Newer dump beds have a leg that folds down but most people never use them and they are usually rusted into place. Most people don't even know what it is for. I have never seen one on a older truck like ours, so I made one out of a pice of square tubing 2x4. notched the end to fit into one of the stringers in the bottom of the dump body and the other side is notched to fit the cross member on the frame (just rests there) You are correct in assuming you should NEVER work on a dump in the up position (especially with any load) without it braced. I see people doing it all the time and I cringe when I see it. We had a guy killed here too a few years back. Any thing to brace it incase of a failure.
