rattly truss rod (I think)

[alyctes]

I have a Yamaha BB400F which has a rattle when played unamplified. 

I believe (from the sound and feel) this is probably the truss rod. 

How worried should I be, and is it fixable?  Thanks

[T-Bay]

Have you tried adjusting the truss rod? Is the nut loose? May just need to be nipped up and adjusted properly.

[ikay]

Have you tried giving the trussrod a gentle tweak to see if the rattle goes away? A one-way trussrod generally only rattles if it's loose - a small tweak to make sure it's engaged might be worth a try. Also worth checking that the rattle isn't coming from the tuners.

[Happy Jack]

The last time this happened to me, it turned out to be a slightly loose 'elephant ear' on one of the tuners ... nothing to do with the trussrod at all, despite what I believed. 

[ikay]

I had one of those too, took me ages to work out what it was!

[Grangur]

Elephant ear: me too.

The other thing to look at is uneven frets, if it's the strings rattling as you play.

[kodiakblair]

Had the elephant ear as well. Jammed a bit cardboard in the join, job done 

[alyctes]

Thanks gents.  It's fretless, so I'm reasonably confident in ruling out fret rattle  

I'll have a tweak of the TR and a careful listen to the tuners.

[yorks5stringer]

I had the same issue, tried everything and  narrowed it down to the truss rod. If I rapped my Knuckes on the neck you could hear it rattling. Unfortunately I sent it back to the shop to check out, they sent it back to Fender ( w/o my permission) and I lost the Bass. Tweaking the truss rod made no difference ( and it still worked) but I was prepared to inject some silicone down the channel to see if that would damp it yet not render the rod unusable. The other option was to tease out the central dot marker, carefully drill down to the rod and inject more silicone there too, fill and  then replace dot marker with a new one.