Wheel bearings are important elements of a vehicle’s mechanism. They not only carry the car’s weight, they also make it possible for the wheels to spin freely and without interference. The first most people know about having problems with their wheel bearings is a rubbing sound while driving in a straight line. Typically, the noise becomes louder as speed increases and reduces in volume as the vehicle slows down or turns. They may include humming, squeaking and/ or growling sounds.
Determining whether a problem exists may be fairly easy if the noise is quite bad and can actually be heard over other noises within the car, like in this example of a bad wheel bearing noise problem. Occasionally, or rather, if the problem is just beginning to set in, it may be necessary to wind down the windows, turn off the radio and listen carefully. In this second example of wheel bearing noise, for instance, it would possibly be necessary to do this.
Another method of detecting issues with wheel bearings is to jack the rear end of the vehicle up (placing wood blocks or chucks in front of the front wheels to stop the car moving), then grasping each rear wheel in turn and rotating it while listening for rattling, grinding or growling sounds. If these sounds are present, or if the movement feels rough, there is likely to be a problem.
Next, the wheels should be grasped firmly and shaken gently. On shaking the wheels in this manner, there should be no more give, or movement) than a small fraction of just an inch. If there is more play, there is a good chance of the wheel bearing being defective/ worn and need to be replaced. The same procedure should then be repeated for the front wheels.
Consequences of bad Wheel Bearings
Bad rear wheel bearings may affect the steering of a vehicle. This may manifest itself through a ‘wobble’ in the steering wheel or imbalanced steering. Occasionally, a car may, for example, pull slightly to one side even though the steering wheel is held to go in a straight line (although this may also be a sign of other issues, like uneven tracking, and so on).
If the bearing problem is not fixed as soon as possible, it may eventually lead to the wheel bearing collapsing or seizing unto the spindle. Either of these instances will subsequently lead to the wheel being completely unable to spin. This can be particularly dangerous if the front bearings of FWD vehicles seize up in this fashion. Such an problem may not only cause additional problems as the engine is still trying to move the wheel, but could also cause serious accidents as the vehicle suddenly swerves to one side.
In any case, leaving a bad wheel bearing to deteriorate further usually ends up in repair costs increasing significantly. It is therefore advisable under all circumstances to fix issues, or get them fixed, as soon as problems are detected.
How to Fix Wheel Bearing Issues
In order to replace defective/ worn wheel bearings, it is necessary to have a jack, as well as jack stands and, of course, wood blocks or chucks.
It should be noted here that individuals with little or no knowledge of car repairs may be better served asking a professional to perform the repair. This also applies to individuals who may not have the physical strength to perform the necessary work.
If you feel confident that you will be able to undertake this type of repair work, you can replace wheel bearings as follows.
To begin with, the vehicle should be parked on level ground. The end of the vehicle requiring work should then be jacked up, and for safety purposes, a jack stand should then be placed underneath the raised end. The wheels still touching the ground should then be stopped from moving with the help of wood blocks or chocks. Following this, the tire of the wheel to be worked on should be removed. Next, the bearing cap needs removing. This is followed by pulling out the cotter key and its retaining ring with the help of channel lock pliers. The spindle nut has to be removed next, after which the outer wheel bearing can be removed and inspected for damage.
The rotor should then be pulled off the spindle. After this, the inner bearing, gaskets, and so on, are removed, again inspecting all parts for damage. Using an old rag, all grease should then be carefully removed.
Having done this, the races need to be removed from the hub (it should be noted here that the races must be kept perfectly straight while pulling them off. This will help to prevent binding, which makes it more difficult to remove them). The spindle and races then need to be cleaned carefully. This should be followed by putting clean grease onto the first of the bearing races. The whole process should then be repeated for the second race. Races should then be placed back onto the spindle, ensuring they are straight and seated fully and correctly on spindle. The bearings then must be packed with fresh grease. Once this has been done, the inner wheel bearing must be set into position on top of the prepared greased race.
Next, it is time to position the seal again (please note that both bearing and seal should lie perfectly flat). Then the rotor must be positioned onto the spindle. It should sit flush against both seal and race. Following this, the outer bearing needs to be set back onto the spindle and topped with a washer, followed by the spindle nut being lined up correctly and tightened by hand. After giving the wheel a spin, the nut should be re-tightened (1/4 turn using a wrench should be sufficient). A new cotter key should then be inserted into the spindle, opening the prongs to prevent it slipping out. After greasing the inside of the hub and tapping it back into place, the tire can be replaced, followed by lowering the car.
Please note that the grease used to do this work must be kept clean and free of any dust, dirt or grit at all times. A video showing the wheel bearing replacement procedure in full detail can be found on YouTube. Alternatively, you may wish to take a look at this walk-through for the replacement of rear wheel bearings (complete with pictures).