The symptoms seemed to fit with a motor needing new brushes. I read some Amazon reviews of carbon brushes and found a youtube video "How to replace the washing machine carbon brushes on a Bosch Washer" by Spares. I pulled out the washer and took the back off and determined that it wasn't the belt. The job as depicted in the video was somewhat more difficult due to some minor differences with my washer. My suggestions are to pry the motor out with a screwdriver, blow the dust out of the motor with canned air, and clean the commutator with a small piece of 3m pad. My wife was able to get the new brushes reinstalled which was a test of patience! The terminal block on the motor proved nearly impossible to install blind. In the end, it worked and returned the washer to service and saving a service call and a new motor or a new washer.