Dryer drum roller assembly. Includes the roller shaft and mounting clips. As the bearing in the roller wears, it self-lubricates so no grease is needed. If the dryer is noisy then one or more of the rollers may be worn. The rollers should be replaced in sets either both front or both rear.
Dryer drum drive belt. 1/4 inch wide with 4 ribs and 3 grooves. The drive belt is a very long, slender belt that wraps all the way around the dryer drum, around a tension pulley, and then around the drive motor pulley. If the drum will not turn when the dryer is turned on the belt is likely broken.
Idler pulley wheel with bearing
Dryer drum drive motor with pulley. If the dryer does not start the motor could be bad. Before replacing the motor the door switch and thermal fuse should be tested to determine if they are defective.