New Alternator-Old mounting bracket doesn't fit?

Discussion in 'Troubleshooting & Diagnosis' started by wdstamper, Dec 29, 2017.

  1. wdstamper

    wdstamper Veteran Member

    115
    2
    May 17, 2014
    Florida
    Has anyone run into this issue before. I purchased a new alternator but the bracket's nut for the back of the alternator is way off. I can cut the mounting bracket and make it fit but that seems crazy. There should be an alternator out there somewhere that fits. I checked Summit, Autozone and Advance and they all have the same alternator attachment points. See pics below? Maybe I missing something. Thanks. Walt


    Alternator pic 1.jpg


    Altermator pic 2.jpg
     
  2. 70lt1z28

    70lt1z28 Veteran Member Gold Member

    2,325
    336
    Oct 3, 1999
    Beavercreek, Ohio, USA
    The housings are not "clocked" correctly for you. You can take the 4 bolts that hold the alternator front-back housings together and rotate the back housing in relation to the front a quarter turn. Put the bolts back in and your good.

    Don't pull the housings apart. There are spring loaded brushes that will snap out and you will have to fuss with those to get it back together.
     
    Cardinal likes this.
  3. wdstamper

    wdstamper Veteran Member

    115
    2
    May 17, 2014
    Florida
    70lt1z28:
    Thanks for the help. I will give it a whirl and let you know how it works out.

    Walt
     
  4. wdstamper

    wdstamper Veteran Member

    115
    2
    May 17, 2014
    Florida
    70lt1z28:
    The clocking was pretty easy; however, it did not fix my problem. It moved the alternator plug in under my bolt bracket which will not work (see pic below). Spun it the other way and still the bracket would not line up. I'm stumped at this point and think I will just drill the bracket with a hole for the new location and cut off any excess bracket if needed. Thanks for the help.

    Walt

    Alternator Pic 4.jpg

    Alternator pic 3.jpg
     
  5. FlaJunkie

    FlaJunkie Veteran Member Lifetime Gold Member

    6,073
    113
    Mar 24, 2001
    Rockledge, Florida
    I had the same issue I think. Let me look in my build thread and see what I did.
     
  6. FlaJunkie

    FlaJunkie Veteran Member Lifetime Gold Member

    6,073
    113
    Mar 24, 2001
    Rockledge, Florida
    Update 26 Oct 2011

    Everything takes much longer to do than it should. This hit me again
    today when I fitted the alternator to the motor. The bracket in the
    back doesn't fit the newer alternator I am using.

    I could have just let it go...but I made an extension to the bracket.

    [​IMG]

    [​IMG]


    [​IMG]

    Installation fit check...


    [​IMG]

    [​IMG]
     
  7. wdstamper

    wdstamper Veteran Member

    115
    2
    May 17, 2014
    Florida
    FlaJunkie:
    That's a good idea. I can clock it the other way and weld your extension idea on and drill. I may just drill and cut where its at. Not sure yet. I need to see which way looks best. Thanks for the help!

    Walt
     
  8. 70-camaro

    70-camaro Veteran Member

    1,607
    262
    Mar 25, 2010
    marietta ohio
    You could always return the new alternator and have the old one rebuilt. That’s what I did.
     
  9. DrPepper

    DrPepper Veteran Member

    112
    19
    Aug 29, 2017
    Central VA
    IMO you have the wrong alternator. I had the same problem w/ an Alt I got from AutoZone. According to their computer, the one they gave should have worked. But it was smaller than the original. I 'finally' found an employee who knew which Alt I needed. After I got the replacement unit, ALL my brackets fit as they should.
     
  10. McCune

    McCune Veteran Member

    865
    129
    Aug 22, 2015
    st.george utah
    Your original alternator is a 15 SI and you are trying to bolt on the smaller 10/12 SI. Tell the goof balls at the auto parts store you need a Lester number 7137. that is the factory 15 SI 70 amp alt.
     
    twozs likes this.

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