- 1964-1967 SP400 Parts Images
- How to wire the Switch Pitch on a Buick Transmission
    - 400 auto codes
- BOP Bellhousings and Automatic Identification
Results 1 to 8 of 8

Thread: Dynaflow Transmission won't shift

  1. #1
    Join Date
    Aug 2012
    Location
    Rochester
    Posts
    27
    Rep Power
    0

    Dynaflow Transmission won't shift

    Hey Guys,

    This weekend I pulled my motor and transmission out of my 1956 Special 4 door (automatic). When I bought the car a couple of weeks ago I couldn't get the shift on the tree to move out from neutral. So after pulling the motor and separating the transmission from the motor the shift lever on the transmission is still locked. From the start I thought the transmission was an issue with the car....My Question is?....was there a common issue with this Dynaflow auto transmission back in the day...and can it be repaired without sending it out to a transmission shop. Also, I couldn't get the torque converter to come out from the trans after disconnecting it from the fly wheel...any suggestions on both of my issues here would be greatly appreciated

    Sincerely

    Perry

  2. #2
    Join Date
    Dec 2011
    Location
    SanFran CA
    Posts
    1,155
    Rep Power
    0
    Do you know how long the car was sitting before you bought it?

    I would say it was fairly unusual to have the shift lever lock up unless the parkng pawl got overstressed. Back in the day, it was much more common for the transmission to leak, slip, make strange noises, or refuse to engage any gear at all. I suppose it is possible for the manual control valve to seize if water got inside the tranmission and it sat long enough. This could certainly lock the shift lever, but then you would also have a bunch of other problems as well.

    The Dynaflow converter is unlike any other converter on any other transmission you are likely to have worked on. To get it off of the transmission you must disassemble the converter from the outside in.

    There aren't many shops left that are willing to work on a Dynaflow these days. If you know of one in your area, consider yourself lucky. If you are brave enough to want to dig into the transmission by yourself, Team Buick has a 1957 service manual online. The Dynaflow section is here.
    http://www.teambuick.com/reference/l...hassis/5-a.php
    The major difference between the 57 transmission and yours is the output shaft and tail housing. The converter is enough like yours that you should be able to get it apart using the 57 instructions.

    Ray
    Last edited by raycow; 08-26-2012 at 09:30 AM.

  3. #3

    Dyna flo.....

    On cars of that vintage, a lot of times the ''no reverse'' condition is a result of a broken reverse band.... or the adjustment being so loose on the reverse band that the trans wont back up....
    Pick up a Motors auto repair manual of the appropriate years ,,, it will have all the info you need to correct the problem.....

  4. #4
    Join Date
    Aug 2012
    Location
    Rochester
    Posts
    27
    Rep Power
    0

    Trans mission lever wont shift

    Quote Originally Posted by raycow View Post
    Do you know how long the car was sitting before you bought it?

    I would say it was fairly unusual to have the shift lever lock up unless the parkng pawl got overstressed. Back in the day, it was much more common for the transmission to leak, slip, make strange noises, or refuse to engage any gear at all. I suppose it is possible for the manual control valve to seize if water got inside the tranmission and it sat long enough. This could certainly lock the shift lever, but then you would also have a bunch of other problems as well.

    The Dynaflow converter is unlike any other converter on any other transmission you are likely to have worked on. To get it off of the transmission you must disassemble the converter from the outside in.

    There aren't many shops left that are willing to work on a Dynaflow these days. If you know of one in your area, consider yourself lucky. If you are brave enough to want to dig into the transmission by yourself, Team Buick has a 1957 service manual online. The Dynaflow section is here.
    http://www.teambuick.com/reference/l...hassis/5-a.php
    The major difference between the 57 transmission and yours is the output shaft and tail housing. The converter is enough like yours that you should be able to get it apart using the 57 instructions.

    Ray
    Thanks guys for the info....the car has been sitting since 1970. I do have a shop on the east side that still works on dynaflow transmissions....I would really like to use this transmission if its at all possible. On the other hand, lets say I have to omit or op-out of this original transmission... What would you think Ray to be a suitable replacement? Well, thanks again for all your insight....I'm working on rebuilding the motor over the next month and then onto the transmission....God Bless

    Perry

  5. #5
    Join Date
    Jan 2010
    Posts
    115
    Rep Power
    0
    Absolutely no need to go into another trans frankenstein setup combo. Get a rebuild kit from this David. http://www.autotran.us/. Rebuilders use him. Get the manual on the dynaflow. The Buick OEM shop manual has an excellent section on servicing the Dyanaflow. If you should elect to get outside help there are places that rebuild this transmission. Just make sure they use your kit and not some cheap ebay stuff. Investigate, read and learn. It can be easily done. You will have a nice dependable transmission while keeping it original and maintain it's value.
    Thanks in Advance!

    David

    Born Buick - " I like things just the way they were and drive-em just the way they are "

  6. #6
    Join Date
    Dec 2011
    Location
    SanFran CA
    Posts
    1,155
    Rep Power
    0
    Sitting since 1970 - that would have done it for sure. I don't know of any automatic that could survive 40+ years of dead storage unless it was kept indoors in a climate-controlled room.

    David is absolutely right. If you wanted to swap any transmission other than a Dynaflow or the stock 3 speed manual, the car would have to be modified extensively. This would definitely involve more work and money than rebuilding your present transmission. In the event it can't be rebuilt (because of internal corrosion), rebuildable cores are still out there.

    Before you commit to a course of action, I recommend that you first read through the service manual from beginning to end. Then decide whether you want to bring the transmission to a competent shop (which you are fortunate to have) or else take on the job yourself.

    Please let us know which route you choose, and keep us posted about any developments along the way.

    Ray

  7. #7

    Ol Dyna......is a good ol gal.....

    I am with David and Ray on this one.... it is cheaper and easier to just fix the Dyna than to tackle the closed driveshaft monster..... and convert it to another trans and open driveshaft....and,,,, I might add , a dyna in good shape is very, very tough....but I would not be surprised if instead of this being a rebuild possibility, You or your mech found a simple, easy, mechanical linkage problem instead.... and,,, like pointed out earlier, that many years will cause seals to harden and shrink.... so the absolute best solution would be to just go all the way through the trans with a rebuild.....

  8. #8
    Join Date
    Aug 2012
    Location
    Rochester
    Posts
    27
    Rep Power
    0

    Quality Answers

    Quote Originally Posted by DocModisett View Post
    I am with David and Ray on this one.... it is cheaper and easier to just fix the Dyna than to tackle the closed driveshaft monster..... and convert it to another trans and open driveshaft....and,,,, I might add , a dyna in good shape is very, very tough....but I would not be surprised if instead of this being a rebuild possibility, You or your mech found a simple, easy, mechanical linkage problem instead.... and,,, like pointed out earlier, that many years will cause seals to harden and shrink.... so the absolute best solution would be to just go all the way through the trans with a rebuild.....
    Thank you David & Ray,I'm kind of a hands on guy, like to know its done correctly as well as doing and learning myself along the way. I'm going to purchase the kit you suggesgted and rebuild it myself...if I get stuck...I'll seek the answer to understand whats happening in that thing....in two years I want to say I built this puppy from head to toe...nothing wrong in that..My grandfather use to always say preparation is the key to everything....thanks a million you guys are top quality..God blessPerryHey guys I called David Edwards and ordered the dynaflow kit.....thanks again
    Last edited by Perry; 08-27-2012 at 09:28 AM. Reason: Bought Trans Kit

Similar Threads

  1. 1950 Dynaflow Shift Lever
    By Mike1947 in forum Transmissions and Drivelines...
    Replies: 4
    Last Post: 06-25-2012, 07:09 AM
  2. 62 Skylark Transmission won't shift right
    By wgh234 in forum Transmissions and Drivelines...
    Replies: 0
    Last Post: 10-07-2007, 04:17 AM
  3. Dynaflow shift pattern?
    By Chopper Johnny in forum Straight Eights!
    Replies: 12
    Last Post: 09-28-2006, 05:59 PM
  4. 1998 automatic transmission shift solenoid
    By s1sadm1n in forum Transmissions and Drivelines...
    Replies: 2
    Last Post: 07-17-2004, 07:13 PM
  5. dynaflow transmission
    By Tonyrose in forum Transmissions and Drivelines...
    Replies: 1
    Last Post: 04-04-2002, 02:40 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
TeamBuick.com Privacy Policy