Hi Capt Ron,
Glad you came out of this without an accident. We have seen this issue before on 4" channel iron A frames. The issue has shown up on some of the 5,500 GVWR and 7,000 GVWR campers. The issue points to a 4" channel iron campers, but it takes more miles, the floor plan, the use of a WD hitch, the size of the WD bars and the loaded tongue weight and how many miles. Here is the original T2499 thread, which early failures due to the higher loaded tongue weights and the 4" channel A frame https://www.sunlineclub.com/forums/f...99-a-9326.html
The 2004 T2499's had 5" channel and so far they have not had an issue as reported here on the forum.
The issue is magnified when using a weight distribution hitch on the 4" channel combination combined with heavier loaded tongue weights and mileage. The size of the WD bars rating is part of this. The 4" channel twists in a turn when the WD chain or L bracket pulls on the 4" channel. That twisting A frame channel acts on the header connection. Over time, the flexing shows up bowing the center of the header followed by stages bending the battery tray angles. And if the problem is let go long enough, the 4" channel separates from the header. By your pics, the advanced stage is the A frame cracks apart. I have not seen this before.
I have a 2004 T2475 project camper that has this issue, just it was not as progressed as yours. I did see and point out to another club member on their 2007 T257SR camper their header was bent, which was the early stages of the problem. They added reinforcement before the problem became worse.
My 2004 T2475 header cracks shows up in this post, (scroll down for the header pics)
And this one shows the repair.
I have seen this myself show up on a 2005 T2363 I inspected for a friend. The 4" A frame channel was separated from the header.
I have a 2004 T1950 with the 4" A frame that uses a WD hitch, this one was not bent, but I reinforced it as a pre-emotive move. See here for more, https://www.sunlineclub.com/forums/f...tml#post155068
By chance, do you have any more pics of the header to 4" channel connection?
Can you share what size WD bars you have?
Do you know your loaded camper tongue weight?
Sunline was working through a fix to this issue before they went out of business. There was 2 iterations of the fix. So far, those few with the final fix, we have not had reports of them failing. I'm not sure if your header 4" channel has the last fix installed on it. That would be good to know. I can tell with more pics of what yours looked like if it was the first iteration or the second.
We are just trying to piece togther the combinations what aggravates the problem more, so folks can be better on the look out for this.
Thank you for sharing this with us. It is helpful that we can alert others to look for the signs.
Camper frame checks and suspension checks should happen annually. Both have shown to be a concern as the camper miles add up and miles towed increase.
Hope this helps