After first checking for obstructions, and screws that may have worked themselves out and become obstacles. I continued looking and discovered that the aluminum piano hinge now has a lot of slop in it such that I can lift the trailer door up about an eighth of an inch or so because the hinges have worn, sort of like the way that a chain wears. So there are gaps in between each segment of piano hinge now.
I came up with an interesting fix, very very simple but it's working. What I did is insert a piece of wire through the hinge and bring it back so that it is a spacer and will not allow the door to drop down anymore. The wire I used was some kind of loop hook, I don't know what it was for maybe a very small curtain or something.
Anyway you can see in the picture what I'm talking about; that wire sticking out used to be a loop hook and now it is a hinge shim. I just bent it down and left it long in case I need to modify it in the very near future.
I'm quite pleased that the door closes easily now. :-)
