Read the guide: Why your car vibrates at 60 mph
How to test steering wheel vibration
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Step 1: Find your tire size on the tire sidewall or the sticker inside the driver's door frame, for example 225/65R17. Not sure? Choose Typical car.
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Step 2: Agree on the speed where the steering wheel shakes most, such as 65 mph. The driver holds that speed on a straight, smooth road where it's legal and safe.
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Step 3: As the passenger, enter the speed and tire size, then tick I'm a passenger.
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Step 4: Sitting back with your seat belt on, hold the phone flat, screen up, on the dashboard as far toward the steering column as you can reach without leaning or crossing into the driver's space, and never over an airbag cover. Tap Start, and on iPhone tap Allow.
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Step 5: Keep your hand still for the 30-second measurement. It starts as soon as you tap Start.
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Step 6: Measure again about 10 mph slower, where the wheel feels calm, and compare the two results.
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Step 7: Run the car vibration test with the phone on the center console at the same speed. If the shake is clearly stronger near the steering column, the front wheels are the likely source.
What your result means
Your result lands on one of four levels. This page uses the machines and appliances scale, which is based on RMS velocity in millimeters per second (mm/s).
| Level | Range (RMS velocity) | What to do |
|---|---|---|
| Smooth | Under 0.71 mm/s under 0.028 in/s | Little shake reaches the dashboard. Your hands may still feel some through the wheel, so test again at the exact speed where it's worst. |
| Normal | 0.71 to 1.8 mm/s 0.028 to 0.071 in/s | A mild shake, common on rough roads. If it only shows up in one speed band, a front wheel balance is a good first step. |
| Rough, check it | 1.8 to 4.5 mm/s 0.071 to 0.177 in/s | A clear shake. Many cars read this high on ordinary roads, so compare with the calm-speed run: if this speed reads clearly higher and the frequency matches your wheels, have the front wheels balanced and the tires and steering parts checked. |
| Too much vibration | 4.5 mm/s or more 0.177 in/s or more | A strong shake. If it's much higher than your calm-speed run, slow down, skip long trips and get the car inspected soon. If it started suddenly, pull over safely and check for a bulging tire or loose wheel nuts. |
What steering wheel vibration at speed tells you
Steering wheel vibration that builds at highway speed and fades again as you go faster is the classic sign of a front wheel out of balance. This tool checks that idea with numbers. It compares the main frequency with how fast your wheels turn at the speed you entered. At 65 mph, a 225/65R17 tire turns about 12.8 times a second (766 RPM).
- Within about 10% of the wheel frequency: likely a wheel or tire problem, such as balance, a bent rim or tire damage.
- About twice the wheel frequency: possibly a tire that’s out of round.
- No match: it could be the driveshaft, an axle or the engine, which often turn faster than a phone can measure.
A steering wheel that shakes usually means the front wheels. If you feel it more in the seat and floor, the rear wheels are more likely.
Common causes and fixes
- Front wheel imbalance. The most common cause of a steering wheel shaking at high speed. Fix: balance the front wheels, or all four.
- Bent rim or out-of-round tire, often after a pothole. Ask for a road force balance, which finds high spots a normal balancer misses. A bent rim may need repair or replacing.
- Tire wear and damage. Cupped or scalloped tread can shake and hum. A sidewall bulge means a broken belt inside the tire: replace it now.
- Worn steering and suspension parts, such as tie rod ends, ball joints and control arm bushings. They rarely start a shake alone, but they let a small one grow. Signs: clunks over bumps and steering that feels loose or wanders.
- Brake rotors. A shake only when braking points here.
- Wheel bearings. A bad bearing usually hums or growls with speed more than it shakes.
- Solid-axle trucks and Jeeps. A violent shake after a bump, often called death wobble, is a steering and suspension problem. Slow down smoothly until it stops, then get the front end inspected before driving far.
Get the car checked by a mechanic soon if the shake is new, getting worse, or comes with clunks, pulling or loose steering. Steering problems are safety problems.
What this tool can’t measure
- The shake at the rim of the wheel. The phone sits on the dashboard, which moves less than the wheel in your hands. Your reading may be lower than what you feel.
- Which front wheel is at fault. Both turn at about the same rate.
- Anything faster than about 30 Hz. You’ll then see “The main vibration may be faster than your phone can measure.”
- Worn parts you can’t feel while driving. Play in tie rods and ball joints shows up when a mechanic lifts the car and checks by hand.
- A certified rating. The bands come from machine vibration guidance (ISO 10816-1) and are a rough guide for a car. Treat every reading as a good guide, not a certified measurement.
Frequently asked questions
Why does my steering wheel shake at high speed but not at low speed?
The front wheels bounce on their springs at their own natural rate. When the wheels turn at that rate, often somewhere between 50 and 70 mph, a small imbalance is amplified. Below that speed the push is too slow to build up, and above it the shake often fades again.
Why does my steering wheel shake only when I brake?
That usually points to the front brake rotors. When a rotor's thickness becomes uneven, the pads grab and release once per turn, and you feel it in the wheel and the pedal. New or resurfaced rotors fix it, and balancing won't help.
Can bad alignment make the steering wheel shake?
Rarely on its own. Poor alignment mostly makes the car pull and wears tires unevenly. That uneven wear can then cause a shake, so replace or rotate worn tires and get an alignment after steering parts are replaced.
Is it safe to drive with a shaking steering wheel?
A mild shake at one speed usually isn't an emergency, but get it checked soon, because it wears tires and steering parts faster. A shake that is sudden, violent or getting worse is not safe. Slow down, pull over when you can, and check the tires and wheel nuts.
Why can't I put the phone on the steering wheel?
Anything attached to the wheel can get in the driver's way and can be thrown hard if the airbag goes off. The dashboard near the column picks up the same shake, usually weaker than what you feel in your hands. Hold it there by hand, from the passenger seat.
Last updated .