I now have a set of tracks that work. What I discovered is that the original tread that I made and manually placed each one individually around the wheels and sprockets to create a track was the problem. When I created a motion path and attached one of those threads it went off the motion path. For some reason it didn't when I did a Create Animation Snapshot. The only thing I can think of is that the first tread was placed at the start of the motion path and it just happened to be sitting on the motion path perfectly and the Create Animation Snapshot copied that all the way around.
I then started my second set of tracks using a tread from the ones created by Create Animation Snapshot. They worked perfectly. The only thing I should have done was created the first track in the correct position on the tank not off to the side. Reason being the tutorial said you cannot move it after creating it or it explodes, which it did. So I had to do a Duplicate Instance twice and move them into position, hiding the original one. I'll know next time. I'm very happy with how they turned out. Now I need to get the wheels and sprockets to rotate with them.
Thanks for your help.