Clasps

• Review the operating instructions that came with your Bosch front-loading dryer. In general, the manufacturer recommends that you fasten snaps, close zippers and remove belts prior to loading the dryer with laundry; otherwise, open clasps can hit the sides of the drum as the laundry tumbles and create excessive noise. Belt buckles are notorious for making scraping sounds as they rotate inside the drum.
  
  

Metal Objects

• Metal objects inside your Bosch front-loading dryer can produce scraping sounds as they roll around at the bottom of the dryer and drop from the baffle dividers onto the drum floor. Stop the dryer mid-cycle and feel inside the drum for any keys, pens or screws. Eliminate any loose object that you find to quiet the dryer.
  
  

Power Source

• If you own a gas front-loading dryer, ensure that the gas line isn’t banging against the dryer, when it’s on, as this can produce a vibration noise that may sound like something is scraping the side of the dryer. The same noise can be caused by a power cord that’s too close to the back of an electric dryer as well. Reposition the gas line or power cord so it’s not touching the dryer.
  
  

Thermostat

• Inside your Bosch front-loading dryer are a number of thermostats that monitor the air temperature of the drum during a routine drying cycle. Each thermostat is mounted to the interior of the drum by two or more screws, depending on the model. If one of the screws comes loose, the thermostat might sway back and forth as the drum turns. Stop the dryer and inspect each thermostat to confirm that it’s securely attached. If you discover that a thermostat is loose or dangling, tighten or replace its lost screws.
  
  

Gliders

• Gliders are the plastic coverings that fit over the edge of the drum’s rim. They protect the drum’s edges from scraping against the cabinet as the front-loading dryer tumbles. Over time, the gliders can split and wear away. When this happens, you might hear a scraping sound inside the dryer when it runs. Contact an authorized Bosch repair technician to evaluate the condition of the gliders on your dryer. If the technician determines that the gliders are worn, they will need to be replaced. It’s a good idea to replace all of the dryer’s gliders at one time since, when one goes bad, the others are likely wearing as well.