We replaced all the plastic ends of our rear motorhome ladder. Many were cracked and some broken. Very dangerous to use ladder with broken parts. Those creaks when climbing ladder need to be heeded.
Broken step mounting before replacement. Very dangerous to use ladder with broken or cracked ends. Care must be taken to examine each step end and those creaks when climbing rear ladder should be taken seriously.
Cracked ends may be difficult to see. Crack usually happens in center.
New step end. Note that it is the center screw that fastens each step end to the vertical part of the latter attached to the motorhome. New center screw is self-drilling and care should be used to make a new inside hole if original was not straight. Outer hole is always reused. I found several original center screw holes were put in at an angle where they did not exit the ladder across from entry hole in ladder. I redirected new self-drilling screw and made a new straight hole. If you can find the same screw head which fits the ends, stainless would work ok.