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O.T. torqueflight transmission ?

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  • O.T. torqueflight transmission ?

    early 70's era, and think it's actually considered a loadflight but from what I hear their similar

    anyhoo, drive is drive - second is second and first is first, but - will not free rev in park - seems to actually be still in a gear and working against the park sprags, also;

    neutral is drive and will move vehicle foreward but seems to be engaged when in reverse also - so I think it has reverse in a sense but vehicular won't move yet engine is under load and raises on its motor mounts when throttle is applied, so seems like its engaging drive and reverse at the same time when in reverse and vehicle grid locks and even though under load goes nowhere,

    for the record - the shift cable is adjusted properly...

    so who's the torqueflight guru that can enlighten me, thanks ahead of time, im hoping it's just access through the pan so I can help a friend out and if not I do not think I will be getting involved...

    Also; I have had the pan off and changed filter and half it's fluid, and got a good look at the shift pin actuator and all seems normal throughout the range - not anything funny in pan although little bit of sludge build up in a few areas,

    all valve body springs and such seemed to be in order and nothing funny looking - all valve body bolts tight,

    im all ears this is a dinosaur to me and im hoping its a common problem that's not too involved... thanks again.
    Last edited by A.K. Boomer; 07-27-2017, 03:57 PM.

  • #2
    One problem I had on an older vehicle was that the indicator mechanism would indicate incorrectly like yours seems to be doing. What I was told was that the tension spring in the indicator mechanism weakens over the years and will not bring the indicator back into the correct location to show D, N, R etc. The solution was to replace the indicator on the column.
    Glenn Bird

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    • #3
      mine is not indicating incorrectly - the cable is adjusted properly and so is the indicator, first thing I checked.

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      • #4
        Those were tricky beasts but if I recall correctly most problems could be traced back to the turbo encabulator.

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        • #5
          You know how they work...... in general....

          Are the clutches doing their thig in the different settings? Yeah, you can't look at it work when buttoned up, but maybe you can see if the actuators can move correctly

          Kinda seems like something must be stuck......
          CNC machines only go through the motions

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          • #6
            WOW!, lots of issues. I gotta ask, what all led up to this? Obviously this didn't happen overnight or by itself. Do you know how all this happened or how he got to your shop or at least to this stage?

            I've had lots of TF's apart and they are an easy transmission to rebuild and or modify. Torqueflite, Loadflite, Powerflite are all very similar, main difference is application, car or truck. Some internal components reflect this in clutches, settings, line pressures, etc. but functionally they all operate on the same principle.

            Sounds very much to me like either the linkage is way out of adjustment, could be at the trans control itself, not the linkage between column and trans, sometimes these are abused to the point that the adapter clamp has been twisted out of phase to where it should be. Have you tried to shift the trans via the control linkage only while on the hoist to verify actual positions and their function? easy to disconnect column linkage from the trans.
            Have you checked the band settings, this is easy to check and is VERY important. Kick-down band adjustment is next to the shift control input on left front of case, low-reverse band is internal and is easily accessed when the pan is off. Don't forget to set the throttle valve/kick-down adjustment at the carb when all is done.

            If bands are in spec and shift control detents are identifiable and precise look into over-running clutch issues and valve body problems like leakage or internal malfunction.

            Also I should mention that if you want to do a complete fluid change the torque convert should have a drain plug, dont forget to flush the cooler lines and the cooler if your friend wants you to be thorough.

            Not quite as nice as what I have before me, however the links below should give you some valuable insight into what makes the 727/904 automatics tick.

            Good explanation of power flow thru the 727 trans. in the video.

            973 Master Technician Service Conference
            Transmission Torqeflite Testing Diagnosis
            Chrysler Plymouth Dodge Imperial


            6.4MB Service Manual





            Home, down in the valley behind the Red Angus
            Bad Decisions Make Good Stories​

            Location: British Columbia

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            • #7
              AK, have a look at this version of the 727 manual, it better illustrates the hydraulic circuit flow while in various control positions and what circuit is activated when in each of those positions..

              http://www.jholst.net/70-service-man...ansmission.pdf

              Gotta go, all at once I have a boatload of folks here in the shop wanting to socialize, works done, happy hour starts early this week. LOL
              Home, down in the valley behind the Red Angus
              Bad Decisions Make Good Stories​

              Location: British Columbia

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              • #8
                Thanks for the info Willy I will look in depth at the last link as checked out the others and pretty inconclusive so far

                I stated something wrong - said the engine climbs on its mounts and it does not do that it's all internal locking up but can tell the engine is laboring even in park when you try to rev it and it wont, I think for it to climb on it's mounts that would mean it's getting the driveshaft involved and it's obvious its not -
                I believe its stuck in both forward and reverse when it's put in reverse - in neutral its stuck in drive but you can seem to free it up if you try to drive it that way sometimes does go to neutral and you can free rev,
                im sure once I got it in that mode that I tried reverse to see what would happen and back to grid lock,

                I think in park it's stuck in drive because I feel the vehicle move enough to get the park sprags involved then its gridlock,

                kinda have to agree with JT it's like somethings stuck maybe a valve actuator that controls first and reverse as from what im gathering they are one and the same.. ?


                history, it's in a motorhome that a friend bought off of a couple and they had used it to live in for something like 8 years, alls they did was buy it and drive it to their property where they were building a house so they cannot remember that far back if it had reverse or not as it was not important to them because it was just park it and live there so they claim they maybe never would have even used reverse, kinda hard to believe unless you met the two - great couple and woman deserves a metal for living in that thing way up in the mountains in sub zero temps for almost a decade...

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                • #9
                  So the tranny was not used for 8 Years? almost sure that some of the valves are stuck. just take the sump of, and see if it all moves free.
                  did you try it wit the cable unhooked ?

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                  • #10
                    Also did you do any pressure testing? After sitting for 8 years all of the internal seals are most likely fubar.
                    Torque flight transmission (semi-automatic) was the poor baby brother of the powerflight and dynaflow real automatic transmissions. It should have PRNDGG, where the two Grade positions are used for extra engine braking, NOT lower gear as in power flight/dynaflow and hydramatic transmissions
                    Last edited by bob_s; 07-27-2017, 07:39 PM.

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                    • #11
                      Originally posted by bob_s View Post
                      Also did you do any pressure testing?
                      no but from everything im reading it seems to be the next step, then if pressure checks out look at mechanical actuation factors - as in seals and band linkage and stuck valve bodies and such


                      I just do not have a real schematic of this thing in my head - it's foreign to me even though it's from my own country...

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                      • #12
                        It sounds like an internal leak, quite possibly from a failed O-ring. Dropping the pan and doing a complete R&R of all seals, O-rings, gaskets, etc and a complete fluid flush might fix the problem. It could be from a mechanical problem with the shift mechanism inside the tranny causing it to want to shift into two gears simultaneously but a visual inspection of the internal shift mechanism when the pan is off will determine if it is or isn't. I have seen one auto tranny where an internal shaft in the valve body actually broke in half at one of the large oil passage grooves so only one end was moving where it should have and the other end wasn't.
                        Location: Saskatoon, Saskatchewan, Canada

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                        • #13
                          Originally posted by Arcane View Post
                          It could be from a mechanical problem with the shift mechanism inside the tranny causing it to want to shift into two gears simultaneously but a visual inspection of the internal shift mechanism when the pan is off will determine if it is or isn't.
                          yeah did that inspection today when replacing filter and gasket along with a visual of the shift mechanism plunger valve and the detent rail and all looked very good
                          I have seen one auto tranny where an internal shaft in the valve body actually broke in half at one of the large oil passage grooves so only one end was moving where it should have and the other end wasn't.
                          That would definitely have me fooled - no X-ray vision here but hand wiggling the plunger valve seems like it still had some internal length even when in the all the way out position...

                          I do not know these units but am learning fast keep em coming guys.

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                          • #14
                            Wow Willy's last links got everything - very detailed

                            I will try to pick this thing apart and let you guys know what I find out,

                            I got michigan certified and was top of my class at the age of 17 but failed one subject - automatic transmissions lol

                            coming back to haunt me - iv learned some tricks of the trade with the stuff I work on but these things are different for sure - still - same operating principle just have to learn the layout... have to look at it this way - computer intervention is not much of a factor so get to eliminate that ghost...

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                            • #15
                              mr boomer, those are easy trannys to build for a mechanic. simple clutch spring compressor is the only special tool youll need. hard part is getting it out of that motorhome. could have a bad forward clutch, or stuck valve. planetary can seize up too but not common.
                              san jose, ca. usa

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