you guys were right. i didn't build the trailer and it is a 37" 500gal propane tank on a 72" trailer. i took it to a pro trailer shop i've used for my boat and they said the axle was fine and the spring still had 50% left, but they recommended just upgrading to a 2500lb spring on the tank side to level it all out and not have to worry about spring compression. got the spring but didn't add it today. instead i made a nice looking air inlet door like k.a.m. with the saw tooth locking lever. looks sweet and operates well too. this is my first welding project and I just love it. something about red hot metal and burning a hole in my coat; great fun! (i did get a nice leather welding coat this week to avoid future clothing fires!)
i'll take some pics of the b4 and after to help out any others too. thanks guys!