While on a trip a couple of weeks ago our Norcold frig door fell off when I opened it. The upper hinge had all the threads stripped. We bought a 2 inch C clamp from ACE that held it in place until we returned home. I ordered one on Ebay and got it in 3 days. It doesn't seem to be made out of steel, which explains why the steel hinge screw threads weren't damage, only the hinge.
When replacing the hinge, I noticed that the plastic bushing on the screw was tight with what I believe to be dried lubricant. This had stuck the hinge screw to the door half of the hinge allowing the screw to pivot with the door which is what wore the threads on the hinge out. The other 3 hinges were in the same condition.
I cleaned and re-assembled using white lithium. Had I done a little hinge maintenance a year or two ago I could have saved a few dollars.