Coilover question. What is the top thread for??? (tein)

[Shitbreak]

Pic attached. Anyone know what the bolt and thread directly below the adjustment screw is for?

Was investigating a knocking sound coming from the back, and noticed that the left had side coilover has possibly unthreaded itself downward to the point where there is hardly any thread left above the nut in the pic (arrow with question marks pointing to it).

The right hand side coilover has a similar thread length left as pictured.

Thoughts?

EDIT: Pic is not the actual coilover. Just some random pic I found on the internet.

[Shitbreak]

Never mind. I jacked up the rear and tightened the nut, and its all good. A lot easier than I thought

[AlexinPerth]

I normally use a rattle gun to do them up, or hold the flats on the shaft with a small spanner. Bit hard to use a rattle gun while they're installed though..

[dynoryder]

you cannot rattel up a externaly ajustableble shock it will break the top off