Why Does My Car Shake at High Speeds?
While wheels and tires are often the culprits, you may also need to check your suspension and axles.
In a perfect world, your car would sail smoothly down the highway from the day you bring it home from the dealer to the moment you trade it in for the next one. This world isn't perfect, however, and oftentimes your car may shake or vibrate at high speeds. There are a few potential culprits for this sensation, from wheels and tires to axles, ball joints, and tie rods.
High-Speed Shake Is Often Due to Wheel and Tire Imbalance
One of the most common reasons for vehicle shake on the highway involves the wheels and tires. If your wheels are not balanced correctly, you could feel a vibration at higher speeds. The shaking might only be between certain speeds — 50 to 60 mph, for example — but it's important to heed this warning sign.
A bent wheel could also be the cause of high-speed vibration. If you feel a vibration on the highway, consider going into a tire shop for an alignment and to see if you need a new wheel.
Tires with uneven wear or bad tread will also cause vibration, as will rubber that has gotten out of round by sitting for a few months. In these cases, it's generally best to replace your worn tires.
Ball Joints and Tie-Rod Ends Can Also Be Culprits
If just the front end of your vehicle feels shaky, it can be worthwhile to check your ball joints. Should the vibration be accompanied by a wandering steering wheel or a clunking sound from the front, the problem is likely in this critical suspension component. If you've had your car aligned and it's still vibrating at higher speeds, the ends of your tie rods might be worn out.
You should also consider checking the suspension bushings, nuts, and bolts. Everything should be tight and free from wear. A bad wheel bearing will likely manifest as a grinding sound but may also make the car shake at lower speeds, moving into a humming sound as you go faster.
An Axle Issue May Also Be to Blame
A bent axle caused by driving over a bad pothole or similar is another potential cause of your car's vibration, especially if that vibration gets worse the faster you go. If a constant velocity, or CV, joint is worn or if a CV boot gets torn or damaged and dirt gets into the joints, a vibration may result.
Finally, a bent driveshaft can also make you feel like you're driving through mud. The driveshaft transmits the power from the transmission to either the front or rear wheels. If it's bent, you'll feel it. In all of these cases, the only solution is to replace the worn or bent part.
A shaking car is a serious problem that you shouldn't ignore. The solution may be as easy as a simple alignment or as complicated as a driveshaft replacement. Regardless, it's usually safest to take care of the issue as soon as possible.