Your not the first to have a problem and its mostly lubing the hinge because if not rust will cause the door to bind with the pins near your floor entrance.
Here is a
search of your problem in search in irv2 top of forum page, you can input any wording you like for more info.
You may find use of
this link also for many items in your coach plus the links in my signature.
Your thread may wake up some other owners of CS Toy Haulers that have run into same problem, or our THG in
this link.