Instead of replacing it straight away, try putting on 2 or 3 trussrod washers. This will give you a few extra turns and usually solve the problem. It's a standard fix and costs only pennies (well, couple of quid probably).
Just undo and take off the trussrod nut, place washers over the rod thread, then put the nut back on and slowly tighten it to the ballpark of where you had it before, gently flexing the neck straight as you do to take the load off the trussrod as you go. Fine tune from there.
Hope that makes sense!