CV Pronblem?

I replaced the CV joints on the drivers side of my 88 jetta as the knocking noise when I turned was getting worse by the day. All seemed to go well in the next few days of doing some city driving. Today after coming off the freeway It started knocking bad and increased the faster I went. Now I wont hear it for 10 miles or so then it will start up again then disappear. Any Ideas?

check the bolt where it joins the tyrod to see if it got loose