Hi, guys

My dishwasher has started a loud buzzing. From what I gather on this forum, food may have gotten caught inside. I've looked at the diagrams available, but I can't figure out how to remove the arms in the bottom of the tub. I see the grey screw (or what looks like a screw) in the dead center top of the arms, but when I turn it (either right or left) it doesn't seem to advance in or out. But I don't see any other way to remove the arms.

Any advice?

Thanks so much!