It depends upon where the play is that allows the hour hand to swing loose.
If it is the fit between the shaft and the hour hand you might be able to very very gently crimp the ring that fits onto the shaft.
If the gears have worn get a new electric motor, these are quite cheap £3.50at Maplin see link below
http://www.maplin.co.uk/quartz-clock-movement-5034?c=froogle&u=5034&t=module
Maurice, April 2011