Update. After my last post, I went back out to try and see what else it could be. While hoping something would stand out. I noticed that the frame was broke right in front of the cross member and the bolt that holds the cross member to the frame was missing. The other side was good, although the bolt was loose. I welded up the frame, and put new bolts in the cross member, put all back together, and now it works like it used to. I guess there was enough separation in there to cause that. The crack was fresh, so I have to believe that was the pop I heard.
Thanks again for your help. Hopefully I won't be having to ask any other questions for a while.
Bob