Changing front wheel bearings is not a particularly tough job. As long as the race is not scored, the worst part of the job is getting plenty of grease into the bearing. Most of the time, you know that a front wheel bearing is starting fail because of a high pitched whine coming from the front end. This whine is generally not as loud and obnoxious as the brake pad indicator when the brake pads are getting worn.
You will need the new bearing and a small amount of axle grease (the kind that has the consistency of a gel).
Start the job by heading to the auto parts store and buy the replacement bearing. These are not too expensive. Along with the bearing, pick up some axle grease. You can get this in a tube or a can. It is the same stuff. So, it is up to you how to buy it. If you do not have a good supply of rags or shop towels, get some of those, too. The paper kind work alright if you prefer them.
Jack the front wheel off of the ground.
You will need to lift the wheel that will receive the new bearing off of the ground. It is not a bad idea to put a stand under the car on that side for it to rest on. When you are certain that the car is stable, remove the hub cap and the dust cover. The dust cover is the small dome-shaped cap that covers the end of your front axle. The job gets somewhat dirty at this point. You may choose to wear gloves, but most mechanics prefer to be able to feel with their fingers without the gloves in the way.
Make a note of the positioning of the nut that is screwed onto the axle.
When the dust cover is off, you will see a large nut with a pin going through one of the slots along its upper edge. There are usually several holes in the threaded shaft that the nut is on. Count the number of holes before the one that the pin passes through. This is normally the one that you will tighten the nut back to before inserting the pin. This nut is not tight. A pair of channel locks or pliers should do to remove it once you have removed the pin.
Screw the nut off and store it and the pin for later.
When you remove the nut and pin, it is a good idea to store them in the dust cap or hub cap. Grip your tire on each edge and work it back and forth from side to side. You will see the large washer that was behind the nut pop out on the axle. Slide this off and put it with nut and pin. Slide the tire and wheel off of the axle. The bearing should come with it and still be inside the hub on the back of the wheel.
Inspect the axle for damage.
It is rare that the axle will be damaged by the bearing. If it has been driven for a long time with a bad bearing, you may have to replace the axle. Clean the axle so that it will be easy to inspect. Turn your tire and wheel and lay the tire flat on the ground with the back side up. You should be able to look inside and see the old bearing.
Try to pull the bearing out of the hub.
Sometimes the bearing will just slide right out of the hub. If this is not the case, turn the tire over. Use a block of wood or something that is soft enough not to damage any of the metal. Put one end against the upper side of the bearing and tap on the other end with a hammer. Do not try to pound it, but it may take a nice firm hit to jar the bearing from the race. As soon as the bearing falls out, turn the tire over. You should see the bearing on the ground or whatever surface that you are working on.
Look at the bearing and the race.
If there was no damage to the axle, most of the time there will be no damage to the race. Wipe it off until you can inspect it accurately. Check the bearing for signs of wear. You may or may not see this. If it is severe, check out the axle and race again to make sure that you did not miss any damage there.
If the race is in good shape, you are ready to replace the bearing.
Some mechanics will insist on changing the race and bearing together. If you have the tools to press it out, you may want to do this. It will not cause problems if the race is in good shape just to leave it in place. You will get a new race with the new bearing, so the call is yours.
Apply axle grease to the new bearing.
The axle bearing will need to be greased. This is a slow but not difficult task. Scoop up some grease on your fingers and begin to work it into the bearing. It needs to forced around the bearings and inside the casing. When it appears that you can get no additional grease into the bearing, it is time to install it. The exterior and interior.of the bearing should be heavily coated with grease. Push it into the race where the other bearing had been. You do not have to force this.
Once the bearing is in as far as you can push it, you are ready to put the wheel back onto the car.
Carefully slide the wheel back onto the axle. Push it back as far as it will go. Replace the washer and slide it up against the hub. Now, screw the nut back into place. When it is on far enough to reveal the proper hole through the slots on its upper edge, it is far enough. Your tire and wheel should feel tightly in place. Insert the pin back through the slots and hole. Bend its ends to secure it in place. Replace the dust cover and tap it into position so that it is tight. Put the hub cap if you have one, onto the car. Lower the car to the ground. The job should be complete except for cleaning up.
