When do you know you need to adjust the truss rod?

[moopants]

I have a bass that I've had for about 3 years, and I've never made any adjustments. It buzzes A LOT, and I'm sure I need to do something about it. But, I have a bass that I've only had for a year, and still didn't make any adjustments. It's fretless, so there's no fret buzz, but it makes that wood buzz tone more on the lower positions than anywhere else, and the bridge rattles slightly (noticable) when I play it. Do I need to adjust my truss rods?

[JimmyM]

Possibly. Capo the neck at the first fret and fret the G string at the highest fret, and see if it lays across the fingerboard flat at the 8th fret. If it's totally flat against it, it needs to be loosened a little until you have a tiny bit of bow to it. Do it slowly, no more than 1/4 turn at a time, then recheck and see if the buzz went away. If not, turn a 1/4 turn again until you get it. You shouldn't have a lot of bow, but just enough to keep it from buzzing.

You may need to adjust your action after you do this, as it will make your action higher. It's a pretty easy fix, but you may want to take it to a repair shop the first time and watch them do it to learn it.

[moopants]

Is it a turn to the right or left? I guess I could bring it to the music store to make sure I really understand what to do.

[JimmyM]

I have no idea what your bass is or how it works, but the general rule of thumb is "righty tighty, lefty loosey."