How to Repair Rollers Under Sliding Patio Doors

Kneel down near the base of the sliding door as an assistant lifts up on the sliding section of the door. Examine the rollers near the bottom edges of the door.

Reposition the rollers onto the track underneath the door, using the shaft of a screwdriver to adjust them, if the rollers have jumped off the track. Slide the door closed and open, to see if it drags.

Locate the adjusting screw that is either on the bottom side of the door, or on the bottom door edge. Look for either one or two screws. Remove any cap covering each screw, and turn each screw completely counterclockwise, using a screwdriver.

Space two sawhorses apart, at a distance to support the door fully. Drape a sheet, for padding, over the sawhorses.

Stand inside the room, on one end of the sliding door, while your assistant stands on the other end. Lift up on the door and lean the bottom of it away from the door frame, towards you. Lift the door and lay it across the two sawhorses.

Inspect the rollers to make sure they are not damaged. Turn the screw on the side of the rollers clockwise to lower the rollers, using a screwdriver; or turn the roller screws counterclockwise to raise the rollers to a correct height. Scrape all the dirt from each roller, using a toothbrush. Pour alcohol onto a rag, and wipe the rollers down with the rag. Place a drop of WD-40 on each roller.

Examine the door track for dirt and grease. Remove any loose debris from the track, using a vacuum cleaner. Scrape out any stuck debris or grease, using a toothbrush.

Lift the door and position it so that the top of the door goes into the channel in the top of the door frame. Place the bottom of the door into position, with the rollers correctly in the bottom track. Slide the door open and shut to make sure it glides smoothly.