, this dryer was functioning properly, but would make an awful noise during operation. The noise started just after the customer moved the unit to it's new location in the new home. Seeing as how the problem started after the move, I figured this dryer didn't take a smooth trip.
Start with the Simple Stuff
I started by lifting the top panel up to get my eyes on the drum and noticed the drive belt was about an inch to the rear from where the wear mark was located. This is a good indication that the belt has slipped off the drive pulley, but the fact the drum still turned would normally prove otherwise. But after removing the front panel and getting a look at the belt routing, the source of the noise presented itself.
Keeping the Belt Tight
The drive belts are routed around the drive motor and through an idler roller that maintains tension on the belt. Since the force needed to rotate the drum changes as clothes tumble around the drum (and become dryer) the idler helps to keep everything in check. Idlers may have rollers or glides to support the belt, and they will have some sort of spring action to provide the tension. As long as the belt is placed in the correct position on the drum, the idler will also help to keep the belt centered on the drive pulley.
On with the Repair
This machine having just been moved looks like it may have been drop tested sometime during that journey resulting in the belt jumping off the idler and getting stuck between the roller and the support arm. Since the belt had tension and was wrapped around the drive pulley, it still worked fine, except for the harmonic noise from the rubber belt rubbing on the spring steel arm. I visually inspected the belt for damage, then reinstalled it back to it's correct position. Now it sounds like a dryer again.