Dynaflow - Kickdown

Discussion in 'The "Juice Box"' started by German57Special, Apr 15, 2009.

  1. German57Special

    German57Special Rope Seal Terminator

    Is a Dynaflow supposed to have a kickdown like most automatic transmissions?

    I asked the guy that owns this Buick I am working on right now if his kickdown worked before. He first asked me what a kickdown was and after I explained it to him he said it didnt shift back when he hit the gas.

    I seen a linkage when we were taking it apart but am not sure what it is for.
    I am also thinking that a linkage is missing on the carter carb he has.

    Can somebody look at the pictures and tell me what the linkages are for and if there is something missing?

    In the first picture I know that the one on the bottom is the gear selector but I am not sure what the one is at the top.


    Attached Files:

  2. 71skylark3504v

    71skylark3504v Goin' Fast In Luxury!

    Single barrel? :blast:
  3. rmstg2

    rmstg2 Gold Level Contributor

    To my knowledge the only kickdown in a Dynaflow was the VP converter going to high stall when it was floored. They don't shift back to low range.

    Bob H.
  4. buick64203

    buick64203 Just plum crazy Staff Member

    Dynaflows dont shift. They only have one forward gear. There wouldnt be any gear to shift down to.
  5. telriv

    telriv Well-Known Member

    There's a rod that connects the high accumulator to the throttle linkage. You can see it in the 1st. picture. Not the long bar leading to the rear of the trans. That is for the actual gearshift. All the accumulator does is change the pitch of the vanes in the torque converter from low stall to high stall. Almost like a high stall race converter.
  6. austingta

    austingta Well-Known Member

    They do have a low range that can be used up to 45 MPH or so. When it is engaged at idle, you feel a distinct shift.

    When in Drive, the trans does start in 'second' gear and accelerate smoothly to top speed. It was an awesome trans in my 63 Wildcat. I loved it!

  7. German57Special

    German57Special Rope Seal Terminator

    Thanks for the answers. Now I understand how the dynaflow works.

    Where does it hook to the throttle linkage?
    At the back of the engine where it ends now or is there a rod missing to the carb?
    We were thinking about changing the intake and carb but the owner wants to keep it original.
  8. d2_willys

    d2_willys Well-Known Member

    Actually the dynaflow is a 2 speed transmission, but not like most 2 speed autos. The torque converter has two turbines, one drives a planetary, the other drives the tailshaft. So when starting out, the first turbine gives you a first gear of a kind, and after the first turbine gains speed, the 2nd turbine takes over. The shifting is smooth as it is all done by the converter. The converter has the variable pitch stator blades, which do change the torque converter stall speed (or torque multiplication), but the only downshifting available is to manually shift to the lo range for greater acceleration.
  9. telriv

    telriv Well-Known Member

    There is NO shifting at all when the DynaFlow is in drive range. It is ALL a fluid connection ONLY!!!! That's why they were SO SMOOTH!!! Many luxury cars of today try to emulate the DynaFlow. Some by starting in 2nd. gear. Others by not doing any downshifting when slowing down, some as slow as 5MPH, & staying in high gear & letting the torque converter slip to provide the power to move the vehicle. Reason many have trans. that go bad, extreme heat. As well as having a switch-pitch feature in drive range, they also have a switch-pitch in low & reverse as well. Reverse is FUN when the go pedal is put to the floor. Actually a DynaFlow has more torque multiplication in low than a TH400. Have actually run the whole 1/4 in low gear at 6K RPM's.
  10. d2_willys

    d2_willys Well-Known Member

    Actually no perceivable shifting of gears, but the twin turbine converter does give you a reduction (through planetary that is driven from the first turbine in converter) at dead start and gets phased out smoothly as the second turbine kicks in. No there are no shifts like a step type automatic.

    I remember reading that Buick re-routed the switch pitch control when in LO to disable it in that range. Think this was a one year thing, around 55 or 56.

    Also noting the torque multiplication is greater than TH400, well that is done through the planetary in the torque converter, which is active on standing still acceleration. This, along with switch pitch stator, gives you all the torque multiplication noted.
  11. German57Special

    German57Special Rope Seal Terminator

    Thanks again for the answers. :TU:

    I went here and read up on the Dynaflow. I guess you learn something new every day. :rolleyes: I think its cool as heck the way that thing works.

    Oh and thanks for making my TH400 sound bad that I have in my truck. :laugh:

    Now I know alot more about the Dynaflow than I did yesterday.
    I still dont know where the linkage is supposed to be hooked to the throttle.
    On the back of the engine or to the carb?
  12. telriv

    telriv Well-Known Member

    I'm pretty sure it's attached at the back of the engine on the throttle linkage. I don't believe it goes to the carb. That didn't start till '61.
  13. German57Special

    German57Special Rope Seal Terminator

    I got it up to the Bracket bolted to the Head but just cant figure out where it goes from there. I have an original chassis manual on a dvd but just cant find anything about it in there. I could take the whole transmission apart and put it back together using that manual but just cant find anything about the linkage.

    @ Telriv - Where are you from in ct. My brother lives in Pawcatuck.
  14. telriv

    telriv Well-Known Member

  15. d2_willys

    d2_willys Well-Known Member

    I will check my motors manual, scan pics if I can find some. I may have that same linkage in my 58 Buick manual that I can scan. Will post if I can find anything.
  16. German57Special

    German57Special Rope Seal Terminator

    If everything goes like we planned, we will be starting her up on Saturday.

    It would be great to get any information or pictures about the linkage.

    I think it will start and drive without it because it wasnt hooked up before.
  17. German57Special

    German57Special Rope Seal Terminator

    We finally got her running. A couple of little things and she will be back on the road.
    We were at a meet here in Nuernberg last friday and there was a 57 Super there with the same engine and Tranny.
    She let me look in the engine compartment and yes, there is a rod missing on the special. Now all we have to do is find out where we can get one of these.

    I´ll post a picture showing the rod.

    Attached Files:

    Last edited: May 11, 2009
  18. telriv

    telriv Well-Known Member

    I'll look at the '57's I have & see if the rod is still there.
  19. RealSteelSharon

    RealSteelSharon New Member

    Hi guys. I am a newbie to this forum, and my husband and I are currently looking at purchasing a 1957 Buick special 4door.

    The current owner has been doing some mechanical work before we take possession of the car, and had the gearbox rebuilt. When he went to re-install the gearbox in the car the rebuilder asked for the linkage. The owner now can't find it, and after much research we found this forum, and this thread which was extremely helpful in showing us what he was supposed to be searching for....

    Unfortunately, he still can't find it, and we were wondering if anyone could help in telling me where we could buy one? Or does anyone have a parts car with the linkage for sale?

    Many thanks.
    Real Steel Sharon
  20. German57Special

    German57Special Rope Seal Terminator

    We did get our Kickdown linkage on but it wouldn´t work right anyways.
    It doesn´t keep the owner from cruisin though.
    The only place that pops in my mind right now would be Bob´s Automobilia.
    Go there and download his Catalog and look through it. Maybe he has one.

    I looked through the catalog real quick and can´t find one.
    Maybe just give them a call, if they don´t have one maybe they can tell you where to get one.

    Last edited: Dec 6, 2009

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