Brenda and Alex.
Both your Kenwoods have the same fault. The shaft, on which the control knob rotates, has gradually been pulled from the motor casting by the action of the spring fitted behind the knob and cam assembly. The shaft has knurling on it and is pressed into the aluminium motor housing.
Sooner or later, the shaft may come completely out as the one on my A901 did. I fixed mine back in with "Epoxy resin adhesive" after removing motor from machine.
Andy
February 2006