Finished cleaning today. First time since mid-October Ash pan about 2/3 full; cleaned combustion fan blades; temp probe; exhaust pipe; burn pot; area under igniter; cleaned circulation fan blades and fines box. The squeal that we had came from the bronze bushings under the fines box cover. They are part of the slide assembly. So I did spray them with a silicon lubricant as it happened again about 2 weeks ago. Earlier I had stated that these were bushings for the auger.