Terry, for some reason, your image didn't show up right on my computer at least. This is what I got.
As far as the lower mounts go, the arms are just mounted on a 5/8" pin with washers on each side to space it out to the keeper. There is no plate or tab on the outside. Maybe there should be, but with the washers there doesn't seem to be much side to side play. The pins do wobble a bit though. If I were to use it for a plow (which I don't have yet), I would probably have to add diagonal chains to help keep the arms straight. I have 23 10.50 12's on it in the narrow setting, and the arms are about 1" away when swung to the side. Bar tires might be closer, and chains would be out of the question with the tires in the narrow setting. I will be running my 6-12's with chains soon for winter and I may have to put them on the wide setting.
(Message edited by treed on October 25, 2014)