Transmission Governor and physics

Discussion in 'The "Juice Box"' started by matt68gs400, May 21, 2019.

  1. matt68gs400

    matt68gs400 Well-Known Member

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    I refuse to watch TV in the summer. So I came up with this thought process on the transmission Governor using some physics equations; the centrifugal force equation and the spring equation. thoughts?
     
    Last edited: May 21, 2019
  2. BRUCE ROE

    BRUCE ROE Well-Known Member

    Some clever mechanical engineer worked out all the details. I have yet to
    hear a good way to relate the 1-2 and the 2-3 shifts. Anyway with my 2.41:1
    axle can do 60 in low, 100 in second, do not care much about the 2-3.
    Bruce Roe
     
  3. matt68gs400

    matt68gs400 Well-Known Member

    Me too. I’ve buggered up the shifting now in that it shifts too late in first and still too low of RPMs from Second to third. I have a few more ideas, weights, springs, and an extra governor
     
  4. Bigpig455

    Bigpig455 Fastest of the slow....

    Matt - Governor is on the way, looking forward to hearing how it works for you.

    You hit on an important point in your evaluation, one that most miss. Overall weight of the weight is not important, it's how much weight at the tip. I've always called it nose weight. Everything else is spot on too. They say that lighter springs bring the 2-3 shift up, and thats probably true. Trick is doing that without bringing the 1-2 shift beyond your RPM range...

    Here's a couple threads that might help you too...

    http://www.v8buick.com/index.php?threads/th400-governor-mods.305279/

    http://www.v8buick.com/index.php?threads/governor-info.207490/#post-1670863
     
  5. matt68gs400

    matt68gs400 Well-Known Member

    Thanks RT! i made that mistake with the springs and weights. I first ground a weight and got the 1-2 close to where i wanted it. Then I put in a smaller spring, which spread out the shifting a little but also increased 1-2. I got too aggressive with the grinding. I probably should have done the springs first, then a small amount of grinding on the tip, not so much on the sides.
     
  6. Matt69olds

    Matt69olds Member

    I have a large assortment of governors, I’m thinking about taking some of them apart and sorting and organizing the parts by weight. Does anyone in readerland have a chart or documentation on the different springs by colors, and their affect on shift points? Was B&M, TCI, etc thoughtful enough to follow the same colors and spring rates as GM? Thanks
     
  7. BRUCE ROE

    BRUCE ROE Well-Known Member

    I think of the weights as having more influence at higher mph, springs as more
    constat input. So perhaps adjusting the weights for the 2-3 shift, the springs
    for the 1-2 shift, back and forth a few times may get you what you want.
    Harshness and moving both shifts with the vacuum modulator.

    The governor does not see engine rpm, but driveshaft mph. Changing the
    axle ratio would change the shift mph, but not the engine rpm.

    I bought some long skinny cotter pins to replace those nail weight pivots.
    The C clip shaft in the weight kit stays there for the next car. I have sorted
    10 different spring strengths, by pushing 2 together on a 1/4 inch rod.
    Bruce Roe
     
    matt68gs400 likes this.
  8. matt68gs400

    matt68gs400 Well-Known Member

    I have heard that the colors are unique to each supplier, so they don’t match up.
     
  9. Bigpig455

    Bigpig455 Fastest of the slow....

    they dont- I measure spring tension in grams at .200 compression, and the springs from TCI, Shift Tech and B&M are all different. Also, the nose weights and overall weight of each kit's weights dont always correspond either. For instance, some of their heavier weights have very light centrifugal nose weight for the mass....very strange manufacturing.
     
  10. matt68gs400

    matt68gs400 Well-Known Member

    Is that grams per 0.2 mm? I see spring companies have stuff rated in pounds per inch for the English units. Haven’t checked out the metric
     
  11. Matt69olds

    Matt69olds Member

    Ok, since the aftermarket stuff is different, is the factory GM spring calibration consistent across the production? Meaning a orange spring from a 68 Cadillac is the same spring specs as a orange spring from a 90 Chevy truck? For that matter, are there any identifying marks or stamping a on the factory weights?

    I’m guessing there was probably a governor “recipe” book or documents at Hydromatic for all the different governor codes or applications. I work at the Chrysler Kokomo Transmission Plant, when I hired in 22 years ago there were some old timers who worked on the test garage, and the valve body Dept. They had papers for all the Chrysler rwd transmission calibrations back to the early 70s. I’m willing to bet Hydromatic has the same. That would be good info to have. Unfortunately, that stuff probably ended up in that big wastebasket in the sky it pains me to see the stuff this place throws away for model changeover.
     
    matt68gs400 likes this.
  12. BRUCE ROE

    BRUCE ROE Well-Known Member

    If you have a lot of springs, they are easily sorted into increasing strength. Just
    slide a couple onto a 1/4 inch rod, push them together, and see which compresses
    half way first. This can sort every spring you have into an order. If some are known
    numbers from a kit, you will know more and probably find some in between springs
    as well.

    When I find the weight (from a kit) I want, I then grind down a factory weigh to the
    same performance. It stays in the car, the numbered weight goes back in the kit.
    Bruce Roe
     

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