Not only do they know about the problem, as they fixed my five year old unit that snapped a hanger and developed the frame cracks, using the Lippert procedure shown above....but the problem is they STILL build todays frames the exact same way they built mine...why the don't change their build procedure is beyond me.
My guess is no body has died from a broken frame. Hope it doesn't
come to that.
Just a thought but, is it possible that changing to LT tires from ST tires is part of the cause in this type of cracking? The side walls on LT tires are stiffer and do not flex like ST tires do. Could this extra stiffness cause additional stress on the I-Beam in a tight turning maneuver? I'm not saying this is the whole cause, but rather an additional contributing factor. Just a thought.
I had square steel bar welded across the trailer at the spring hangers this week so I now have some extra support in that area of the frame. In addition I had a 2" receiver fab'd up so I can carry my Honda Trail 90 or our bicycles with us.
Stiffer sidewalls would start stressing the frame earlier in the turn. But at some point, the side force on the tire is enough to overcome the friction between it and the ground and it starts to slide. At that point, you have the maximum stress on the frame. So it is a function of the amount of force it takes to get the tire to start sliding. That is independent of the sidewall stiffness.
The bar you had welded on is a simple solution. It would be easy for every manufacturer to include that. But they look to cut $50 here, and $10 there. So they put out what we get.
I some time think they design and build these things for a two year expected lifespan. Why do I think that? Because nothing on them other than the rubber roof membrane is warrantied beyond that. There are a few exceptions in the industry. Evergreen warranties their sidewall frames for three years on their Everlite line.