Al V's picture really helps show the problem and can help people describe what to can be done. As you can see in the picture, the door is moving in 2 directions. The top hinge is moving to the left and allowing the door to drop and sag. The bottom hinge is moving to the right and allowing the door to do the same. Also to note, the hinge is also wearing and allowing the door to go straight down, if you look at the hinge you will see where all the weight
is and it wears there. Al's picture does not show it but I have a huge gap at the top of the door and very tight at the bottom.
I did a little repair on my hinges with JB Quik (epoxy). It was the day before we were to go camping and I realized the door wouldnt even stay closed on the catch at times and I really studies it for a while looking for a good fix. Seeing no good fix, I took the pins out of the door and held it up to the trailer to see what I could do. The top hinge needed to go up 3/8 of an inch and the bottom one needed 1/4 inch. That was way more than I could shim and I could have redrilled but didnt bother due to the fact that I definatly need new hinges. I figured just tightning up the sloppy holes and building up the wear surface would have to do.
Doing the holes was pretty easy. I mixed up a little epoxy and slathered it in the hole, dont wory about it being pretty. JB Quik is claimed to be a 5 minute mix but I found 9 to be the last workable minute for it. Right at 9 going into 10, I used a drill bit to gently take out the excess epoxy, remember, top hinge keep the bit to the right and vice versa on the bottom so it will help raise the door. After that I put a gob on the bottom of both hinges where the door part of the hinge rides and it wears, again dont worry about being pretty. After it was totaly dry I used a file to smooth it and remove some materal as it was so high now it wouldnt allow the hinge to be put back together.
All total it took about a hour to fix due to the speed setting of the JB Quik (I usually recommend JB Weld but I was pushed for time). It is not a great way to fix the problem but works.
Maggie, your door will continue to sag more and more untill it hits the camper when closing or failes to latch (mine hit at the bottom on the inside and cracked a chip out). Adding a good grease will help slow it though. Open your door about 2 inches, grab the edge and lift, you will see the slop in the hinges. If there no slop (there will be) it could have been mounted that way from the factory (unlikely due to the molding not lining up and that would stick out like a sore thumb) or the rest of the trailer is saging some causing the door to not fit perfectaly. If you truly have no slop, Nancy is right you can remount the hinge but I disagree with her in the holes causing problems. It is common practicse to add a hardwood dowel and epoxy to take up the space that the previous holes made and to put in a pilot hole for the new screw.
Rich - Trillium with the saggiest hinges on the planet