older TTs with wheels on the rear frame/bumper

My Trail Cruiser sits very low to the ground, I have hitch ball height set as low as possible just to keep the trailer level when towing. I have about 16" clearance from the bottom of the frame to the ground at the back. I had scissor jacks back there but broke them off a couple of times so I moved them right behind the wheels. Now I just have a-arm stabilizers back there that don't seem to hit. The bumper has no scrape marks, but I go very slow and careful when I am close to touching ground.