Dryer Drum Not Spinning But Motor Runs — What to Check

Quick Answer

If your dryer's motor runs (you can hear it humming) but the drum does not turn, the drive belt has broken. The drive belt is a thin, flat rubber belt that wraps around the drum and loops through a motor pulley and an idler pulley. When it snaps, the motor spins freely but has no connection to the drum. Less commonly, the idler pulley has seized or the drum roller bearings have failed, preventing the drum from turning even though the belt is intact. A belt replacement is a $5-15 part and takes about 30-45 minutes.

How the Drum Turns

The mechanics of a clothes dryer are straightforward. A small electric motor spins at high speed. A long, thin belt wraps around the entire circumference of the drum (the big cylinder that holds your clothes), then loops down around a small motor pulley and an idler pulley that maintains belt tension. When the motor spins, the belt turns the drum. It is the same principle as a bicycle chain connecting pedals to the rear wheel.

The belt is the weakest link in this system by design. It is a wear item that is meant to be replaced, similar to how brake pads are designed to wear out before the rotor does. After years of use, the belt stretches, cracks, and eventually snaps. When it breaks, the motor has nothing to drive, so it just hums or runs freely while the drum sits still.

Confirming the Belt Is Broken

Before you buy a new belt, take 30 seconds to confirm.

Open the dryer door and try to spin the drum by hand. On a dryer with a functioning belt, the drum will feel heavy and resistant because the belt connects it to the motor and idler pulley. If the belt is broken, the drum will spin freely with almost no resistance -- it will feel loose and light, and you will probably be able to spin it with one finger.

That is your confirmation. If the drum spins freely, the belt is broken.

If the drum does not spin freely by hand -- if it feels stuck, grinds, or only rotates partway -- the belt may be intact but the drum rollers or glide bearings have failed, physically preventing the drum from turning. This requires a different repair (see below).

Replacing the Belt

This is one of the most common and most accessible DIY appliance repairs. You need a new belt (look up your dryer's model number to get the exact replacement), a screwdriver or nut driver, and about 30-45 minutes.

When It Is Not the Belt

Seized idler pulley. The idler pulley is a small wheel on a spring-loaded arm that keeps tension on the belt. If the idler pulley's bearing seizes, it stops rotating and the belt slides over it rather than driving the drum. You will often hear a loud squealing or burning rubber smell before the belt eventually snaps from the friction. Replace the idler pulley at the same time as the belt -- they cost five to eight dollars and are right there when you have the dryer open.

Failed drum rollers. The drum sits on two to four small rubber rollers that let it turn freely. If these rollers wear flat, develop flat spots, or seize on their axles, the drum cannot turn even with a good belt. The motor may trip its overload protector and shut off, or the belt may slip and squeal. Replacing drum rollers is slightly more involved than a belt but is still a manageable DIY job. Replace all rollers at the same time -- if one has worn out, the others are close behind.

Motor failure. If the motor does not hum at all when you start the dryer, the motor itself may have failed. But the question in this article specifies that the motor runs, so if you can hear it humming, the motor is working -- it just is not connected to the drum because the belt is broken.

Preventing Belt Failure

Dryer belts last 5-15 years depending on usage, load sizes, and heat settings. You cannot really prevent a belt from eventually wearing out, but you can avoid premature failure.

Do not overload the dryer. Heavy loads put more stress on the belt. A drum packed so full that clothes cannot tumble freely forces the motor to work harder and stretches the belt faster.

Clean the lint trap before every load. A clogged lint trap makes the dryer run longer cycles, which means more belt wear per load of laundry. It also increases the risk of dryer fires, which is a significantly more serious concern than belt wear.

Listen for warning signs. A belt that is about to fail often produces a thumping or squealing noise for days or weeks before it snaps. If your dryer suddenly starts making rhythmic thumping sounds, that is often a fraying belt slapping as it goes around. A squeal on startup that fades is often a belt that is losing grip. Replacing it proactively is easier than dealing with a broken belt and a full load of wet clothes, much like how addressing a faucet drip early prevents bigger plumbing issues.