Section 4.8.  Council's dealings with administrative services; council's ordering of subordinates of city manager.
   Except for the purpose of investigations as provided in Section 6.8, and except in those cases where the council must, by law, deal directly with the administrative services, the council and its members shall deal with the administrative services solely through the city manager.  Neither the council nor any member thereof shall give orders to any of the subordinates of the city manager.