When the GMC door has a gap at the top and at the bottom but the  latch area makes contact it is easy to assume that the door has been  bent.  There is a section in the GMC Maintenance Manual giving  details on how to recurve a door.    Many GMCers have posted  information that a door gets bent when it swings open hard against  the side of the GMC outer wall by the hinges of the door.  Apparently  it can bend there when the rub strip on the door and on the sidewall  hit;  however, this does not explain why the latch side of the door  often appears to be bent more than the hinge side.  If the rub rail  was doing the bending it wouldn't bend more at the latch side.

A few years after buying my GMC, I started to have problems with my  door not sealing at the top and bottom and upon examining it I found  that the wall by the latch side seemed to be pulling away from the  cabinet wall by the side of the refrigerator.  In fact, I had a 1/2"
gap between the outer curve of the cabinet wall and the inside of the  GMC wall  (Picture 1);  and yet, the cabinet wall touched the GMC  wall at the top and bottom which indicated to me that the cabinet was  not pulling away from the wall.

It is my belief that the wall of the motorhome has begun to bulge  outward.  I have termed this "Middle Age Spread".  The constant  jouncing of the GMC aluminum body up and down with the weight of the  air conditioner on the roof has probably caused this bulging over  time.    My fix for this is to pull the outer wall back toward the  inside of the GMC and to bolt it to the cabinet wall to keep it in  place.

To get the wall back into place it is necessary to either pull it  back or push it back.  If you have a kitchen window on the opposite  side that opens you can cut two pieces of 2x4 lumber to fit across  the openings.  Make one long enough to fit across the door frame and  the other long enough to fit across the window.  Let them extend a  few inches past the openings.  I used a "come-a-long" winch to fasten  to the 2x4's and pulled in the wall by the door until the
refrigerator cabinet wall nested back into the area adjacent to the  door latch and the gap appeared to be tightly closed.  Position the  2x4 near the center of the door frame by the latch and the kitchen  window one just over the countertop.  Fasten the cable of the winch  to the 2x4 adjacent to the rear of the door opening next to the  latch.  Be sure to pad the outer wall of the GMC between the wall and  the ends of the 2x4.  I used some cloth and then a  piece of 1/4"
plywood to spread the force.

If you don't have an opening window on the opposite side from the  door you could park the GMC next to a concrete wall, a strong tree or  a telephone pole and use a jack between the wall, tree or pole and  the side of the GMC by the door latch.  Again, be sure to use some  padding to protect the wall and some plywood to spread the force and  to keep from pressing a dent into a small part of the outer wall.

Once you have the wall pulled back against the curved side of the  cabinet (Picture 2) you have to fasten the outer wall to keep it in  place.  Do not release the tension on the winch or jack until you  have bolted the wall into place.

Since the cabinet wall is pressed wood it is not very strong in  tensile strength and in order to bolt to it and have it hold, I made  up a 2" x 8" piece of steel about 1/16" or more in thickness.  I
drilled 1/8" screw holes around the two short sides and one long side  about 1" apart  (Picture 3).   To gain access to the inside of the  cabinet wall you can  reach through the outside  refrigerator vent opening and remove some insulation on the right side toward the door.
I centered the metal plate vertically on the center of the latch.  It  was positioned flat against the inside of the cabinet wall with the  two outer corners of the plate just touching the outer curve of the  wall.  I screwed the plate to the inside of the cabinet wall using  coarse thread screws (often called "deck screws" or "wood bullets").  These will hold well in pressed wood without  removing too much wood as they are screwed in.  After the plate is in place I drilled two
holes through the door latch, the cabinet wall and the inner steel  plate  (Picture 4).   The holes are 7" apart, centered on the door  latch stud.  The holes are place as close to the inner lip of the
latch plate as possible but leave enough space to clear the screw  heads.  I used a small head screw in order to get them as far back as  possible.  The two screws are 1/4" diameter.  They are fastened with  a washer, lock washer and a 1/4" nut on the inside.  After you have  the two bolts tightened you can release the winch or jack pressure.

My GMC has had this fix in place for about 8 years now and it is  still holding well and no longer has a gap at the top and bottom..  I  have not had to bend the door and the door has never needed another  adjustment since doing this

Emery