Frigidaire Dryer, FER341AC0, 02/04, has become VERY loud in the past week. So loud that it is hard to talk over it. To resolve the problem thus far I have: taken the dryer apart, vacuumed out all the lint, check all the screws, cleaned the exhaust all the way out of the house, bought a maintenance kit and replace the belt, replaced all the felt, replaced the ball thing that holds the drum and replaced the holder it goes in, greased it, checked the operation of the drum to make sure it wasn’t touching anything, replaced tightener pulley and everything else a dryer layman could think of to do. Put it all back together and run it with no heat and it seems to work fine. Once I turn it on heat the noise level grows as soon as the heat increases. The element and thermostat/thermistor seem to work fine. I did notice that the element seemed a little clinky and that a few of the little white things that hold the element off the metal were loose, but not really in disrepair. I can’t find anywhere where metal might be vibrating or rubbing against something else. If you turn the motor, the fan, or the drum by themselves they are quiet as a mosue. Airflow is clear and the dryer works fine…except for that it is extremely, annoyingly loud. I would replace the element, but the maintenance kit was a waste of $45 and am afraid to drop $70 on an element and then end up still having to buy a new dryer.
You seem to have done every thing so I am just taking long shots.
I do not think it is the element, something is expanding due to the heat and causing the noise.
Let it get hot and then try rotating the drum perhaps that will allow you to narrow down where the racket is coming from.
Clean/check the blower wheel.