When my car is idling and the gearbox in neutral, then when I depress the clutch and lift it to the regular engage point, there is a metallic knock from the gearbox/clutch. 

 

Anyone knows what that is? Fault? 

 

I recorded a video of the sound. 

 

 

Nothing to worry about in my opinion.

Possibly the clutchfork returning hitting the case then. Shouldn't the clutch slave dampen this when returning?

 

Haven't heard anything like this before. Worried that maybe something is loose inside.