How to diagnose which wheel has the bad wheel bearing
As a wheel bearing wears it begins to make noise. Finding the bad wheel bearing can be challenging. The noise is caused by pits in the bearing race that cause a slight knocking or growling noise. The noise changes as you drive on a straight flat road and make slight changes to the steering wheel.
But it can be difficult to detect a wheel bearing noise on some front wheel drive vehicles equipped with double ball sealed bearings. That’s because pits on the outer race may only make noise under certain stressful conditions. Keep in mind that bearings only make noise when they’re under load, so if you jack up the vehicle and turn the wheel with no load, it may not make noise. But there are still tests you can perform to locate a bad wheel bearing
• With the vehicle jack up and wheels off the ground, touch the coil spring while rotating the tire. Compare the feel of the vibrations on the spring from one side to the other. The spring with the greatest vibration will be the wheel with the worn bearing.
• Place your hands on the tire at the 9:00 and 3:00 positions and wiggle the tire in and out to check for play. Repeat with your hands at 12:00 and 6:00. The wheel with the most play will be the one with the bad bearing.
• While driving, rock the vehicle from side to side at low speeds by turning the steering wheel. This changes the load on the bearings which causes the pitted race to make more noise when under load.
Deciphering wheel bearing sounds
• Snapping, clicking or popping when cornering or in turns—this isn’t usually the symptom of a failed wheel bearing. It’s more likely the sound of a failing outer CV joint.
• Grinding when the vehicle is in motion—almost always the sign of a damaged roller or bearing race. Character of the noise changes during a turn or when the load shifts.
• Knocking or clunking—also not normally a symptom of a failed wheel bearing but more likely a failing CV or U-joint. It can also be a sign of excessive backlash in the differential gears. .
• Humming, rumbling or growling—a worn wheel bearing may hum or growl when driving the vehicle in a straight line and the sound intensifies when you turn the wheel because it changes the load on the bearing. However, these same noises can also be symptoms of tire or drivetrain components.
• Wheel vibration and/or wobble—usually not the sign of a worn wheel bearing until it was preceded by the symptoms listed above. In order for a wheel bearing to causing vibration or wobble it would have to be severely worn and the driver would have had to ignore all the preceding warning signs.
©, 2016 Rick MuscoplatPosted on by Rick Muscoplat