Tried to upload a video but couldn't so put it on youtube.Check front control arm, hydro bearings and anti roll bar links first.
Possibly is that but I can't seem to see any play in it. I'll try and have a go at it when I've got more timeI think you might have found the problem. It is joint that have play or the section with bolt. Maybe you could tighten the bolt to higher torque.
Thought it was sorted when I took it in to have work done on it. Had the front wishbones, track rod ends (which they said would cure it) replaced, also had a new radiator and water pump done, as it was bowing, but still the knocking is there only slightly less so.Did you get this sorted? If you did, what was it?