Sliding doors don’t slide… they roll. And, the rolling part is a main factor in all patio door problems including drafts, misalignment, loose handles, scraping noises and dragging.
The secret is hidden in the base of your sliding patio door. In a slot or wide groove (out of sight) in the bottom horizontal frame of the operating door (the one that moves) are a pair of adjustable steel housings, axles, bearings and grooved zinc plated steel wheels called “rollers”. (Some can be nylon or stainless)
In the first twenty years of life, these roller assemblies deteriorate… the zinc plating wears and the metal rusts, the bearings wear and reduce (or stop) wheel rotation. The axles wear and can allow the door to shift and scrape the track walls… and the concave groove in each roller can flatten and create a misalignment of the door and gouging of the track rail.
As the above conditions gradually become more severe, the door becomes more difficult to move, the handles can break from the strain and drafts are common. It is not that the door is heavy or old… it’s the rollers!
When the rollers don’t roll, then the door “slides”… and, spreading grease or oil on the track will give you some relief for only about a day or two.
Bottom line, you just need to change the rollers.
There are over 300 different types of roller assemblies for the many patio doors that have been manufactured over the last 50 years. Some door rollers are extinct and new versions need to be skillfully retrofitted.
Regardless, changing the rollers is very cost-effective and is typically less than 10% of the cost of a new patio door system. This only needs to be done every 15-20 years.
Because of the various conditions caused by roller failure, just changing them may not completely solve all the issues. Therefore, someone with inexperience may find themselves in over their head.