I've had one of these awaiting a service ever since I bought it 2nd hand. Finally got round to it yesterday. After servicing, without the body on, it ran like a sewing machine. Put the body on and it sounded like a bag of graunching nuts. Concluded the body was acting as an echo chamber so stuck blu tack into the voids (obvously the body, not the chassis!). It was ok for about minute, then the graunching started again. Fiddled with it again, but still graunching, yet no noise without body. The body is clipped on ' no securing screws. Any suggestions?