The rollers on this sliding patio door were so badly worn that they'd blown out the ball bearings, causing the one side of the door to drag along the track.
One pull in the wrong direction would have seen this door fall completely out of its frame and potentially flatten the user!
I removed it safely and removed the worn old rollers from the bottom of the door, replacing them with an up-rated design that spreads the load across four wheels rather than the original two.
Once re-fitted the door slid smoothly and was as good as new again with a few minor adjustments to the running height.
Another successful day working as a door repair specialist in Wolverhampton.
https://www.locksmith-in-wolverhampton.co.uk/patio-doors.html