Remove the tiny screw on the bottom of the little black plastic piece
on the outside of the door, piece should pop off after that, be gentle
with it as it has clips holding it in.  Then there are two bolts that
you can try to tighten, didn't make any difference with mine, tried
various things, even putting some emery cloth in the moving mechanism
for friction.  Ended up adjusting them where I wanted them then
drilling a hole and putting a screw through the bracket into the arm