Research indicated it was probably a roller. Disassembled and inspected each roller. One of them didn't spin freely. Replaced the roller and the noise is gone. Most of the work required a screwdriver. Socket set (maybe could've used a wrench) was for the roller. Also used channel locks to loosen the water hose. Most of the time spent was due to my ignorance of the dryer disassembly/reassembly. If I had to do it again it would probably take ~60 minutes.