Knocking or grinding sounds, wheel vibration or pulling to one side when braking are all common signs of a worn rear wheel bearing that may need replacement. A grating sound that worsens on acceleration is also an indication of a bearing issue. Correctly identifying the problem and taking prompt action can ensure that more extensive damage does not occur.
A grinding noise occurring when the vehicle is in motion typically indicates mechanical damage within the wheel-end systems possibly related to the bearing. Grinding noises often present themselves when turning or changing speeds create a shift in load. Humming, growling or rubbing sounds that are present when driving in a straight line and that intensify when the vehicle is turning often indicate a wheel bearing issue on the opposite side of the vehicle from where the sound is emanating from.
A vibration or wobble may indicate a lost clamp or a bearing that has suffered extreme wear or mechanical damage. Loose or faulty bearings can also lead to an abnormal side-pull when applying the vehicle's brakes. Rear bearings that are loose, faulty or have suffered from damage may produce uneven wear of tire tread. Uneven brake pad or rotor wear is another potential indication that rear bearings may require replacement.