Shouldn’t have been too weak. I’ve been using this cart under the dart since at least 2015. All 1/4 inch steel and gussetted. Casters are rated for 1045lbs EACH.
I’ll get a pic but it looks like the pivot pin that held the caster to the bracket worked loose and being that it is hidden, I just didn’t see it.
As for fixing it, nah. I was nearly done with it for its purpose anyway. Was planning on setting her down on all 4s next week before this happened. Just been waiting on tires for my 18s but I’d decided earlier in the week I was just gonna put the junk rims and tires I took off the Polara on to the dart.