I'd a problem like this before. Clunking when turning corners and when I hit the brakes. What I found was 1 wheel nut was missing and 2 had been loose.. Needless to say I went out that day and bought lock nuts Sometimes it can be the simple things especially if it wasn't there one day and then the next time your out in the car all of a sudden you get a knocking.. Otherwise i'd check the anti roll bar drop links..