and putting the vehicle weight on that side of the car while driving) and it sounded like the noise was coming from the left front.
After putting the car on a lift and raising it in the air, I used a long screwdriver as a stethoscope. I put the metal tip of the screwdriver on the hub near the wheel bearing, then put my ear on the handle end of the screwdriver and had someone sit in the car and put the car in gear, then bring the wheels up to a speed of about 40mph. If the wheel bearing is bad, you will hear it loud and clear. (See the video for more details) I was fooled once again, much to my surprise, I was wrong; the right front wheel bearing was the culprit, which is why you should never guess at where the noise is coming from.
Once you have figured out which wheel bearing is damaged, it's time to replace it. Almost all wheel bearings in today cars are removed the same way, but I will be using pictures from a 1999 Honda Accord to illustrate the process and walk you through it steps by step. Your objective is to remove the knuckle assembly from the vehicle so you can place it on the press and remove the wheel bearing. This is how the knuckle assembly will look once you removed it from the vehicle.
Step 1. If your vehicle has ABS, the connector is probably routed in to the engine compartment, locate it and disconnect it from the vehicles wire harness and remove all the hold down clips, then feed the wire harness into the wheel well.
Step 2. Remove the caliper assembly and rotor. You may need an impact driver to remove the screws from the rotor.
Step 3. Disconnect the tie rod end, the lower ball joint, and the upper control arm from the knuckle assembly. It is common practice to hit the knuckle assembly with a hammer to release the ball joints from the knuckle where the tapered shaft goes into the casting.
Step 4. Remove the axle nut and remove it from the knuckle assembly
Step 5. Remove the knuckle assembly from the car and prepare it for the press.
Step 6. Set the knuckle assemble on the press and suspend it safely, remove the center hub, starting from the back of the bearing, and only press out the center of the bearing.
Step 7. Flip it over and remove the snap ring or retaining ring from the knuckle assembly. This retaining ring holds the outer race of the bearing in it.
Step 8. Flip it back over and remove the outer race of the wheel bearing.
Step 9. Take the hub assembly and place it in a vice. Using a high speed cutting wheel, cut the inner race that is pressed onto the hub assembly. You only need to cut halfway through the inner race, taking caution not to cut the hub shaft. Using a large chisel, place it in the slice of the inner race and hit it once, it should crack the race, now you can remove it by tapping it off the hub shaft with the hammer and chisel.
Step 10. Clean all metal surfaces with a Scotch-Brite pad or light sand paper. Clean up the snap ring with a wire wheel or sandpaper for easy installation.
Step 11. Reinstall the bearing into the knuckle assembly. Support it on the press; be sure it is level and straight for easy wheel bearing installation. Press the wheel bearing into the knuckle assemble, then install the snap ring.
Step 12. Install the hub into the center race of the bearing. Support the center race of the wheel bearing from underneath so that when you are pressing the hub into the center race, it will not push out the rear center race through the back side of the knuckle assembly. The center race is in two pieces, front and rear, you need to support the rear or it will separate, and possible cause the bearing to be noisy. Be sure the hub bottoms out in the wheel bearing.
Step 13. Reinstall the knuckle assembly into the car in the reverse order, replacing all cotter pins with new ones for easy assembly. Make sure you torque the axle nut and peen it into the notch in the axle, the axle nut holds the wheel bearing together, if it becomes loose, you could damage the wheel bearing.