GQ front wheel shimmy

Hi all,
is there someone out there in Nissan land that can tell me how to adjust
the swivell head bearings , I checked them to start with , they fall from lock to lock
easily by them selves .
I,ve taken out the 0.015 thou shim from each bearing and now they have prload on them but what is the right amount ??, they can stil be moved through there range of travel by one hand with not two much effort and they seem smooth in diong so .
good advice is much appreciated .
cheers mechpete.