A good tip for wheel bearing adjustment that has always served me well is, once its all back together,put the wheel on and do it up well, loosen the castellated nut a bit,if you wiggle the wheel at top/bottom and side/side,you should detect a little bit of movement,tighten the nut up till this "just" dissapears,then,without it showing movement fit split pin as close to that point as you can .