Funny you should post this. Mine started to make noise by the motor unit this past week. I grabbed the manual thinking there might be a lube spot. It looked like the motor/ drive was an assembly. The troubleshooting section didn't seem to address this directly, but did mention something like motor hums briefly? which referenced the trolley adjustment. What I found was the trolley adjustment had loosened. (the spec is 1 1/4" from the base of the nut to bracket on mine) Hopefully, you still have your manual for the procedure. Once I re-tensioned the trolley nut the noise had gone away. Hopefully it stays away. Maybe this will help.