The car is a 1970 Dart. Working on replacing the turn signal switch. The arm (what sticks out of the column) is held on the switch with a long finely threaded screw which goes through a metal bushing in the switch and threads into the end of the arm. On the end of the arm is a cast rib that should keep the arm in position on the switch. That rib is wider than the V shaped notch in the face of the bushing. That seems to be why the arm loosens up over time until it doesn't function. Has anyone else run into this? I suppose I could file out the V until the rib fits nicely in it. Just wondering if anybody ran into this before?