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Engaging Overdrive Causes Discharge

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  • Electrical: Engaging Overdrive Causes Discharge

    I have a '64 SR wagon and recently have had a discharge while driving. After checking the usual alt. and reg. I noticed on my drive this AM that while idling and driving slowly there is a positive charge on the gauge. When the gov. tells it to engage I see a discharge and the OD will NOT engage. I checked the fuse and it is good! This is a weird coincidence. Anyone have any thoughts as to the problem? I don't hear the usual click at all. How does one check a 3 wire solenoid out of the car? A governor as well.
    Thanks!
    Rob in PA.

  • #2
    http://www.studebaker-info.org/tech/.../bwservice.pdf

    Try it with taking the torque of the drive train by taken your foot of the gas when you expect it to shift into overdrive.
    If it shifts "ok" , then the temporary contact in the solenoid that shorts the ignition
    for a split second while it is traveling its stroke is not doing its job.
    On the older overdrives before the three wire solenoid it was done by the overdrive relay.
    Either the contact in the three wire solenoid or the contact transfer time in the overdrive relay in systems so equipped , will short the ignition coil for a split second to take the torque of the transmission to give the plunger a chance to move.
    The solenoid is not strong enough to pull the plunger in when there is torque on the gears.
    The solenoid has two coils, both are used to pull in and when the solenoid pulls in all the way it disconnects the second coil and the still energized coil is the holding coil.
    If the contacts in the solenoid are bad the holding coil is not strong enough to pull the plunger.
    The fact that your amp meter goes to discharge is that the two coils are using a lot of current trying to pull the solenoid in but if it does not pull in , the second coil is not disconnected by the contacts activated by the solenoid when it is fully engaged and the high current will eventually burn the solenoid up or destroy the contacts.
    A much better description is found in the link on the top of this post

    Robert Kapteyn
    Last edited by rkapteyn; 07-17-2016, 12:29 PM.

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    • #3
      Remember that '64 and later governors are two terminal and it is the hot lead that goes through the governor. '63 and prior systems had the ground lead triggered by the governor.
      I've had to dis-assemble and clean the contacts in '64 type governors before. That always cured my problems with engaging overdrive.

      Comment


      • #4
        Originally posted by rkapteyn View Post
        http://www.studebaker-info.org/tech/.../bwservice.pdf

        Try it with taking the torque of the drive train by taken your foot of the gas when you expect it to shift into overdrive.
        If it shifts "ok" , then the temporary contact in the solenoid that shorts the ignition
        for a split second while it is traveling its stroke is not doing its job.
        On the older overdrives before the three wire solenoid it was done by the overdrive relay.
        Either the contact in the three wire solenoid or the contact transfer time in the overdrive relay in systems so equipped , will short the ignition coil for a split second to take the torque of the transmission to give the plunger a chance to move.
        The solenoid is not strong enough to pull the plunger in when there is torque on the gears.
        The solenoid has two coils, both are used to pull in and when the solenoid pulls in all the way it disconnects the second coil and the still energized coil is the holding coil.
        If the contacts in the solenoid are bad the holding coil is not strong enough to pull the plunger.
        The fact that your amp meter goes to discharge is that the two coils are using a lot of current trying to pull the solenoid in but if it does not pull in , the second coil is not disconnected by the contacts activated by the solenoid when it is fully engaged and the high current will eventually burn the solenoid up or destroy the contacts.
        A much better description is found in the link on the top of this post

        Robert Kapteyn
        Excellent information...Thanks!

        Comment


        • #5
          I don't think the grounding contact is at fault. That contact is grounded all the time the solenoid is engaged, and simply makes ground available to the kickdown switch when OD is engaged. OP's car is not engaging overdrive, so the grounding switch is not involved. My guess is the solenoid is not able to make its full stroke, and the high-current pull-in coil is staying powered up for more than the usual fraction of a second it normally needs.

          Job #1! Push the lockout handle all the way in, get under car (suitably supported and engine off) and verify that the lockout lever is fully back against its stop. If it is not, and it takes only a small fraction of an inch of slack to mess things up, adjust the cable so the lever is all the way back against the stop when the OD lockout T-handle is about 1/8 to 1/4" away from the dash bezel. That enables the driver to feel when the lever hits the stop. If you set the handle gap at zero, it could work fine for years, but you can't tell if the bump you feel when it is pushed in is the lever hitting the stop, or the T-handle hitting the bezel. Setting a slight gap eliminates that ambiguity, and allows for cable stretch, settling, and so on.

          Get that little job done, and report back with the results.
          Gord Richmond, within Weasel range of the Alberta Badlands

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          • #6
            Thanks for all the info. It looks like I have my homework assignments to do. I will report back as this evening I went to pull the car in the garage and noticed a small puddle of gear oil on the driveway.
            Rob in PA.

            Comment


            • #7
              I'll echo the discussion on "cable to stop" fix. Even the slightest lack of stop will cause problems.

              Comment


              • #8
                THE FIX!!!!!!!!!!!!!!!!! Drum roll please..................... It was the solenoid! I
                figured since the discharge was occurring when the gov. kicked in the solenoid I'd swap out the solenoid. It also seemed there was a slight oil leak at the solenoid so maybe that O ring was weak from the load on the solenoid. I had another one at hand so dropped the wagon off the stands, put in the fuse at the kickdown and off we went. The first indication it might work was the fact that it didn't discharge at 29 ? mph. It went into OD real sweet just as it used to do. After warm up and some speed I kicked it down too! Works like a charm again. Thanks for the input from everyone. This may save someone else some time and effort. This Forum is fantastic!
                A big THANKS.
                Rob in PA.

                Comment


                • #9
                  Glad you fixed the problem.
                  Don't throw the old solenoid away. There is a chance that it can be fixed and they are becoming harder to find.
                  RadioRoy, specializing in AM/FM conversions with auxiliary inputs for iPod/satellite/CD player. In the old car radio business since 1985.

                  17A-S2 - 50 Commander convertible
                  10G-C1 - 51 Champion starlight coupe
                  10G-Q4 - 51 Champion business coupe
                  4H-K5 - 53 Commander starliner hardtop
                  5H-D5 - 54 Commander Conestoga wagon
                  56B-D4 - 56 Commander station wagon
                  60V-L6 - 60 Lark convertible

                  Comment


                  • #10
                    Roy-I save everything. I have cores for the OD's, generators,alternators, water pumps, master cylinders, steering boxes etc. I even found a number of roll up antennas! Ideally if someone were to rebuild some of this stuff they could give me some and sell the rest.
                    Thanks!
                    Rob in PA.

                    Comment


                    • #11
                      Originally posted by stude1964 View Post
                      Roy-I save everything. I have cores for the OD's, generators,alternators, water pumps, master cylinders, steering boxes etc. I even found a number of roll up antennas! Ideally if someone were to rebuild some of this stuff they could give me some and sell the rest.
                      Thanks!
                      Rob in PA.
                      Rob. Sounds like we are on the same page. I save everything, too. You never know when it will become useful.
                      RadioRoy, specializing in AM/FM conversions with auxiliary inputs for iPod/satellite/CD player. In the old car radio business since 1985.

                      17A-S2 - 50 Commander convertible
                      10G-C1 - 51 Champion starlight coupe
                      10G-Q4 - 51 Champion business coupe
                      4H-K5 - 53 Commander starliner hardtop
                      5H-D5 - 54 Commander Conestoga wagon
                      56B-D4 - 56 Commander station wagon
                      60V-L6 - 60 Lark convertible

                      Comment


                      • #12
                        Originally posted by stude1964 View Post
                        Roy-I save everything.
                        Rob in PA.
                        Rob is a caretaker of history. Most everything, even if it is not perfect, has some purpose at some point and should be given the opportunity. Always thinking about the unthinkable (possible vehicle damage), Rob had squirreled away most everything he would need to repair any of his vehicles. At one point as we were talking, we counted 16 sets of '64/'65 wheel covers...and those were the ones we could see...
                        Last edited by 62champ; 07-19-2016, 02:02 PM.

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