Dryer repair kits include support wheels, an idler pulley, a drive belt and instructions. Kits vary according to the age, model and size of the dryer. Unbranded dryer repair kits that fit several models are available at outfits such as Home Depot.
All these items are used to change the dryer drum belt, which causes the drum to squeak when worn. If the belt breaks, the drum does not move at all. These repairs require the removal of the dryer drum, so the machine needs unplugged from the power source.
The support wheels, sometimes called rollers, are installed below the drum. Though it is typical for one wheel to show more wear than another, they both need changed at the same time. They are held on with a nut or a clip. Each one needs a drop of oil after replacement.
The idler pulley puts the tension on the belt, and is usually near the top of the drum. It is spring loaded, which holds the belt in place. When replacing a worn belt, the old belt is cut before the drum is removed. The new belt is fitted into the belt groove and the drum replaced. The idle pulley, which may also be replaced if worn, is reattached.