Fleetwood, who manufactured Coleman pop-up campers for a number of years, was notorious for using inferior plastic parts for the two types of caps on their bunk-end bed slide rails.

There is a wedge that faces the interior and helps to keep cords and the tenting material out of the way and there is the cap that faces outward that helps prevent snags but more importantly, keeps the bunk-end from sliding right on out of the camper.

Many people report that their wedges have broken. My situation was the outside-facing end cap. How I noticed was that the bunk-end would extend further out than the edge of the camper's lower wall when it had previously lined up. Upon inspection, the plastic ends were broken on both rails and needed replacing.

While they are not expensive, I did not want to use another set of plastic OEM end caps but I also did not want to spend the amount of money being asked for the third-party options. I decided to make my own from left over aluminum stock from previous projects (see https://pbase.com/ebond/camper_carrier for that).

Below are shots of what I did. It is not a perfect match but using only basic power tools, it works out pretty well. I did clean up and polish the final product before installation as it is quite rough in these pictures.

This little project was:
1) about saving money
2) making a stronger part than the OEM part that failed
3) getting to do a little more metal work (not into welding...yet)
4) enjoying some time tinkering and seeing if I can solve yet another problem
Mission accomplished.