T5 swap speedo problems

Discussion in 'Drivetrain' started by SN90FiveOh, Jun 26, 2015.

  1. SN90FiveOh

    SN90FiveOh Active Member

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    Ok 5 speed swap is done and running pretty good for now. My car is a 2000. The t5 I installed is from a 98. The trans harness is out of the 98. I know that the speedo will be wrong until I calibrate it, but as of now when I am driving slow it jumps from 0-20-0-20 or what ever speed it thinks im doing until i get the gauge cluster to around 60 mph. Ive replaced the speed sensor and the plastic pickup gear looks fine. Ive heard about the vss vs oss but i dont know why mine is bouncing around. HELP!
     
  2. lutter94

    lutter94 Well-Known Member

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    I believe they're both the same Vehicle Speed Signal but the 99+ have a purely electric pickup, a whole different calibration. Is it consistent once you hit 60? How far off is the calibration? I know when I put a 99 T5 into my 94, my speedo read roughly 4-5x higher than the gps. So I would presume you would be reading extremely low. The trans harness should be fine. At this point I would recommend the Ford Racing SpeedCal, and attempt to fine tune it with that.
     
  3. SN90FiveOh

    SN90FiveOh Active Member

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    it only jumps 1-5 mph once i get around 60. My speedo read half of my speed at first but i fixed that with my tuner by turning the gear ratio to 2.73 then turning the tire rotations per mile down a bit. now it reads 60 when im doing ~40 so i dont need a speed cal just need to change the ratio some more.
     
  4. lwarrior1016

    lwarrior1016 Moderator Staff SN95 Supporter

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    Check this out. Its a little bit different than your situation but same concept.
    http://www.allfordmustangs.com/forums/4-6l-tech/869841-98-transmission-swap-02-transmission.html
     
  5. SN90FiveOh

    SN90FiveOh Active Member

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    hes going the other way around 98 to 02 and he didnt use the 02 harness. Im just confused because the speed is reading correctly it just keeps going to zero as if it loses power constantly until i get to a higher speed.
     
  6. 87hurricane

    87hurricane Member

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    Are you sure all your wires are good? It may just be that the signal your dash is receiving is different enough that the speedo isn't capable of converting it. Not sure if it will fit, but maybe it would be worth picking up a harness and speed sensor from an 02.
     
  7. SN90FiveOh

    SN90FiveOh Active Member

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    02 harness fixed it. Sorry haven't been on in a while.
     
  8. Mustanger

    Mustanger Well-Known Member

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    Thanks for coming back & letting us know what the solution was! LOL...I hate being left hanging!
     
  9. 87hurricane

    87hurricane Member

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    Yeah, glad you got it fixed. I wonder if you had a bad wire, or if the wiring is different?
     
  10. SN90FiveOh

    SN90FiveOh Active Member

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    The pinout 's are a little different and one is missing an 02 sensor.
     
  11. 87hurricane

    87hurricane Member

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    Oh, yeah that would do it. Thanks for satisfying my curiosity.