These trailers were manufactured to have "dump" or "tilt" capability, breakage like that is from abuse, that will not happen under normal use/load. These trailers are only rated to haul 2000lbs in them of cargo, No way that would snap like that with 2000 lbs,
AND
Look at that spring, where the bolt goes through, it pivits on that front spring bolt, there hasnt been any maint performed or fresh grease added for decades.....
Way to get guys bent out of shape and worried, the original contract for these trailers required that they were able to dump or tilt for loading and unloading cargo....
I really have trouble believing that. I don't know why I didn't see it the first time I was going to set up an A1 for dumping, but I recognized it in this discussion.
When the drawbar pivots on those two bolts, it's assembly angle (not tilt angle) stays the same, while the spring mounts are forced to torque to follow the drawbar assembly's angle.
Those are cast spring mounts if I'm remembering right. Cast material breaks under torque like that, doesn't flex. I think these break because it's a stressful design when used for dumping, not because of abuse or overloading.
The idea solution for dumping is a ball joint on the spring mounts. But that means move the drawbar forward 3 inches and extend it rearward 3 inches to widen it enough to fit a ball joint, add a crossmember to the drawbar just before where it was extended, and weld in upper reinforcement to the spring mount. And then, since you're fabbing stuff up left and right, might as well put a hydraulic jack from another new drawbar crossmember up to the frame so you can further reduce the awkward lifting stress on the spring mounts and drawbar.
Kind of a pain in the arse...