Re: The Duchess Project: 1940 Super 8 Convertible Sedan

Posted by Joe Santana On 2021/1/31 12:15:02

I edited what DC wrote the following to me in a PM regarding the OD. I will answer his questions in the next post.

OD

Took a peak at the wire diagram found on this site. Then reviewed the service training manual. Then went back a ways in your project blog to about pg 95.

Good luck with the endeavor of the Duchess being your daily driver. I commend you(and question you).

With the overdrive seems like you have had a number of different symptoms. Before setting up a couple of simple tests to check for the flow of current would you confirm a few things?

Is this vehicle still a six volt positive ground?

Did you say previously that the od problem was first a creep out of disengaged toward engage and click/grind? Then the od would not engage for a time? Then sometimes no disengagement slowing from highway?

Now I see it will engage but not kick down , correct?

Some of these suggest mechanical issues not electrical. Looking at the schematic I see the govenor breaking the primary control circuit. This should disengage automatically every time slowing below 22 mph.

Why the need to manually disengage upon deceleration? No stalling should occur.

If this were mine I would do some simple mechanical tests, then proceed to electrical testing. First step of diag/repair is to review normal operation and note all symptoms. So what are the malfunctions occurring at this time?

Just looking at the schematic and service manual I would like to note a few things.
The actuator(solenoid) needs to have a a good chassis/ transmission connection as you have experienced this with your VR above. This “ground” as we call it is positive here and the solenoid windings and contacts need this for completed circuit and current flow. Rusted bolts, paint etc will be issues here. Both windings will need to be energized to create strong force of engagement.

I see the ignition cut out circuit and am aware this needs to function for a split second on kick down. I am curious about your muffler explosion and that of another poster in this thread? Can you explain the conditions in which this occurred? I wonder if this has all been addressed on another thread before? We can do this on your blog if you like?

First tests would be mechanical ones then fairly quick tests of the contacts with a test light from the relay terminals and a couple energizing the solenoid coils with one wire removed with jumper. I assume the control relay is accessible on the firewall? The solenoid is on the side of the trans OD unit as well as the governor so these are challenging.

The wiring diagram posted with the description above is a simplified one . I will be attaching a more accurate. There is a contact inside the solenoid cover that also controls the ignition cut out as well as other contacts opening and closing with plunger position. These will need to be tested.

BTW - carbs overflowing from float issues are a very dangerous fire hazard. They also dilute engine oil with a lot of raw fuel passing the piston rings! This is an engine killer. Bearings and cylinder scuffing through wash down. I hope you changed the oil! I saw no one mention this on your blog and am not sure how much experience you have as an auto mechanic. I guess you are having fun through this learning process. Old cars!
Cheers! DC