I made a towing bar to pull my flatbed trailer around. Works fine, but how can I keep it from raising up if I put a load on the back of the trailer? Kubota L2550.
Cheap/easy way is to run a HEAVY ratchet strap through/to the trailer hitch (guessing you have one below the rear frame) and to both sides of the drawbar then tighten the ratchet strap when you get the height set. I think you can purchase adjustable check chains. Forward weight load on the trailer, secured, is a given....careful on hills, backing, etc. Try to keep the trailer tongue below rear tire axle height. Consider the weight of trailer/load vs the tractor weight. Common sense, etc...
