What hex screw are you talking about? Is it the hex screw shown below: if not, can you please explain further on what to do?
I did tighten this bolt down and it still had room to go.
Also, I noticed that my Flex is really REALLY noisy and it vibrates a lot! It seems that the black piece in between the white part and the metal part is loose. (Shown in picture below) Even if I already tightened the bolt shown above. Is this normal?
Thanks guys!