If you notice your dryer making many different noises while it operates, your drum might be hitting its casing, which eventually damages other components in the dryer, if not the drum directly. This happens often because you did not level the dryer or recently moved it and forgot to level it. Sometimes it gets out of a level position on its own. You must adjust the feet under it to fix the issue.
Place a construction level on top of your dryer to verify the level. You should have a bubble off-center.
Get under the dryer and check the legs. Unscrew the top locking nut with either a 3/8-inch wrench or an adjustable spanner. This frees the leg for adjustment.
Raise the leg opposite the direction of the bubble or lower a leg that sits in the direction the bubble points -- either way works fine. Continue checking the bubble every few turns of your wrench to see if it sits in the center. Once you notice the bubble has centered, screw in the locking nuts you unscrewed and test your dryer.