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DG250M won’t shift out of 2nd (direct drive) and clunks in park or neutral

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  • Transmission / Overdrive: DG250M won’t shift out of 2nd (direct drive) and clunks in park or neutral

    I have a rebuilt DG250M and torque converter in my Speedster that won’t release the direct drive pressure causing the car to stall when slowing down to a stop. I confirmed with a pressure gauge per the shop manual that it does not release the pressure to the clutch pack. The governor and valve in the extension housing seam to be free, installed properly, and operational. I confirmed the correct governor spring is installed per the manual.

    If anyone has ran into this before or has an idea, I would like to hear about it.

    Thanks,
    Matt
    Last edited by Matthew Wendt; 12-25-2019, 05:11 PM.
    Matthew Wendt

  • #2
    I'll be watching this with interest as I have the same problem. The shop manual lists the following possible causes.



    A. Improper governor valve operation: Correction

    1. Governor stuck in direct drive position: Inspect and free up
    2. Hydraulic detent stuck, holding governor in direct drive: Remove and free up
    3. Governor sticking on governor shaft: Free up or install new shaft
    4. Governor valve sleeve out of position in housing: Replace extension housing
    5. Blocked governor valve drain passage: Eliminate obstruction (Drain is at governor valve)

    B. Damaged or sticking direct drive clutch in convertor: Replace convertor.
    Don Wilson, Centralia, WA

    40 Champion 4 door*
    50 Champion 2 door*
    53 Commander K Auto*
    53 Commander K overdrive*
    55 President Speedster
    62 GT 4Speed*
    63 Avanti R1*
    64 Champ 1/2 ton

    * Formerly owned

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    • #3
      I have experienced this problem with a DG transmission. Sorry, I can not think of a solution.
      Don's post no. 2 gives the things for you to check.
      Gary L.
      Wappinger, NY

      SDC member since 1968
      Studebaker enthusiast much longer

      Comment


      • #4
        The problem was two fold, the wrong governor spring was installed. There are two lengths, the correct length is 2-11/16. Also the gasket for the rear pump was incorrect causing the drain passage to be blocked. With both corrected it now functions.
        Matthew Wendt

        Comment


        • #5
          Originally posted by Matthew Wendt View Post
          The problem was two fold, the wrong governor spring was installed. There are two lengths, the correct length is 2-11/16. Also the gasket for the rear pump was incorrect causing the drain passage to be blocked. With both corrected it now functions.
          Congrat's. on the solution.
          Thank you for reporting the solution.
          I hope that you notified the rebuilder of the errors so that they do not happen to someone else.
          Gary L.
          Wappinger, NY

          SDC member since 1968
          Studebaker enthusiast much longer

          Comment


          • #6
            The problems continue. I finally got the tachometer back from a gauge shop that would actually service the unit. To test it on the car yesterday I reved the warm engine to around 3000 rpm in park and an awful clunk comes from the transmission intermitentaly. It seems that it will do it most when coming down from the high RPM back to idle. Fluid is full, checked warm in low gear.

            I drove the car about 2 miles before salting the roads months ago and it seemed good in Drive, but I think it still happened once. At the time I thought it was just a one time thing. This transmission rebuild has been a nightmare. I sourced an entire different one and torque converter and found a shop that will rebuild it in May.

            Shop Manual doesn’t discuss this symptom. Very little is operating in park or neutral, rules out rear pump, governor, rear parking pawl, direct drive clutch, servos, etc... The rebuilder didn’t keep track of what main spool shim was used between this and another transmission, but the clunk feels more than an end play issue. Torque converter was rebuilt. The rebuilder went through the main shaft with a very experienced rebuilder, and it should be good, but who knows at this point.

            Any other ideas?

            Matthew Wendt

            Comment


            • #7
              Matthew, I read somewhere, perhaps on this forum, that it is not recommended that you rev the engine too high with a DG transmission in park or neutral. It can be damaged. Poke around, I think you will find something about that. As you likely learned, these transmission are complicated and most transmission shops aren't familiar with them. They should only be rebuilt by someone who has experience with them.
              Ed Sallia
              Dundee, OR

              Sol Lucet Omnibus

              Comment


              • #8
                As stated, you should NEVER rev engines using this transmission to a high RPM when in park or neutral and standing still. The lock up feature in the torque convertor will try to engage. If it does, it will probably stay locked up. I have personally experienced this.
                Gary L.
                Wappinger, NY

                SDC member since 1968
                Studebaker enthusiast much longer

                Comment


                • #9
                  Studegary, I appreciate the insight. Could you please clarify how this can happen in park or neutral? Per the shop manual page 31 and 32 of the Automatic section, the diagram shows no way pressure could get to the direct drive clutch to lock it or even the centrifugal govenor where the speed of the car would cause the direct clutch to engage. I don’t understand how engine speed could cause this.

                  It just doesn’t seem right that by 55 you couldn’t moderately rev an engine in park or neutral safely. I would appreciate any others as well to confirm. My next step was going to be to measure pressures of the servos, make sure there not engaging, front pump, and the direct drive clutch, make sure it is not engaging when this happens.

                  Is it possible a free wheeling unit is hanging up?

                  Thanks,
                  Matt
                  Matthew Wendt

                  Comment


                  • #10

                    Moderate Reving yes, 3000 rpm no.
                    I am not sure, but I think that it is centrifugal force that causes the convertor to lock up. I am not sure what is happening within the DG transmission, I just know that it happens.
                    Gary L.
                    Wappinger, NY

                    SDC member since 1968
                    Studebaker enthusiast much longer

                    Comment


                    • #11
                      Matt, Isn't there a one-way, Sprag Clutch in there that sometimes tries to lock the direct drive Converter when revved up or even fast idling in Park or Neutral?

                      I have heard these '55's (owned one once), go clang, clank like trying to lock.
                      That has to mean that Unit is failing.
                      The 250M does have the Low Gear Start which I thought, but do not know if that is the reason for the Sprag.
                      StudeRich
                      Second Generation Stude Driver,
                      Proud '54 Starliner Owner
                      SDC Member Since 1967

                      Comment


                      • #12
                        Hello all , I have the same DG Auto in my 1953 V8 , the loud clunk noise when the engine is revved up is normal, the shop manual states that you should not rev the engine in park or neutral, sometimes on the road the clunk can also be heard when the converter locks up into top gear , again normal for this type of auto , i have been driving mine for 20 years with these noises and had no problems, merry xmas.
                        R.A.Jennings

                        Comment


                        • #13
                          I don't know if this will help but I have a flightomatic which had a newly rebuilt torque converter which failed. The car would drive normally until you tried to leave it in gear when stopping and it would kill the engine unless you had one foot on the brake and the other on the accelerator. It turned out to be a broken sprag in the torque converter. Of course being newly rebuilt only extended the time it took to identify the problem.

                          Comment


                          • #14
                            Originally posted by 5brown1 View Post
                            I don't know if this will help but I have a flightomatic which had a newly rebuilt torque converter which failed. The car would drive normally until you tried to leave it in gear when stopping and it would kill the engine unless you had one foot on the brake and the other on the accelerator. It turned out to be a broken sprag in the torque converter. Of course being newly rebuilt only extended the time it took to identify the problem.
                            Apples and oranges. The Flightomatic does not have a lock up torque convertor like the DG transmissions have.
                            Gary L.
                            Wappinger, NY

                            SDC member since 1968
                            Studebaker enthusiast much longer

                            Comment


                            • #15
                              Waded through cob webs,owned a 55 State sedan in early 70's,had same problem. clang clunk is caused by centrif. force. info came from really old trans shop in Killeen Texas. never had any trans problems in 20 odd years of driving. Don't rev it up hard! Luck Doofus

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