I believe AL10453 has give you good advice. I had an older Adventure that had the same problem. I took it to a welding shop and they reinforced the mounting area for the steps. It was not perfect but much improved.
Don & Bev Morgan Weyauwega WI, 05 Itasca Horizon 40KD, 400 HP Cummins, Adopted by a great couple, Toad 07 Saturn Vue AWD, Air Force One, TST 510 TPMS, Mayor of Weyauwega 2007 - 2013, Waupaca Co Board Supervisor 2010 - 2014