I'm stumped. I've been working on kenmore washers and dryers for 40years. I'm an auto mechanic. My dryer started making noise so I took it apart and inspected it and replaced the rear main bearing with a new one while I had it apart. The front drum guide was replaced not long ago and still looks in perfect condition.The dryer makes noise when I have the heat on but if I run it without heat it sounds alright. If i have heat on it starts making loud noise within 5 minutes. The noise it makes sounds like a vibrating plate as if the plate around the heating coil is vibrating. I've replaced the motor in this machine about a year and a half ago or two years ago. I haven't looked at the electrical schematics yet to see if the heater feed runs though the motor switch or not. Im thinking it could be the motor but at the same time it runs with minimal noise when it's on air dry. Im looking forward to anyone one that has mechanical knowledge. Thank in advance:)

Ya the model number sticker wore off so I wrote it down and must have wrote it down incorrectly. I'll take a picture of it when I get a chance and record the sound coming from it as well. It's just a basic dryer with no bells and whistles.