Speedo fix for using other than the 8.25

Discussion in 'SFA KJ' started by tjkj2002, Aug 13, 2009.

  1. tjkj2002

    tjkj2002 Full Access Member

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    I have finally fiqured out the speedo issue for using a non-8.25(or JJ's KJ 44) rear diff and a t-case that can use a mechanical speedo drive.

    By now you all know that Ted and myself are using AtlasII t-cases and a D60 and Ford 9" rear ends for our SFA swaps.Well the speedo issue has been kinda a black plague for us,planned on using a TJ electronic speedo drive and then having to wire it up(KJ uses 2 wires and TJ uses 3 wires) all with a speedo signal interface.I have been researching it alot and finally got in contact with Nevada Speedmeter,they are very knowledgeable poeple there and new exactly what the KJ used and a TJ.Well the KJ uses a AC signal generator and the TJ uses a Hall-effect sensor and are not adaptable.They make a little gismo that attaches to a regular mechanical speedo drive(will post part# when I get it,$160) and is the same AC signal generator that the KJ uses(2 wire) but of course I'll still have to adjust the pulses per mile by the Dakota Digital recalibrator(which I already have) to dail it in instead of uses different mechanical gears.Costly little bugger but cheaper then trying to machine stuff in the rear diff to use a tone ring and messing with all of that.

    This info might be usefull to any other person wanting to do a SFA swap and not have to worry about keeping the 8.25,finding a South Africa KJ D44,or machining the gears for a tone ring.Though use of the stock KJ t-case can't use this mod.

    Well here is the AC signal generator from Nevada Speedometer,screws on top of a mechanical speedo drive assembly.........

    Part# SA-2650-A
    Model# MGO
    Price---$160 plus S/H
    [​IMG]

    All parts needed...............
    1-Jeep/Chevy trans/t-case sleeve and retainer(mechanical speedo drive),can only get used
    2-Dodge/Jeep drive gear,short(any tooth count)
    3-WoodWard A/C signal generator,part# SA-2650-A
    4-Dakota Digital speedo generator calibrator box,part#SGI-5

    #1-#3 can be bought at Nevada Speedometer-1-775-358-7422(no website)
    #4 can be bought from Dakota Digital

    All totaled cost me $284 + S/H
     
  2. tjkj2002

    tjkj2002 Full Access Member

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    For anyone that is wondering the preliminary tests on this proved it works,I couldn't get no official tests due to not having a rear diff or driveshafts but the speedo works and I haven't fried anything yet.
     
  3. texasman1383

    texasman1383 New Member

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    Is it possible to run a jk d44 in the rear end of a kj?
     
  4. tjkj2002

    tjkj2002 Full Access Member

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    Yes but it will be considerably wider then the front by about 5" or so(2.5" perside) and you will need to swap in a different t-case also and use the above info to get the speedo to work again(the JK's D44 ABS sensors will not run your speedo correctly).
     
  5. jnaut

    jnaut Full Access Member

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    :eek:

    I have pretty shoes.