HOH=
Halo of Heat, Maytag's description of a dryer design introduced about 1957 where the electric heating element was positioned in front of the drum in a circle. Air was drawn over the heating element, thru the drum and then exhausted from the center of the rear of the drum. With the heating element in front and the blower mounted at the center rear of the drum, it made for a shallow drum, much smaller than their previous check rated dryer. In the original Highlanders, the drum was not porcelain, but zinc-coated steel. An aunt of mine had to have her 1957 dryer drum "recoated" in the 70s but with what, where or how, I do not know. Maytag kept this ancient engineering with all of the heavy steel construction way past other dryers in their refusal to update a design as if their machines were memorials to someone.
Rinso, if your dryers had sat for any length of time and the belts had developed flat spots, you would have heard thumping when it was in operation. My 1967 GE does not thump and it has the belt around the porcelain drum.