- Do It Yourself Auto Repair
How to Diagnose Bad Wheel Bearings
Unless your car has been maintained or was parked for many years, there is a good chance the wheel bearings in the axles may be going bad or are. What happens is, inside a wheel bearing there are several small "balls" that turn the bearing to make it move freely. The symptoms of wheel bearing problems/failure is you will hear a popping sound or clicking sound as if something is rubbing against something. The sound will be more pronounced the faster you go. Its like a "thump, thump, thump" . Do not mistake this for a U joint problem, that makes a clicking noise when you are turning full left or right. A more common symptom is a whining or humming sound that is fairly constant and increases with higher speeds. If you have a metallic noise or clanking similar to keys on a chain, dull sounding, many have traced it to bushings that need to be replaced, not wheel bearings.
One way to check if it’s a wheel bearing is to get up to the speed that you hear the noise, then swerve left and then right (should be done in an empty parking lot), if you swerve left and you heard the noise louder on the right side then the right, it’s a faulty wheel bearing, and same goes as if you go right and then the noise is louder on the left, then you need to determine if it’s the front or the rear. Another way is to jack up the car, hold the suspect wheel and determine if you can move the wheel left or right, up or down, if you can, the bearings are failing (lack of grease). If you jack up the car one quarter inch above the ground, the wheel will spin freely. Listen for any whirring or metallic sounds.
Symptoms of worn U-joints include clunking when you put the vehicle in gear, or vibration that matches transmission output speeds. At best, a worn U-joint causes vibration and clunky operation. At worst, a suddenly broken U-joint can cause an accident.