I have a Columbus F370FL and It was sent back to the factory in January to have all the walls removed and the body frame re-welded. They put new walls on but did not install expansion joints on the corners of the front slides over the king pin. This has caused the corner area to start to get hair line stress cracks normal on 5ers. I want to now install expansion joints but don't know the name and cant find the part used to cover the joints. Before they took it in it had such joint installed they were just in a hurry to get it back to me and did not install them. Can anyone help?