512BB Distributor - Taking it Apart | FerrariChat
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512BB Distributor - Taking it Apart

Discussion in 'Technical Q&A' started by Drew Altemara, Jan 11, 2011.

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  1. Drew Altemara

    Drew Altemara Formula 3

    Feb 11, 2002
    1,537
    Tuscaloosa, AL
    Full Name:
    Drew Altemara
    #1 Drew Altemara, Jan 11, 2011
    I can't see where the distributor advance mechanism on my 79 512BB has ever been cleaned and regreased. I'm not getting any hesitation and timing light advance wise seem to be OK so this is just preventative in nature or I'm bored and have time to do it this weekend.

    From the searches I can't find a good tutorial or diagram on how to access the advance mechanism.

    Assume I have it off the car and have marked everything so I know how to put it back together.

    This distributor uses a pickup so no points to mess with.

    Here is how I think it goes:

    Remove rotor.

    Remove screws holding top spyder top on.

    Using a small puller pull spyder; can I use the top of the shaft to apply pressure with the screw part of the puller?

    Again using a small puller again, pull bearing up from the top; is this right?

    I have heard mention of a small "e-clip" that then has to be removed; what is this about?

    Then the shaft slips down the body so you can access the advance mechanism?

    Any help and any diagrams appreciated. Just want to have my battle plan ready before I have the distributor in hand and get stuck Saturday.

    Thanks,

    Drew Altemara
     
  2. Peter

    Peter F1 Veteran
    Owner

    Dec 21, 2000
    6,441
    B.C., Canada
    #2 Peter, Jan 11, 2011
    Last edited by a moderator: Sep 7, 2017
    Yes, there is a small C-Clip which holds the top bearing to the dist. shaft and yes, a small puller would be necessary as I find - at least on all of the dist.'s I have - that they're all a good fit on the shaft.

    Here's a part's breakdown of my points-based dist. from my GT4:
    Image Unavailable, Please Login
     
  3. Drew Altemara

    Drew Altemara Formula 3

    Feb 11, 2002
    1,537
    Tuscaloosa, AL
    Full Name:
    Drew Altemara
    #3 Drew Altemara, Jan 11, 2011
    Last edited: Jan 11, 2011
    Thanks Peter, that does help quite a bit.

    So after I remove the spider, remove the c-clip for the bearing, pull the bearing; I can remove the six or so screws on the bottom and gain access to the mechanical advance?

    Thanks for your help.

    Drew Altemara
     
  4. Peter

    Peter F1 Veteran
    Owner

    Dec 21, 2000
    6,441
    B.C., Canada
    #4 Peter, Jan 11, 2011
    Wait, if I remember correctly, there's no need to remove the top bearing when extracting the shaft from the dist. body. The hole in the middle is big enough for it to pass through.

    In any case, in order to remove the advance parts, that top bearing does have to come off, so you could remove it either before or after the shaft comes out.

    And really, this all depends if your dist. has that magnetic ring on the shaft for the electronic pick-up, that may need to be removed before you can extract the shaft from the body, so you may need to remove that top bearing for that...
     
  5. 335s

    335s Formula Junior

    Jan 17, 2007
    870
    SF Bay Area
    Full Name:
    T. Monma
    #5 335s, Jan 11, 2011
    This is potentially a case of making extra work for yourself...
    without the use of a stroboscopic distributor machine-most of us use SUN machines-you canot ck/set up the most crucial aspect of the job: Advance curves...
    proper dwell, phasing etc, all are best done at the same time on the machine as well..
    FWIW...
     
  6. britalian

    britalian Karting

    Feb 10, 2006
    64
    Atlanta
    Full Name:
    LL
    #6 britalian, Jan 11, 2011
    Last edited by a moderator: Sep 7, 2017
    Hi Drew,
    It's been about 6 months since I've built one so I may be a little fuzzy on some of the details (and by no means am I attempting any sort of tutorial) but to the best of my recollection... the S158 series does not have a removable top sypder like most other Ferrari distributors. To access the weight assemblies, remove the rotor button, remove the metal pin in the top of the shaft and remove the metal top plug. Under the top plug there should be a piece of felt and under that felt should be a screw that holds the trigger wheel / upper advance slides to the shaft. Remove that screw. Remove the screws around the bottom plate and the bottom plate with the shaft and the cup with advance weights should come out of the housing leaving the trigger wheel / advance slides in the upper bearing & still in the housing. Watch out for the shims between the two! Now you should have complete access to the advance weights for cleaning & lubing.

    I have attached a photo of the original parts sheet. It only really accounts for parts that could be ordered so not every piece is shown but you may find it helpful.

    Let me know if you want to come by or send it up to run on the Sun tester.

    Lee
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  7. Drew Altemara

    Drew Altemara Formula 3

    Feb 11, 2002
    1,537
    Tuscaloosa, AL
    Full Name:
    Drew Altemara
    #7 Drew Altemara, Jan 12, 2011
    Thanks Lee.

    Very different looking distributor design than the older ones with points.

    This really helps a lot.

    If I get stuck or if it looks bad once I get it apart I may sent it over to you to check the advance curve.

    Just trying to get my game face on for this weekend.



    Drew
     

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