Unlike rear-wheel roller bearings which are sealed, the front wheel of a car with conventional rear wheel drive uses tapered roller bearings. Tapered roller bearings consist of four parts, the outer cup or race that is pressed into the brake drum or disk, the cage which holds the rollers and the inner race. When assembled, the rollers run on the tapers of the races.
There are two bearings per wheel, one on the inside, the other on the outside; together the bearing pair supports the brake drum or disc and the wheel with tire. If one fails, the mechanic that undertakes the tapered roller bearing installation should always replace the bearings on both wheels even though they may appear OK.
Inspection before replace:
The first thing that must be done is to elevate the car off the ground. When both rear wheels are off the ground they both will rotate so chock the wheel on the opposite side to where you think the faulty bearing is. Grab hold of the wheel at the top and bottom and give it a good shake, then spin the wheel to feel if it runs smooth or not. Anything more than a few millimeters of play suggests a closer look.
Remove the wheel and the brake caliper; it’s always a good idea to support the caliper so it does not rely on the brake hose for support. Remove the brake disc from the spindle and inspect the bearings. If there is no evidence of scoring on the races, the rollers appear to be in good condition and there is no evidence of the bearing having been overheated chances are all you have to do is pack the bearings with grease and put the wheel and caliper back together.
If however, there is evidence of wear new tapered roller bearing installation is required, this is often a job for a skilled mechanic. Visit website to know more.