I have a Kato C44-9W and a Kato SD40-2 that both have a buzz when they are in reverse. Any ideas on how to quiet them? Jerry
Welcome to Trainboad Jerry. I don't have the locos you mention but my KatoGP38-2 has a metal shield that comes down from the top and covers the armature. The way the motor is held in place allows some movement. When running forward, the torque keeps the motor in place. In reverse, the torque causes the motor to angle slightly to one side allowing the armature to brush the metal shield causing the buzz. That's my experience and don't know if your locos are constructed the same way. I have tried to fix mine by firming up the motor mount so torque won't angle it. I am also trying to run the loco without the shield but a new current path has to be devised. Hope this helps.
