While not exactly the issue the OP has the cure I employed might help to strengthen the doors...
First my smaller closet door came apart in my hand one day when I opened it. After 8 years of bouncing down the road the framing split/separated. About 6 months later the larger closet door did the same thing. Both times I used this trick to strengthen them.
First I bought "L" shaped braces at the local hardware store and screwed them, overlapped, into the the two pieces at the top and bottom of each door. I used Gorilla Glue drizzled into the cracks and secured them with several clamps. The next day I sliced/scraped the excess glue off and they are both stronger than they were originally built. More than a year later both work fine and show no signs of another failure.
Straight bracing might work for the OP if he could clamp the separating sections together and then screw the braces in place to lock them in position. Good luck.
:C