From time to time there are a rash of questions about front end clunks after replacing the strut cartridges. I had that problem and finally found the cause. I had not tightened the nut which holds the cartridge in the strut enough. I could have sworn that I did. When I replaced the cartridge. I tightened the nut using a large pipe wrench. I was so sure it was tight I kept looking for other causes for the clunk. Finally I jacked up the car and put the pipe wrench on that nut. I was able to get from 1/4 to 1/3 turn on the nut and that was all it took to stop the clunk. Maybe this will help someone else with the similar problem.