May 15 , 2020
Modern vehicles are designed to drive smoothly, even on not-so-perfect road surfaces. Although some vibrations when driving can be normal, if your steering wheel is shaking, something is wrong.
There are many possible sources of a shaking steering wheel. The key to diagnosing the problem is determining when the shaking takes place: during low, medium or high speed driving; when braking, turning or accelerating; or a combination of these actions. If the same vibration occurs under the same circumstances, or worsens, it’s time to get your vehicle to the pros.
Unbalanced tires, warped brake rotors and damaged or worn suspension system parts are the most likely causes for a shaking steering wheel.
Tires and Wheels: Medium- to High-Speed Driving
Tires and wheels must be balanced to prevent vibration. Wheel balancing is the process of equalizing the combined weight of a tire and wheel assembly, allowing it to spin smoothly at high speed.
Tire imbalance results from one section of a tire being heavier than another. That causes the tire and wheel to vibrate up and down or side to side at specific speeds. That vibration typically telescopes up through the steering wheel, causing it to shake. Abnormal tire wear, wheel damage from an impact (hitting a pothole, curb or being involved in an accident), unevenly worn tires or even a patched tire can also cause an imbalance.
Balancing your tires and wheels usually fixes this problem. That involves spinning a tire and wheel assembly using a specialty piece of equipment called a wheel balancer (it’s a job for pros, not DIYs!). Using sophisticated software and sensors, wheel balancers identify a tire’s heavy spots. Wheel weights are added opposite of the heavy area to counteract the imbalance, which eliminates the vibration.
Even new tires usually have some imbalance. Have you ever notice a yellow or red paint dot on new tires? These indicate the lightest point (yellow) or maximum out-of-round (red) on the tire.
Brakes: Any Speed
A warped or damaged disc brake rotor or out-of-round brake drum can cause a steering wheel to shake. A warped disc means the thickness (run-out) across the face of the rotor differs. As the brake pads move over a thinner area of the rotor when stopping, the brake pedal will move up and down. As the thickness variations on the rotor increase with wear, or as the rotors heat up, the pulsations intensify and travel through the suspension system to the steering wheel. Rotors and brake drums can be resurfaced, but if they are worn beyond manufacturer’s specifications they need replacing. It is best to replace both sides at the same time.
Whether you do the brake repairs yourself or leave it to a mechanic, be sure the brake calipers are not binding. Binding calipers cause overheated, scored and cracked rotors. These defects cause vibrations. Always replace all the brake hardware when replacing brake pads.
Suspension Systems: Low- to Medium-Speed Driving
An out-of-alignment suspension system usually will not cause the steering wheel to vibrate. It will cause tires to wear abnormally, however, causing the tires to vibrate. Loose suspension parts (bushings, tie-rod ends, mounting hardware), a worn wheel hub bearing or drive axle CV joint can cause steering wheel vibration, usually at low speed, and likely will be more pronounced when turning into a driveway or when parking.
Other Causes: Any Speed
Snow jammed into the back side of a wheel, road tar or a plastic bag wrapped around a drive axle or drive shaft can cause steering wheel vibration. Wheel weights can also fall off. And stay away from tire sealants. If the sealant doesn’t fully adhere to the inside of the tire, the tire will vibrate. Tire sealants can be extremely difficult to clean out and can ruin a repairable tire or tire pressure monitoring system sensor.
It’s wise to have your repair shop check your tires, wheels, brakes and suspension during recommended maintenance intervals to help avoid future problems.
A shaking steering wheel is most likely caused by a problem that’s only going to get worse. Whether you check your car yourself or take it to a shop, deal with the shaking issue before it causes additional problems with your car.