How to repair a bi-fold metal door it keeps coming off track?
improperly installed or adjusted! Possibly the wheels that ride on the track are worn out and can be replaced at your local home center in most instances.
I seemed to have this same problem with my doors. Hard to pull shut and would fly off the tracks. Check to make sure the wheels are in good shape and the tracks aren't bent. They can easily be bent back into shape with a screwdriver. Then I used WD-40 and sprayed on the tracks to make the door glide easier and I haven't had any problems since.
