Is your dryer loud? Does it sound like you are drying a pair of sneakers or shoes in your dryer? The rumbling or thumping sound could be caused by worn drum support rollers.
The drum rollers support the dryer drum on some models and makes of dryers (like those made by Kenmore or Whirlpool.) Drum rollers can either be on the front of the dryer drum, such as on a cabinet door, or on the back of a dryer, or both, dependent on your dryer’s model.
Over time, the rollers (see below) wear down and the shape of the rollers change and become elongated, forcing the drum to spin up and down on the non-round wheel surfaces. Even if the rollers look perfectly round to your eye, they might be worn out enough to need replacement.
To access the front dryer drum support rollers (as seen on this video) you will need to remove the dryer’s door. To access the two back dryer drum support rollers, you will need to remove the dryer drum from the cabinet.
When replacing the drum rollers it is a good idea to also change the front drum glides, drum belt, idler pulley and clips. All of these items are economical and easily changeable when replacing the glides. Whirlpool Kenmore models have a dryer maintenance kit that contains all of these items in a single kit.