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Any Experiece With A Hall Speed Sensor?

Discussion in 'Early CJ5 and CJ6 Tech' started by jmoreau, Jul 23, 2016.

  1. jmoreau

    jmoreau New Member

    Has anyone ever used a universal hall magnet sensor to convert their speedo to any electric unit?

    Seems to me a few magnets on the ujoint of the rear prop shaft could make for some better accurate speeds than a jumpy needle on the old mechanical gauge.
     
  2. 47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    I have remedied the jumpy speedo by straightening out the inner cable at the transfer case. Take out the whole cable and lube it , make sure its not in poor condition or buy a new one. I have looked at GPS speedo systems, but they are not cheap.

    The rpm of the pickup would have to be calibrated to make it have the pulses it needs to indicate the desired interval, speed.
     
    jmoreau likes this.
  3. nickmil

    nickmil In mothballs.

    What 47v6 said. If everything is in good working order you won't have a jumpy needle. Might also do a search as this has been covered a lot with different fixes.
    Old school aftermarket cruise control kits used magnets like you describe. Very problematic. Not accurate enough for a speedometer in any case. If you want to go to an electronic speedometer either a gps unit or one that uses a sensor, commonly hall effect, that hooks directly where the cable would on the transfer case are much better options.
     
  4. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    I'm wondering why extreme accurracy is even needed.
     
  5. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    You could probably use a sensor through a diff cover aimed at the ring teeth but you'd need a pulse converter to get the speedo to read right, you might be able to gear something up (Pun Intended :D) using an arduino.

    Per the others if your speedo is jumpy you've got some kind of issue with the cable.

    H.
     
    jmoreau likes this.
  6. aallison

    aallison 74 cj6, 76 cj5. Has anyone seen my screwdriver?

    x2.
     
  7. Focker

    Focker That's a terrible idea...What time? Staff Member

    If he's anything like me...He just wants what's supposed to work, to work and to work right.
     
    Patrick and jmoreau like this.
  8. jmoreau

    jmoreau New Member

    Because when I do something, I want it to be right. Im not happy if its half-assed.
     
    ITLKSEZ likes this.
  9. jmoreau

    jmoreau New Member

    Yea, I believe the Autometer universal sensor calls for a 2 mile calibration and counting revolutions during that distance. Then its set. Curious on how accurate it is. Hard to find reviews on it.

    I may give it a go and make a writeup on it.
     
  10. 1967 CJ5A

    1967 CJ5A Mike 2024 Sponsor 2023 Sponsor 2022 Sponsor

    For a school project, I used a hall effect sensor and an Arduino to make a speedometer. I first used a LCD display, but then decided to use a servo instead to move the needle of a traditional speedometer. So what you suggest is possible. However, I think it would be easier to just fix the original system.
     
  11. Mcruff

    Mcruff Earlycj5 Machinist

    Bicycle speedometer works well and is accurate. There are also speedo gauges for ATV and such that work well.
    Trail tech is one of them that works good.
     
  12. 45es

    45es Active Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    The Autometer sensor / speedometer calibration calls for a 1 mile calibration. At least the one that I am using in my '45 GPW does. There is no need to count revolutions. The installation couldn't be any simpler. Install speedometer and sensor, wire the unit per enclosed diagram, find a measured mile and calibrate per instructions. Based on the highway mile markers and the speed of the others cars in traffic, it appears to be very accurate.
     
    jmoreau likes this.
  13. Warloch

    Warloch Did you say Flattie??? Staff Member

    I've converted two of my jeeps to speedos with the Hall sending unit. Put right in the stock location and just ran the wire. One mile calibration for them and it's good to go.
     
  14. Patrick

    Patrick Super Moderator Staff Member

    This. If it's there, it should work, work correctly, and work accurately. When you start letting things be half-assed, or don't fix things when they crap out, even little things, pretty soon the entire Jeep will be a half-assed piece of $h1T.
     
    jmoreau and ITLKSEZ like this.
  15. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    I agree, but in general that is easier if one keeps the stock conformation.
     
  16. Desert Runner

    Desert Runner Member 2024 Sponsor 2022 Sponsor

    I have been looking into this as well, I have replaced my speedo head 3 times, the original lasted from 1978 to 95. the replacement lasted until 2013 and the current one just died on my last Socal trip in April. I don't want to make a digital dash, I just want to stop buying speedometer heads.

    Jay