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‘97 four cylinder swap to six cylinder

Discussion in 'Wrangler TJ (1996-2006)' started by auttiman, Sep 18, 2019.

  1. Sep 18, 2019 at 6:58 AM
    #1
    auttiman

    auttiman [OP] Member

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    hello all. I’m new here and wondering what is needed as far as frame modifications to install a 4.0 in my jeep where a 2.5 came from the factory. I have a 2005 low mileage 4.0 donor and plan to mate it to an AX15 (external slave).

    Anyway, the frame risers(?) where the motor mounts bolt to are the first issue. Will the 4.0 mounts bolt directly to them or will I need to cut and weld something else there?

    Any and all advice will be greatly appreciated!
     
  2. Sep 18, 2019 at 7:23 AM
    #2
    aggrex

    aggrex Well-Known Member

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  3. Sep 18, 2019 at 12:05 PM
    #3
    Prerunner1982

    Prerunner1982 Well-Known Member

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    Motor mounts are an issue, but the bigger issue is the wiring unless you have the complete harness and computer to go with the 4.0.
    Did your TJ have a manual transmission? If so you will need to source a transfer case from a 6 cylinder model as well as they have different spline counts.
     
  4. Sep 19, 2019 at 9:34 AM
    #4
    auttiman

    auttiman [OP] Member

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    I’ve got a harness and ecm and an ax15. Still looking for either an Atlas or a Tcase. I bought the TJ with the 2.5 only. AX5 and Tcase were gone.
     
    Prerunner1982[QUOTED] likes this.
  5. Oct 1, 2019 at 5:34 AM
    #5
    auttiman

    auttiman [OP] Member

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    Update. I found a free tranny (ax5). I’m either gonna put a new throw-out bearing on it and mate it to a 21 spline tcase (I’d have to rob it from my MJ) or get the advanced adapter kit that allows use of the ax5 bell housing mated to my ax15. Then I can use my 242-j Tcase mated to the ax15.

    Is there a heavier fly wheel or any other mod I should consider before installing the transmission?
     
  6. Oct 4, 2019 at 4:56 AM
    #6
    auttiman

    auttiman [OP] Member

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    Bump for heavier fly wheel for the 2.5
     
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