The short answer
Dryer noise is unusually diagnostic: the character of the sound names the part more reliably than any test does. A squeal is a bearing, a thump is support, and a rattle or scrape is usually something loose that does not belong there. Turn the drum by hand with the power off. A noise you can reproduce by hand is mechanical and in the drivetrain; a noise only present under power is the blower or the motor. On a Smeg dryer the cause that ranks first is drum support rollers or front glides worn.
What you observe
- A rhythmic thump, once per drum revolution — Support wear — rollers at the back or glides at the front.
- A squeal that is worst on start-up and eases as the machine warms — A dry bearing, almost always the idler pulley.
- NEAR MISS — a grinding that rises and falls with the motor, not the drum — That is the motor end of the machine and it is not an owner repair.
Causes, most likely first on a Smeg dryer
- Drum support rollers or front glides worn — The drum rides on rollers at the back and slides on felt or plastic glides at the front, and both wear flat, giving a rhythmic thump once per revolution. It ranks first on a Smeg dryer because it is the commonest cause on this platform.
- Idler pulley bearing dry — The tensioner that keeps the belt tight spins on a small bearing, and when it dries out it squeals — loudest on start-up and when the drum is loaded. Second on this platform: it is a small, unlubricated bearing doing continuous work, so it is the part that squeals first.
- Something loose inside the blower wheel — Coins, buttons and pen caps find their way past the lint filter into the blower housing and rattle furiously against the wheel. Ranked here because it is the one cause that starts suddenly rather than gradually, and it is often free to fix.
- Machine not level, or standing on a flexible floor — An unlevel machine drums against the floor and walks, and the sound is the floor as much as the appliance. Last, and the reason to work down the list rather than guess: the stance changes whenever the machine is moved, and it is the cheapest of all the causes to correct.
Check in this order, and why
- Turn the drum slowly by hand and listen for a once-per-turn thump — A noise that repeats with drum position is support wear, not the blower.
- Start the machine empty and listen for a squeal that fades as it warms — A squeal that eases after a few minutes is a dry bearing, not a belt.
- Listen for whether the noise stops the moment the drum stops turning — A rattle that dies instantly with the airflow is in the blower.
What an owner can safely check
- Spin the empty drum by hand and note whether the thump repeats at the same point — A flat spot you can feel through the drum is the answer.
About 10 min
- Check the lint filter housing and the pockets of the last load for what is missing — Anything small and hard that went in with the wash is a candidate.
Tools: torchAbout 10 min
- Level the machine on its feet until no corner rocks under hand pressure — On a suspended floor, a sheet of ply under both feet helps more than the feet do.
Tools: spirit level, spannerAbout 20 min
- STOP HERE — the next check means a meter, a panel, or both — The ranking above tells you what to ask for; it does not make the remaining tests owner work.
Before you open anything
Safety
Unplug the dryer or switch off its breaker before removing any panel, and if it is a gas machine, shut the gas valve at the appliance before moving it.
When to call a technician
Call when the noise is a metallic scrape or a grind that follows the motor rather than the drum, or when the drum will not turn freely by hand with the power off. On a European-controlled machine, ask what the control was reporting when it stopped — it usually records why it aborted, and that shortens the visit.
Nearest pages of this class
What this page does not cover
This is the generalized page for a Smeg dryer. It does not carry anything model-specific: no part numbers, no wiring colours, no panel sequence and no torque figures, because those differ between families sold under the same badge. Where a family- or model-level page exists it is linked above, and it is the more specific answer of the two.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
