My father's been complaining that the passenger side split doors have been getting harder to open and close. In particular is the left one. The right one feels like the others. The left, one feel like extra effort is needed to open and close it. He had sprayed the hinges and metal stop strap many times with all sorts of lubricant. Water displaced #40 seems to work the best. I am curious if this is a common problem or not. The back split doors don't seem to have this problem.