Rattling truss rod

[John_C]

My main guitar, an ESP LTD MH400 has developed a serious rattle on the bottom string (no it's nothing to do with fret buzz).
It's really nasty sounding and hard to place, i can hear it pretty evenly most of the way up the neck and the headstock

I presume it's truss rod rattle, what can I do to prevent it? I've tried adjusting the rod and then taking it back to it's correct placement but it makes no difference.

 

[JeffTD]

Knock on the back of the neck while holding the strings muted and you should be able to hear a distinct rattle from the rod - usually near the nut.

My old Tele neck and Stinnett's neck both have a certain 'sweet spot' where the truss rod would rattle, usually just took an extra 1/8 turn of tightening to get it into a spot where it would stay put. Try over-tightening a bit, and check for rattle at ever 1/8 or 1/4 turn as you go.