"Edwin Pawlowski

Most disposals have a couple of metal parts that help with the
grinding.
Starting empty they may slam outward from centrifugal force. Try
putting
some garbage in and see if that stops the bang. Never had a GE so I
don't
know if it is normal. "


I agree. I've seen various makes of disposals do this too. But it's
usually only occasionally on start up, not all the time. Probably
depending on how some food left the grinding widgets when it shut off.
It seems to happen also if some small object, like a small pit has been
bouncing around inside.