Cannondale System Six headset knocking

[Mr_Carlos]

I've recently stripped the headset down on my Cannondale System Six and cleaned, lubed everything. Bearings seemed ok. But I seem to have a knocking if I put pressure on one side of the bars.

Does anyone know of an assembly guide anywhere? I think there may be a small amount of movement in the reducer, I greased this but if it's not supposed to move should it be loctited?