I don't know if this is significant or not, but I was looking through my service manual at the way the fresh water tank is supported. One of the angle-iron pieces is held in with 1x1/4 self-tapping screws. The removal procedure in the manual doesn't mention removing the other 3 angles, so I don't know how they're actually attached (anyone else know? ). But anyway, that z-angle is holding up more than 1/4 of the weight of a full tank, bouncing down the road...well...maybe not. maybe the others are welded in place, and they're supporting all the weight. but anyway, I've looked at mine, and it doesn't look like its about to fall out any time soon