Idk about that I just so happenly have my d1-4 spindle on the bench whole nother thread. 
So there is the cam lock, then there is the Allen key in question. I know it’s a terrible pic but the angle of the Allen key is intersecting right at the bottom of the cam lock. Which has a groove in it. The Allen pushes on a spring which pushes a slug with a groove cut on the end of it that interlocks with the cam lock holding it in place but allowing it to spin.
What else would the screws be for theirs nothing else on the spindle. And if you look at a parts break down it shows the spring and slugs. When In doubt always review the manual.
So there is the cam lock, then there is the Allen key in question. I know it’s a terrible pic but the angle of the Allen key is intersecting right at the bottom of the cam lock. Which has a groove in it. The Allen pushes on a spring which pushes a slug with a groove cut on the end of it that interlocks with the cam lock holding it in place but allowing it to spin.
What else would the screws be for theirs nothing else on the spindle. And if you look at a parts break down it shows the spring and slugs. When In doubt always review the manual.
