Replaced both drum support rollers and the belt tension pulley assembly.
Most difficult part was removing the retaining clips on the drum support roller shaft. The clip removal tool I had was too large to fit into the holes in the clips. I had to pry the clips out with a screwdriver and pliers.
The second most difficult part was re-attaching the pulley assembly bolt and nut.
After replacing the parts, the noise was gone. The belt tension pulley seemed to be the failing part. It was not spinning freely. The support rollers did not bind when spun.