How to test Overdrive Solenoid on '41 120

General topics, not covered elsewhere, of all things Packard.
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introinc
Posts: 13
Joined: Sat Aug 03, 2019 11:07 am

How to test Overdrive Solenoid on '41 120

Post by introinc » Wed Dec 09, 2020 2:56 pm

Does anyone know how the solenoid for the overdrive on a 1941 Packard 120 is rebuilt and tested to ensure proper function? My current solenoid sends signal to the dash indicating it is aligned with the governor and ready to shift at about 30mph and then the light goes out below that speed. However it is not forcing the solenoid piston to extend out fully, only about 1/4in and therefore not engaging the overdrive gears.
I acquired a "rebuilt" solenoid from Max Merritt that was "tested" but it did not even send the signal to the dash light or extend the solenoid piston. Hence my request for any help the club members may be able to supply. Thanks, Craig

Howard56
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Joined: Mon Dec 24, 2012 11:35 am

Re: How to test Overdrive Solenoid on '41 120

Post by Howard56 » Wed Dec 09, 2020 3:32 pm

Your OD should be the R9 and that solenoid would have 4 terminals. Terminal 3 is the holding coil and 4 is the pull in coil. 6 is the ign cutout contacts and 7 is for the indicator light. If by chance it is the wrong solenoid, R11 solenoids have a slightly shorter plunger and only have 2 terminals. Those will not work with the R9 OD. Also check when the solenoid is mounted the spacer is oriented with the small hole to the rear. The spacer is not symmetrical and if installed incorrectly can bind the solenoid. Also make sure the ball at the end of the plunger is inserted in the slot in the pawl and not just pushing against the end of the pawl. Sometimes the solenoid needs to be energized and plunger extended to have enough length to work the ball into the slot.

To test the solenoid you will need to use a heavy gauge wire -- 14 ga should be large enough -- and connect that wire to BOTH terminals 3 and 4. Ground wire would be to the case. When the battery is connected, 4 getting power will allow the pull in coil to extend the plunger and with 3 also having power it will hold the plunger extended when a set of internal contacts open the connection and turn off the pull in coil just before maximum extension is reached. As I recall the extension is right at 1". Either terminal connected by itself and the solenoid will not operate properly. The hold in coil (3) is not strong enough to bring in the plunger so it would appear nothing is happening and with the pull in coil only (4) energized, without the hold in coil connected the plunger will extend, internal contacts will open and the plunger will release only to be pulled in again. A very loud and rapid in and out or "machine gunning" of the plunger is the result.

When the plunger is nearly extended a contact at terminal 7 opens to cut the internal ground connection to the indicator light so it will turn off and at approximately the same time that 7 opens, 6 closes to provide a ground to the ign cutout parts of the circuit so that will be ready when kickdown is desired.
Attachments
R9 solenoid terminals.jpg

introinc
Posts: 13
Joined: Sat Aug 03, 2019 11:07 am

Re: How to test Overdrive Solenoid on '41 120

Post by introinc » Thu Dec 10, 2020 4:52 am

Thanks so much Howard this is very helpful.

introinc
Posts: 13
Joined: Sat Aug 03, 2019 11:07 am

Re: How to test Overdrive Solenoid on '41 120

Post by introinc » Thu Dec 10, 2020 8:21 am

Howard do you know of a good rebuild shop for the R9 solenoid? Thanks, Craig

Howard56
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Joined: Mon Dec 24, 2012 11:35 am

Re: How to test Overdrive Solenoid on '41 120

Post by Howard56 » Thu Dec 10, 2020 3:42 pm

I do not anymore. Only place I knew of that some have used for assorted small motor, switch and general electric parts rebuilding appears to have closed. If the unit you bought from Max is not working I would hope they stand behind their product and that would be my first suggestion. Kanter also does rebuilding of some items but I do not know if solenoids are among them.

flackmaster
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Joined: Thu Aug 20, 2009 8:12 am

Re: How to test Overdrive Solenoid on '41 120

Post by flackmaster » Sun Dec 13, 2020 7:13 pm

From Memory (fading/failing) there is an auto electric shop in Florida that can work on an R9 solenoid.

Packard7
Posts: 17
Joined: Sat Aug 13, 2016 7:30 pm

Re: How to test Overdrive Solenoid on '41 120

Post by Packard7 » Tue Dec 22, 2020 10:55 pm

I’m not sure if this will help but I spent a month tracing the wires only to find out I was using the wrong diagram for my overdrive. As soon as I used the correct wiring schematic it was obvious I had the wire on the solenoid attached incorrectly. Now works fine. There is also an in line fuse close to the firewall.

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