Over time, wheel bearings suffer the effects of wear and tear. Water in particular takes its toll on them, making then rust or spoiling the grease that surrounds them.
Wheel bearings allow your wheels to turn smoothly and also support the weight of the vehicle.
If you're noticing alignment problems, your wheels are making a rumbling sound or the steering seems to have too much 'play' then you may have a wheel bearing problem and they may not be doing their job correctly.

The wheel hub connects to the road wheel and contains the wheel bearing. This is a vital component upon which wheels are mounted, your car's smooth running and handling relies on your wheel hubs. Wandering steering, vibration or grinding noises from the wheel when you turn corners indicates that your wheel hubs are in need of a replacement.
Any single component in wheel hubs for any car including the wheel bearings or the hub can prove to be troublesome, especially after 100,000 miles. Don't take chances. Make sure that your car is maintained properly with quality wheel hubs.