Read the guide: Why does my washing machine shake?
How to test your dryer
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Step 1: Clean the lint screen. Take out anything that bangs, like shoes or a single wet rug.
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Step 2: Start the dryer empty on a no-heat setting, often called air fluff or air dry. This tests the dryer by itself.
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Step 3: Place your phone flat, screen up, on top of the dryer near the front. If your dryer is stacked, only reach up from a sturdy step stool.
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Step 4: Tap Start (on iPhone, tap Allow). Keep your hands off the phone and the dryer while it measures for 30 seconds.
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Step 5: Run the test again with a normal load and compare. A big jump points to the load. A high reading when empty points to the dryer.
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Step 6: Save an image of each result so you can show a repair person.
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 | Your dryer is running smoothly. Any noise you hear is probably the load tumbling, not the machine. |
| Normal | 0.71 to 1.8 mm/s 0.028 to 0.071 in/s | Normal for a dryer. Heavy or wet loads add a little shake as they tumble. |
| Rough, check it | 1.8 to 4.5 mm/s 0.071 to 0.177 in/s | More shake than it should have. Check that the dryer is level and all four feet sit firmly. If it thumps or rumbles even when empty, a worn drum roller or belt is a likely cause. |
| Too much vibration | 4.5 mm/s or more 0.177 in/s or more | Too much vibration. Stop the dryer and test it empty. If it's still this high, unplug it, check the feet and any stacking kit, and call a repair person. |
Why dryer vibration is measured by strength
A dryer vibration test works a little differently from a washer test. A washer drum spins fast, so its speed shows up clearly as a frequency. A dryer drum turns slowly, often 45 to 60 times a minute. That’s under 1 Hz, too slow for your phone to read well. So this test focuses on how strong the shake is, not how fast.
The frequency you see comes from other parts. The motor and blower fan spin much faster than the drum, often near or above the fastest your phone can measure. If the result says “The main vibration may be faster than your phone can measure,” that’s common on a dryer. It doesn’t mean the test failed. The strength reading is still useful.
Tumbling clothes also make random bumps, so the live reading moves around more than on a washer. Run the test twice and compare the two results.
Common causes and fixes
Unplug the dryer before you move it or open any panel. On a gas dryer, also turn off the gas valve behind it.
The load
A single heavy item, like a wet comforter, a rug or shoes, throws the drum off balance and bangs on every turn. Sheets can wrap around everything else and make one heavy ball. Split big items into their own load. Add a couple of towels to a small heavy load. Dry shoes on a rack or in a mesh bag.
Uneven feet or floor
Put a level on top and rock the dryer by its corners. Adjust the feet until it sits firmly on all four and is level side to side. On a stacked pair, check that the stacking kit is fitted and every screw is tight.
Worn drum rollers or glides
On many dryers, the drum rides on small rollers and plastic or felt glides. When they wear, you’ll hear thumping, rumbling or scraping, and the shake gets stronger. Rollers are a common repair and usually sold as a kit.
Worn belt or idler pulley
A belt with a flat spot thumps once per drum turn. A worn idler pulley often squeals. Both are inside the cabinet, so they’re a job for a repair person or a confident DIYer.
Something caught in the blower
Coins, buttons or a small sock can slip past the lint screen into the blower. That usually makes a loud rattle. The blower is inside the cabinet, so have it checked if the rattle doesn’t stop.
When to call a repair person
Stop using the dryer and call for help if you smell burning, the drum won’t turn, or you hear grinding. On a gas dryer, if you smell gas, don’t touch any switches. Leave the house and call your gas company from outside.
What this tool can’t measure
- Drum speed. It’s too slow to read, as explained above.
- Motor and blower speed. These often spin faster than your phone can measure.
- Noise. Squeals, scrapes and rattles are sound. A dryer can be loud with very little vibration.
- A certified result. The labels use a general machine scale (ISO 10816-1 for small machines) as a rough guide. Treat the result as a good guide, not a certified measurement.
Frequently asked questions
Why is my dryer shaking so much?
The most common causes are a dryer that isn't level, a loose foot, or a heavy load like a wet comforter bunched on one side. Worn drum rollers and a worn belt also cause thumping and shaking. Test it empty first to tell the load apart from the machine.
Why is my dryer so loud?
Squealing often comes from a worn idler pulley or drum glides. Thumping or rumbling usually means worn drum rollers or a belt with a flat spot. Rattling can be coins, buttons or a sock caught in the blower. A dryer can be loud with very little vibration, so listen as well as measure.
Is it normal for a dryer to vibrate?
A little, yes. The load tumbles and the motor and fan spin, so you'll always feel a light hum on top. A reading of Smooth or Normal when empty is what you want.
Why doesn't the test show my dryer's drum speed?
A dryer drum turns slowly, often 45 to 60 times a minute. That's under 1 Hz, too slow for your phone to measure well. The frequency you see comes from something else, so go by the strength label instead.
Can a shaking washer make my stacked dryer shake?
Yes. A stacked dryer sits right on top of the washer, so an unbalanced spin shakes both. Test the dryer while the washer is off. Stacked units should always use the stacking kit your dryer's maker lists for that washer.
Last updated .