Our sliding closet door started burping up ball bearings due to a very slight bend in the lower rail and now is off the track.
What is the best way to get it back in the track? Will it require a new glide?

The best way to get it back on the track is to remove the bottom guide that is screwed to the floor and then pull the tracks toward the center of the trailer and start the first roller on the track. then push the door to the side of the closet. You may need to take out the stop that is between the upper guides to do this. I became a pro t it as our door was falling off every time we moved, as the stop between the 2 doors wasn't doing its job. Good luck.