Ya know what, maybe someone has had that apart before Old31. Only the nut and the washer are on the outside of the door. If that stud gets installed after the assembly gets dropped down into the door (from the outside) there will never be anything to tighten up to, and all it will do is pull the bottom inward. Thus it will pitch the assembly out at the top.
1 drop assembly into the door
2 start some fasteners and leave them loose. this hold the unit in place for you
3 take that stud in-hand, and put your arm in the door. Thread the stud in the bottom of the assembly
4 start your nut and washer on the outside of the door
5 align everything and begin snugging down slightly
6 adjust your pitch of the assembly by turning the stud with a screwdriver.
7 snug down your lower nut
8 close the door for the final alignment check
9 if good, tighten things down, and put the door panel back on.