Crazy speedometer

Discussion in 'Tech Discussion' started by 73c20jim, Nov 27, 2018.

  1. 73c20jim

    73c20jim Supporting Member Supporting Member

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    How can a mechanical speedometer be 10 MPH slow and the next day be almost dead on. GPS check.
     
  2. Matt69olds

    Matt69olds Full Access Member

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    I’m guessing either the gears inside the speedo are dry (grease dried out?) more friction, spins slower, or maybe temperature related? Cold speedo lube, more friction?
     
  3. 73c20jim

    73c20jim Supporting Member Supporting Member

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    Good places to check. Thanks.
     
  4. 1987 GMC Jimmy

    1987 GMC Jimmy Full Access Member

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    Or a crummy aftermarket cable. My speedos perform fairly well using a somewhat worn out, abused, 33 year old cable on the bench, but they do the same thing as yours in my car. I have yet to find a cable that even comes close to the OEM design. I’m on the verge of saying screw it and just putting the dinosaur cable back in.
     
  5. Westislander

    Westislander Full Access Member

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    [QUOTE="Matt69olds, post: 457076, member: 15079] ...
    Cold speedo lube, more friction?[/QUOTE]

    ....lube makes everything quicker
     
  6. Matt69olds

    Matt69olds Full Access Member

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    Oh great, is this going to make it to the square body quote thread?
     
    78c10bigten likes this.
  7. 73c20jim

    73c20jim Supporting Member Supporting Member

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    using OEM cable, at least it looks like oem cable.
     
  8. ali_c20

    ali_c20 Member

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    My speedo does the same and the faster I go the more accurate is my speedo. I have tried 3 different brand speedo cables and all of them sucked. If I ever find a good speedo cable that works as expected I'll post it.
     
  9. Byco

    Byco Junior Member

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    What about LMC speedo cable? works well?
     

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