Upon removal and dismantling the distribution blower after experiencing no flow and squealing, i discovered that the shaft to which the blower wheels is attached is not secured to the rotor. Further, there is evidence of high temperature coloration on the shaft. The motor runs, but fans are still. How is the shaft supposed to be connected to thevcd rotor? Motor appears competent. By the way, I have replacement on the way but am curious as to how common this is.