light steering?

focus 1.8 tdci 56 reg
replaced front wish bones and replaced drop links with heavy duty ones, and now when i drive through rain surface water the front end seems to go light/twitchy (don't recall it being like that brfore). ive checked all nuts and bolts, geomertry and all is fine, otherwise car drives and handles nice and true. i followed procedure stated in the haynes book. any ideas thanks.