Help! What are these parts?
 

I dissemble the Sachs rear shock of my friend's EC300.
After pull up the damper shaft, I found three parts(ball, spring and screw) in the shock body.
I can not find them in the exploded diaphragm.
At first, I think they come from the top of the shaft but the screw is a little larger than the shaft.
Any idea?

This is the top of the shaft.

So I need to do some tapping to insert the 10mm hex cap in the 12mm hex sleeve.
Poor quality control⋯:mad: