Looks like you have found the problem, but what to do to fix it...that I really can't tell you. Dealing with big truck steering boxes, they have an adjustment on them, but once you go there, the box is usually on it way to being bad...can't say that about these boxes, but I didn't see anywhere to tighten it while under mine today. There isn't anything along the steering arm leading to the box that would be loose is there????