The problem with your hinges seems to be a problem with all AMC cars of the era. I have a Javelin and a AMX and both cars had the same problem with the hinges (both times it was on the drivers side). What wears out is the bushings that are on the hinges. These bushings (from AMC) are made of some kind of plastic and after a few years they become brittle and will literally fall off the hinge itself. The solution that I did was I went to the auto parts store and bought brass ones that fitted a Pinto or Chevette (I think). I do not remember for sure which car I ended up buying, but I am sure that they were made of brass and fit perfectly. Another source for these bushings is American Performance base out of Coca Beach, Florida. They can be found on the Internet and I beleive that their website is Americanperformance.com I did this to my cars 10 years ago and I have not seen any sign that the bushings that I installed have any hint of failure.