A high squeal from the bottom of the dryer is usually the idler pulley, a steady thump is often a flat-spotted drum roller or a worn belt, and grinding at the front points to worn drum glides or felt seal. Before taking anything apart, empty the drum, check the baffles for coins, and level the dryer.
Rule out the free fixes first
A surprising number of noisy dryers have nothing broken inside. Run the dryer empty for a minute. If the noise disappears, the load was the cause: a pair of sneakers, a zipper slapping the drum, or one heavy wet towel throwing the drum off balance.
If the noise stays with an empty drum, unplug the dryer and check three things. Reach in and shake each drum baffle (the ribs that lift the clothes). Hollow plastic baffles collect coins and screws, and a loose one clunks once per turn. Then put a level on top of the dryer and turn the feet until it sits flat side to side and front to back. Fix.com lists leveling first and iFixit says to check it before taking anything apart, since an out-of-level cabinet can rumble or squeak on its own.
- Noise gone with an empty drum: it was the load
- Click or clunk once per revolution: loose baffle or a coin inside one
- Rumble with lots of cabinet shaking: check the leveling legs
- Rattle at the back: look behind the dryer for a loose vent clamp hitting the wall
Find where the sound comes from
Location narrows it down fast. iFixit says a squeal from the top often comes from the belt, sometimes with a faint burnt-rubber smell. Noise at the upper front, around the door opening, suggests worn glides or the front felt seal. Squeaks from the back usually come from the rear rollers or the rear drum bearing, and the idler pulley sits low in the cabinet next to the motor.
With the dryer unplugged, open the door and try to move the drum by hand. iFixit links front-to-back play to worn felt seals. A drum that sags or rocks when you lift its front edge has worn supports (rollers, glides or the bearing).
High-pitched squeal: the idler pulley
The idler pulley is a small wheel on a spring-loaded arm that keeps tension on the belt. It spins very fast, and when its bearing or bushing wears, it squeals or chirps. Sears Home Services and Fix.com both name it for squeaking, and iFixit adds that a jammed pulley can give off a burning smell.
To check it, pull the plug and get access to the motor area (on most Whirlpool-built dryers that means removing the front panel; other designs open from the front or the back). Spin the pulley by hand. It should turn smoothly and quietly with no wobble. Grinding, a flat spot or a cracked wheel means replace it. The belt has to come off to swap the pulley, so on an older dryer it makes sense to fit a new belt at the same time.
Steady thumping: drum rollers or the belt
Many dryers ride on two or four rubber drum support rollers. When a roller wears or develops a flat spot, you get a rhythmic thump or rattle. Sears notes a roller can go flat on one side after a dryer sits unused for a long stretch.
With the drum out, each roller should spin freely, sit straight on its axle and still have its retaining clip. iFixit recommends replacing every roller when one is bad, since the others tend to fail one after another. Check the axle shafts for wear while you're in there.
A belt can thump too. A worn or frayed section slaps once per drum revolution, and a belt that's split along its length can tap against the drum. If the belt looks glazed, cracked or stretched, replace it with the one listed for your model number.
Grinding or scraping at the front: glides and felt seal
Some dryers support the front of the drum on plastic glides (small pads near the top of the door opening) instead of rollers. When the glides wear through, the drum rubs metal on metal against the front bulkhead and you hear grinding or scraping. Sears Home Services and iFixit both list worn glides as the classic grinding cause.
The felt seal is a strip around the drum edge that keeps air from leaking past. Once it wears or comes loose, the drum shifts and scrapes the front or rear panel. Look for shiny rub marks on the bulkhead and lint packed where the felt should be.
Replace worn glides and the felt seal together, since iFixit notes worn glides can damage the felt. The drum has to come out for this job, so do both in one teardown.
Rumble or roar: blower wheel and motor
The blower wheel pulls air through the drum and out the vent. iFixit says debris in the wheel is a frequent cause of rumbling, and a wheel that has worked loose on the motor shaft can rub its housing. A sock or wad of wet lint caught inside causes a rattle or a heavy roar.
Sears lists failing motor bearings among the causes of humming and squealing, and Fix.com says a faulty motor can hum, grind or thump. On most dryers that means a new motor. If the motor hums and won't turn the drum, see our guide on a dryer that won't start, and don't keep restarting it.
LG dryers show LE and Samsung dryers show 3C when the drum or motor isn't turning properly, and Whirlpool shows F7E1 for a drive motor system fault. A noise followed by one of those codes is a good reason to stop and inspect before the next load.
Rear squeak: drum bearing on older dryers
Some dryers carry the back of the drum on a rear bearing: a shaft on the drum that turns in a support on the rear bulkhead. As it wears, the drum gets harder to turn and squeaks or squawks, especially when the drum is loaded. iFixit says the part usually replaced is a plastic support cup.
This is the deepest of the noise repairs. The drum comes out and, on many models, the dryer has to be pulled well away from the wall so you can work at the back. On a gas dryer, read the safety note below before moving it.
When to call a professional
Bring in a technician if the noise comes with a burning smell that doesn't fade, if the drum stops turning or shows a motor code, or if the repair needs the motor replaced. Call one too for any gas dryer that has to be pulled far enough out to put tension on the gas connector.