The short answer
On a full-size dryer the noise names the part: a rumble is the drum rollers, a squeal is the idler, a rhythmic thump is the belt, and a rattle is something in the blower. Turn the drum by hand with the power off and most of this becomes obvious.
What you actually see and hear
- A low rumble that rises with drum speed — Drum rollers or their shafts, worn.
- A squeal, especially when cold and fading as it warms — The idler pulley.
- A rhythmic thump once per drum revolution — The belt, or something stuck to the drum.
- A rattle or clatter that comes and goes — A coin or a button in the blower wheel.
- NEAR MISS - a loud drone with poor drying — That is airflow rather than mechanics, and it belongs on the heating page.
Causes, most likely first on this machine
- Drum support rollers — First on a full-size machine. They carry the whole weight of a loaded drum and they wear predictably with use, producing the classic rumble.
- Idler pulley — Second. Its bearing is small and hard-worked, and it squeals before it fails - often loudest on a cold start.
- Foreign object in the blower wheel — Third. Coins and buttons pass the lint filter and end up here, and the rattle is startling out of proportion to the cause.
- Belt — Fourth. A worn belt thumps once per revolution and eventually breaks, at which point the drum stops turning altogether.
- Something stuck to the drum or trapped at the front seal — Fifth, and free to fix once found.
- Motor bearing — Last. It is genuine but least common, and by then the other four have usually been ruled out.
Check in this order, and why
- Empty the drum and run it briefly — Separates the load from the machine immediately.
- Note whether the noise changes with drum speed or with temperature — Speed points at rollers; cold-start squeal points at the idler.
- Turn the drum by hand with the power off — Roughness and rumble come through the rim.
- Check the lint filter housing for coins — The route by which things reach the blower.
What an owner can safely check
- Run the dryer empty for a minute and listen — Confirms whether the noise belongs to the load.
About 5 min
- Check the machine is level and not touching a wall or a washer beside it — Contact between two laundry machines is a common complaint.
Tools: spirit levelAbout 15 min
- Clean the lint filter and check the housing for coins and pins — The blower is downstream of exactly this.
Tools: torchAbout 15 min
- Turn the drum by hand and listen at the front and rear — Roughness at one point per turn narrows it further.
About 10 min
- STOP HERE before removing the front or rear panel to reach rollers, belt or blower — That is live work on a dedicated high-current circuit.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel - a capacitor can hold a charge after the power is off. A full-size dryer is on a dedicated large-appliance circuit, so switch off at the breaker rather than at any switch, and treat the terminal block as live until you have. Lint is fuel: never run the machine with the vent disconnected indoors, and never bypass a thermal cut-out to get a cycle to finish.
When to call a technician
Call once you have an empty-drum noise that tracks drum speed or squeals on a cold start - that is rollers or the idler, and both mean the cabinet coming apart. Call promptly for a rattle in the blower, because whatever is in there is also restricting airflow, and restricted airflow in a dryer is how lint fires start. A belt thump can wait for a convenient appointment, but not indefinitely: when a belt goes, the drum stops turning.
Nearest pages of this class
What this page does not cover
This page is written for the full-size vented dryer class, not for one family or model line. Where a brand- or model-specific page exists for your unit it is the more specific answer and it is linked above, so go there first if your machine is named. What is deliberately not here: drum roller, belt and idler part numbers, thermostat ratings, element specifications and vent length limits, all of which differ by family and belong on the page for that family.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
