Don’t let a scraping, dragging door ruin your day. Let’s replace the rollers!
Before you start, clean the track your door runs on. Your door may be scraping or dragging due to being caught on something. Have a good look at the raised ‘rail’ the door roller sits on. If this is worn down too low, you’ll need a whole new door track, not just a replacement roller.
Removing the Door
Assuming the problem is your door roller - the first order of business is to remove the door. If it is a large glass door, it will weigh approximately 1 metric-shit-tonne. If you have help, use it.
Before removing the door, clear a space for it. It sucks to remove the door then realise you have nowhere to put the door down. It’s not a bad idea to put down a blanket to protect your floors. Metal framed doors can have sharp edges, and will happy scratch a deep groove into a timber or bamboo floor.
The actual removal process is fairly easy. Simply lift the door up into the frame - then (while keeping the door suspended in the air), bring the base of the door in towards you, as in the diagram below.
Once you have it out, lay the door on the long side. You’ll find a screw. This screw will either be attached directly to the roller assembly, or pulling the door frame tight and clamping the roller assembly in place.
Once you remove the screw, the roller assembly should slide out. Examine the roller wheel for wear and dirt. It may be worn down (you will need a new one). After cleaning any dirt out, it should spin freely. If not, you need a new one. If it does spin freely, it may have been sitting too high in the door.
If you need a new roller assembly, take the old one to a hardware store, and find the matching replacement part. Keep in mind that your house is missing a door, which will make it pretty easy for thieves - so hurry.
Replacing the roller assembly
Putting the new roller assembly in simply reverses the process. Pay careful attention to how high the roller is sitting before you put the screw back in and tighten.
The roller needs to be sticking out the door enough that the door will move freely without scraping. Too high and you won’t be able to get the door back in the frame. In my case, having the rollers protrude 3mm worked perfectly.
What about windows?
Window rollers are replaced exactly the same way - assuming you have modern sliding windows. The only difference is that a window weighs less than a door, so it is easier to lift out.