Skrunch,
To take the slack(play) out of your steering, you loosen the 17mm nut and turn the adjusting screw OUT (counter-clock wise).All adjusting screws I have seen were Allen heads. Maybe someone has replaced the one on your car with a hex head screw. Makes no difference. Turn it out to remove the play in your steering.
Bill Lewallen Lexington,Ky. Where diesels purr and turbos whirr.