[shorod]

Is it actually bottoming out or just making a loud clunk noise? First thing to check for that would be to make sure the front end is tight and you don't have worn suspension or steering joints. Also make sure the wheel bearing is not loose. If everything seems tight, then you might simply have a (common) anti-sway bar end link that is failing or anti-sway bar bushings that are worn. It could be a worn strut plate/mount as well but I've seen a lot of these get replaced only to find the problem was the end links. The strut plates are more difficult to change out too. End links and worn strut plates are not as much of a safety concern as they are a noisy nuisance. You certainly want to inspect the safety items first though.

-Rod