In short
A dryer that has started making a noise is usually carrying something it should not, or running on a worn roller. The ranking here begins with machine not level, or feet not all carrying weight. The empty-drum test separates those two cases in two minutes.
What you observe
- A rhythmic thump that keeps time with the drum — Something in the drum, or a flat spot on a roller.
- A squeal that rises with the drum speed — A belt or an idler pulley under load.
- A scraping or rubbing sound — The drum is touching something it should not — usually a worn glide.
- NEAR MISS — the noise only happens when the door is closed — Door catch or hinge, which is a nuisance rather than a fault.
Causes, most likely first on a Smad dryer
- Machine not level, or feet not all carrying weight — A dryer that rocks knocks on every drum revolution and walks slowly across the floor. Ranked first on a Smad dryer: it turns an ordinary vibration into a knock, and it costs nothing but a spanner to correct.
- Coins, buttons or a zip pull loose in the drum — Small hard objects tumble with the load and thump on every revolution.
- Duct or cabinet panel resonating — A flexible duct touching the wall, or a loose rear panel, buzzes in time with the motor.
- Drum support roller worn or flat — The drum rides on rollers, and a worn or flat one thumps once per revolution for months before it fails.
Check in this order, and why
- Push the top corners and see whether the machine rocks — Any rock means a foot is not carrying weight.
- Empty the drum completely and run it for a few seconds — Check inside the lint trap housing with a torch as well.
- Press on the cabinet panels and the duct while the machine runs — Check the duct is not crushed against the wall.
What an owner can safely check
- Level the dryer on its feet until it does not rock, with all four carrying weight — Do it in its final position: a machine levelled and then pushed back usually needs it again.
Tools: spirit level, adjustable spannerAbout 20 min
- Empty the drum, check the lint trap housing with a torch, and run the machine empty for a few seconds — A noise that disappears on an empty drum came out with the washing. Check pockets before loading.
Tools: torchAbout 15 min
- STOP HERE if the next step needs a panel off, a meter on live terminals, or the gas train — That is where the owner checks end; gas and high-current work are never owner work.
Before you open anything
Safety
Isolate the dryer at the breaker before a panel comes off and let any capacitor bleed down. Treat lint as fuel: the filter every load, the duct on a schedule, and never run the machine with the duct disconnected. On a gas dryer, a smell of gas means do not switch anything on or off, leave the building and call the gas utility or 911 from outside — never search for the leak yourself.
When to call a technician
Owner work is emptying the drum, levelling the machine and easing the duct clear. Rollers, belts, idlers, glides and seals are behind panels and are a technician's job. If your unit is an absorption model running on gas, the gas side is not owner work: a licensed gas technician handles the burner, the flue and any smell of gas.
Nearest pages of this class
What this page does not cover
This is the generalised Smad dryer page. A family- or model-specific page, where one exists, is linked above and is the more precise answer for your unit. Left out on purpose: part numbers, connector colours, the order panels come off in, and every torque figure — a generalised page cannot be right about any of them.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
