My house has 4 sets of folding doors that hang from a top rail. Some of them are drooping a bit where they meet when closed. I looked at the roller-pin at the top corners to see how they were built and they appear to be spring-loaded plunger that goes into a cylinder on one end and has a plastic wheel/roller on the other to fit into the track.

The cylinders appear to be just banged into the door tops and do not have threads to adjust the door height.

I held a straight-edge against the track and determined the track is NOT sagging in the middle.

Does replacement hardware exist that would raise the handle sides of the doors so they don't scrape on the floor or carpets?

 

Do your doors have a pivot on the floor at the bottom of the side jamb? If they do, the top pivot at the jamb has an adjustment screw on the inside which can be loosened to allow the top pivot to be moved slightly toward the jamb to raise the edge where the doors meet.

 

You may need to remove the door to see the screw that you need to loosen to make the adjustment. There is often adjustments that can be made at the bottom. This is where they usually get knocked out of adjustment. Just lift the door and set the pin back down either to the left or right depending on how it needs adjusting.

 

And, finally, if your hardware is damaged and needs replacement, there are inexpensive hardware kits available at your local hardware/big box stores..

 

Got it! Many thanks to you and the other gentleman. I am now a folding door expert! Found the adjustments and was able to realign 3 sets perfectly! The War Dept. even gave me a medal and I don't have to sleep on the couch tonight!!!