overloaded. it was not rusted inside the tube.
trailer is 10700 on the axles and the tongue feels heavy, so it's probably 1500-1800 tongue weight. that was factory hitch, just plain not rated for that weight. If it follows standard Class IV ratings it was probably 5000/500 or 7000/700 static, 10000/1000 WD - and I wasn't running WD.
New Curt Class V is rated for 15000 static 16000 WD. But that will be coming off as soon as I get the hauler bed. That has a built-in 10k rated receiver.