from the first pictures (see attached files “pict. base tube”) is clear that this is a case of side load.
In fact the base tube of cylinder has some scratches in the direction of pin due to the fact that the cylinder do not work straight.
The outer cover go against the base tube this means that the stages suffered of side load.
This usually happens when the final customer moves the truck with raised body or the load on the body is unevenly distributed and all these are prohibited by our user manual.
Moreover there is rust inside the hole (see attached file “Bracket”) of the upper brackets it means that it hasn’t been greased, in this way the outer cover has an high resistance during the rotation of the pins.