When loading custom size paper in Tray 2 or 3, use the following procedure to lock the end fence:
While pressing down on both sides of the end fence, slide the end fence until it is aligned with the bottom edge of the paper you want to load.
Hold the grip of the end fence and pull it upward, and then release it.
Make sure the stopping claws are extended and the end fence is securely locked.
When loading standard size paper, hold the grip of the end fence and push it downward, and then set it back in its original position.