J-neck on P-bass - Question

Discussion in 'Luthier's Corner' started by erik II, Mar 9, 2003.

  1. erik II

    erik II

    Jul 11, 2000
    Oslo, Norway
    I have gotten hold of a Jazz neck, and I want to mount it on my P-bass. However, the original P-neck is 20 frets and cut straight, while the J-neck has 21 frets, the RW fingerboard protrudes a bit. Here's an illustration, bottom fig. shows original neck:


    My question is:
    - Can I cut the excess 8mm off the J-neck without coming in conflict with the truss rod inside? In other words: How far in from the end is it to the truss rod anchor? See fig.A on illustration.

    Alternatively I can mount the J-neck as it is (fig.B), but then I'll have to move the bridge.

    I don't want to modify the neck pocket.

    Any comments and suggestions are welcome.
  2. rllefebv


    Oct 17, 2000
    Newberg, Oregon
    That type of neck, with the fingerboard extension to add an extra fret, is usually made to bolt into an existing, standard neck pocket. I'd definitely try mounting it before doing any kind of cutting!

  3. Turock

    Turock Supporting Member

    Apr 30, 2000
    I believe rllefebv is right. If you had 21 frets without an extension then you would have a problem, or if they are both genuine Fender necks then you may have a problem, otherwise it should bolt right on without any modification to the neck, body, or bridge (assuming that it is a direct replacement neck).
  4. erik II

    erik II

    Jul 11, 2000
    Oslo, Norway
    Thanks guys. This is a not-so-expensive Korean neck, don't know the brand. But I also believed it would fit directly.
    But with neck ends aligned, as the top and bottom figure has, the 20th fret on the J-neck will end up approx. 8mm further from the bridge than on the original neck, as the center line indicates.

    I have done some more measuring though, and it seems I can mount it without cutting it or moving the bridge. I'll just move the bridge saddles towards the neck to compensate for the fret displacement, there is enough space on the bridge plate. Just have to get some longer adjustment screws for the saddles. :)
  5. Heh I have it the other way around...P neck and J body...no tips apart from what the other guys said, if it's a replacement nec with extra 21'st fret, it should fit...
  6. erik II

    erik II

    Jul 11, 2000
    Oslo, Norway
    Thanks for bumpin' this ob1 - I think I've found a solution, but there's a couple of things I'd like to know:

    - Ref. original post: Does anyone know roughly how far in from the neck end the truss rod is? 1/10"...? 2"...?

    - What thread dimension are the saddle adjustment screws most likely to be? It's an '83 P Elite II. I don't have a thread gauge for Unified-threads (do you call them that?)...
  7. Is the trussrod "headstock adjustable" i.e. you pop a lid on the headstock to adjust the neck? Most fenders (all i've seen) are adjusted at the body. No way of telling how deep it is, if it's made like that.

    The saddle screws should be available at any musicstore, otherwise you can get a new bridge and use those screws (i ordered a "vintage style bridge" from Rockinger and the srews are plenty long :)).

    Are you sure that the heels are the same width? I have a Framus Jazz Bass that looks like a standard Fender copy, but the heel of the neck is slightly thinner, and longer.
  8. erik II

    erik II

    Jul 11, 2000
    Oslo, Norway
    The truss rod is adjustable from the headstock side. I just thought that someone who had either built a neck from scratch or "dissected" one could tell how far in the anchor would most likely be. The neck heel width is exactly the same as the original.

    I guess I could get some longer screws from the local music store. But I like to buy from a specialized screw vendor, where I can specify screw type and length myself.