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Gyromatic Transmission

Discussion in 'The Hokey Ass Message Board' started by cody440, Mar 1, 2006.

  1. cody440
    Joined: Jan 15, 2005
    Posts: 54


    Can somebody inform me on Chrysler's Gyromatic transmisson. I was looking at a 1950 Dodge Coronet and I just wanted to know about them. How are they?

    -Thank You
  2. they're goofy. From what I can gather (don't quote me) the Gyromatic is pretty much the same thing as the Chrysler Fluid drive- that is, a dual range with high and low in each range. The Dodge Fluid drive is a three speed manual with a torque converter. I have also noticed (again, don't quote me) that it seems the prewar Chryslers were the dual range thing, and the postwar Dodges were the three speed thing.

    From a hot rodding petrspective they're all power robbing junk. From a reliabilty or driving perspective, well, opinions vary. Personally I hate the Fluid drive in my '50 Dodge, but it gets me to and from work every day. I have never driven a Gyromatic. I'm putting a 5 speed in mine SOON. I read once that the Gyromatic was deemed complicated enough to drive that it came with its own set of instructions in the glove box.

    confused yet?
    cody440 likes this.
  3. CruZer
    Joined: Jan 24, 2003
    Posts: 1,902


    I'm going way back now, but in 1956 I was 9 years old and my father drove a 1951 Dodge coupe with the gyromatic. It drove just like a stick but you could mash the gas to the floor and it would kick back down to second to pass cars.
    You could also start out in high gear without using the clutch but it took forever to get to 20mph.
    The car rotted out long before that old flat six and tranny ever thought of giving up.
    Oh, yeah, it was a real dog.
  4. slapshot
    Joined: Sep 29, 2005
    Posts: 184

    from Belgium

    Hi , I got a '51 dodge coronet with a gyromatic transmission .
    The best thing I can say about it is ... it works . But it is very SLOW at shifting up !!!
    You only use your clutch to select the 3 different gears : reverse , LOW or HIGH gear . Once you've selected a gear you can shift up (after you reached a curtain speed) by releasing your foot from the accelerator , now it will shift up automatically . Shifting down happens when you are driving under a curtain speed or when you use the kick down .They made the LOW gears to be used for pulling heavy weights or going up hill , and HIGH gear for normal use .
    It's a little different but you'll figure it out !
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  5. Retrorod
    Joined: Jan 25, 2006
    Posts: 1,989


    I remember my Mother's 1952 DeSoto had one of those. The thing must have weighed 900 pounds....a big old cast iron piece with the clutch and converter. She always said it was a "Tip-Toe shift automatic". It was really hard to get that little Firedome V-8 to burn rubber with that trans. It leaked oil all over the place as I recall.
  6. cody440
    Joined: Jan 15, 2005
    Posts: 54


    If it ever dies on me, what is the options for replacement, would i have to put another gyromatic back in?
  7. no, you could change it to a regular Dodge Fluid Drive (yuck)
    a Powerflite 2 speed auto (yuck)
    a plymouth three speed stick (less yuck)
    a Plymouth/Dodge three speed with overdrive (now we might be getting somewhere worth going)
    or buy/build an adapter to run a more modern stick or auto trans
  8. bigticket
    Joined: Apr 29, 2005
    Posts: 34

    from Ithaca NE

    I would call Wilcap (do a google search) and he makes a neat adaptor to hook a 350 turbo up to that flat 6 motor you have in the dodge...It really works slick...I know cause I have one on my Desoto powered hot rod....go to to see the whole set up.....bigticket
  9. plym_46
    Joined: Sep 8, 2005
    Posts: 3,726

    from central NY

    Chrylsler applied the term Fluid Drive to a number of different applications. Most common was Dodge's Fluid drive which was a regular 3 speed transmission with a regular clutch and throw out bearing bolted to a 1 to 1 fluid coupler. No torque multiplication, in actuality it was a 1 to .95 deal. It did allow you to select one gear by using the clutch, then by using the brake and gas pedal drive around albeit not very briskly, or you could drive it just like a three speed of the day. Gyromatic was introduced in 49 or 50 and was Dodge's version of the M-6 semi automatic. As stated befor the clutch was used to select a drive range, either low or high, then with a series governors solenoids, igntion interuptors, etc. the tranny would shift up after 12 mph with a release gaspedal, and a sufficient amount of time. Later versions of these had a slight torque multiplication factor. This transmission was very similar to DeSoto's tip toe. Was used through 54/55 when the Powerflite 2 speed fully automatic (precursor to the torqueflite) was introduced.

    For an everything you wanted to know about early MOPAR trannys, go to

    The Imperial Club website also has a detailed article, including repair manual pages.

    Since MOPAR FLUID DRIVE FLUID is no longer available, several folks are succefully using Universal Tractor Hydraulic Fluid for replacement fluid if needed, complete drain and flush are recommended.

    Bullet proof but less than peppy.

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