Last night I was unhooking my trailer and just happened to look at the receiver pin holding my trailer ball and dropdown arm onto the receiver. The pin that has a lock on one side and a lets say "bushing" on the other side to hold it on place. The bushing was half way off. I pulled on it with a pair of channel locks and it came off with little or no effort. So the pin just slid right out. I always run with my chains hooked up but man--- I really think with 400 gallons of water that tandem trailer would have pulled my 3/4 ton chevy where ever it wanted to. I guess I was "BLESSED" to happen to look at it. I never ever look at it. I guarentee ya I am now. The only think I can think of is it was a 1/2" pin instead of the 5/8" pin that should have been in there. It must have been allowed to slide side to side with that 1/8" difference. My new one is a solid 5/8" with no sleeve.