Setting action/relief on a Jazz Bass

[Reindeer]

I'm having an issue setting neck relief on my MIM Jazz. I'm turning the truss rod at the headstock counterclockwise, but nothing seems to be happening. And yes, I did take tension off the strings before I adjusted it.

 

[Jefenator]

If you're not feeling any resistance as you turn, it could be that the nut isn't pressing up against anything. If that's the case, the truss rod is as loose as you can set it. More counterclockwise turning would just move it farther up the rod.

 

[Reindeer]

That's what I'm afraid of. The neck has enough bow to it I have to keep the action way high or it has terrible fret buzz on anything above the 9th fret.