I obtained this bass for my son to (hopefully) play. Neck is nearly straight and looked like with a minor setup would be a good instrument to play. Took out the truss rod nut (looked similar to a Fender bullet nut), cleaned it and tried to put it back in but it wasn't going in. It looks like the threads on the rod were never there and the nut was never on the rod. Am I looking at replacing the truss rod? If so, is the best method to remove the fingerboard?
First off, the bass is not worth the repair, but you weren't going to get paid so let's move on.
I would approach this as if the truss rod had broken: Here is something to read: http://www.frets.com/FretsPages/Luthier/Technique/TrussRods/BrokenR...
And here is something to buy:
From a practical point of view, you might want to get your son another inexpensive bass while you're doing this repair. or you could look for a cheap neck and try to do a transplant, though a cheap left handed neck might be somewhat problematic.
or something like this: http://www.rondomusic.com/GBRose1kPPBLH.html, though I would go for a long scale myself.