After reading a post about another Thor stairwell failing I decided to inspect mine .
I found the left side had failed .. creating a gap when weight is applied to step.
This is not noticeable upon entry or exit ... as you are looking up or out during use.
The surprising thing.. the engineered system here , all the weight of a person is placed on a corner screw, screwed into the motorhome floor, through a piece of 1/4” plastic. (See Photo) this sidewall of the entry box is hung from the floor.
There is steel struts and structure on either side which could had been used for support.
I really cannot believe every stairwell has not failed in every unit made.. they did use “big screws” lmao ... too bad the plastic can’t support 200+ lbs
I really hope this design has been corrected.. it’s going to be an easy fix... but no telling what a dealer would charge for this repair.
My fix will be to attach the bottom to the upper strut.. take all the weight off of the plastic box