It has a bedroom slide. The sidewall below the front corner of the slide has been cracked for at least 5 years. Without looking at the trailer which is in storage right now, I would say that is about a distance of 6 in. I covered this with a small piece of eternabond to prevent water damage. The trailer sits fairly level over the truck, so I am thinking the problem is in the pin box area. Also, this didn't just happen but I think the severity has increased. One thing I don't need is a total frame failure in the dead of winter on the way to Florida. I will bring it home and open the bottom up to have a look and keep you guys posted. Thanks for the input so far. This is a great forum for learning and problem solving.