How to operate R-10? Non-Electric Overdrive...

[bamfordsgarage]

I am helping a friend sell his low-mileage 1950 Plymouth. The car was parked for 2-3 years, but fortunately had a fuel stabilizer treatment back then and last week started and runs fine.

 

An overdrive was installed two owners back. I believe it was an R-10 type, can't be sure. In any event, electric controls were never part of the install. The fellow who sold the car to my friend gave him a tutorial and we used the overdrive regularly, including one very successful run down to the PNW in 2016.

 

Anyway, friend and I have both forgotten the operating sequence for shifting out of overdrive. Shifting in is easy: push in the handle, let up the gas briefly above kick-in speed and we're in. Shifting down needs help... yes we can coast down to below kick-in speed, but that is counterproductive when approaching a hill (the period manual instructs the driver to engage the electric kick-down but that is not an option here).

 

We believe there was a non-electric technique for shifting from O/D to direct while at speed, but I would rather ask the experts than chance doing harm to the car. Is there a safe technique using only the handle and gas pedal? Or are we remembering something that never actually happened?

 

 

 

[Young Ed]

If I remember Dads driving correctly he would occasionally flick the ignition off to get it to kick out. 

[61spit]

I think there is supposed to be kick down switch on the carburetor that the linkage hits when the accelerator is pushed all the way down. That kicks the OD out of gear and then when you reach the speed you want and let back off for a second it shifts back into over drive. I think the handle is only to enable the OD or completely disengage it. Isn't used to shift in or out of overdrive on the move.

[bamfordsgarage]

Thanks guys. This particular car has no kick-down switch installed. I have since found some wiring and a relay and will investigate further. 

 

On my original question about shifting out of O/D without slowing down to the kick-in speed, the following note is on a George-Asche hand-written wiring diagram:

 

"When moving cable in or out have the car pulling (not coasting) or have car stopped"

[greg g]

I have mine wired according to George's schematic which is available in this sites download section.  I don't have a kick down switch.  So the governorship is to activate the ground connection for the solenoid.  The solenoid has two functions, the pull in circuit which engages the od, an internal set of points that engages a hold in circuit. When the hold in clicks in it releases the pull in.  Both are grounded through the governor if you interupt the ground the od drops out.  The pull in takes about 10 or 12 amps so it needs a healthy wire to provide current, the hold in requires 4 or 5 amps.  My understanding  is kick down was initiated when you floored the gas pedal as you would do in passing a vehicle, or anticipating a long hill.  So that language from George about shifting out of OD under a load makes sense. I admit I usually shift in and out with a slack driveline.  I power the switch circuit of my relay through a switch through a 10 amp inline fuse from the accessory connection on the ign switch. That switch is located on the signal light housing. If I need to shift out of OD with urgency, I usethat switch to depower the relay.  I can't remember but I think the governor ground connection runs through the push pull cable terminals. Got 10 to 12k miles with no faults.  Hope that makes sense. 

[bamfordsgarage]

Thank you Greg, on first reading that seems to make sense. I will study it up further and check the wiring further. 
 

But first a 200 mile round trip to the Red Deer AB swap meet tomorrow. Looking forward to the o/d on all that four lane. 

[Robin (UK)]

George's description is correct.
When the transmission is under load (not freewheeling) you can pull the OD handle to lock out the overdrive.
I use mine like this regularly.

[bamfordsgarage]

On 5/3/2024 at 1:59 AM, Robin (UK) said:

...When the transmission is under load (not freewheeling) you can pull the OD handle to lock out the overdrive.
I use mine like this regularly.

 

Thank you Robin. When I have experimentally pulled on the handle at speed in OD, it didn't want to move and I feared some mechanical mayhem if I insisted.

 

To clarify: you can/do pullout the OD handle when the car is in OD and in motion at above the kick-in speed (and, of course, under load)? And if so, does the OD kick out immediately or wait until the accelerator is released?

[Loren]

In my mad mind there is only one way to operate an Overdrive, that is as the factory intended. The thing is called Automatic Overdrive for a reason.

It works so well without drama when installed properly I just don't understand why anyone would jury rig one, except ignorance of how to wire one properly.

I've never stopped looking for easier cheaper cleaner ways to do it right. Throttle switches are way over priced from suppliers who think they have you over a barrel.

At $125 I think that is obscene. I found a seller on eBay who had hundreds of military surplus bus door switches that do exactly the same thing as the reproductions and even looks the same for $6.50 ( I bought 10 for gifts to friends ) The reproductions are really floor switches for Ford products anyway. The MoPar switch is smaller and fits on the carburetor. Those can be had from the Studebaker guys for around $35 but you need to make a simple bracket and rig a lever on the carburetor throttle ( or find an Overdrive ready carburetor ). My latest and greatest find is a small switch with a pull cable from a Nash/AMC for $21. I really like this one as it is so clean and simple. Since you connect it to the lever that comes from the foot pedal its action is really smooth and effortless. You can change carburetors and manifolds without re-engineering how you trigger the switch.

Then there's the relay, another obscenely priced item at $125. If you have changed to 12 volts one of the little Bosch style cube relays will work nicely for about $2.50. I like my 6 volt cars and found the same thing made in Germany for 6 volt for $18, but I am told the 12 volt version will work with 6 volts if you get the high amp version.

The last thing is how to wire it. If you have a shop manual there's a description which also has the color the wires should be in there. Seems to me the only valid reason for not having a shop manual is illiteracy ( trust me I am not joking on this. Literacy is still a major problem especially in auto repair ) I have found that sometimes the Plymouth manual is short on an explanation and photos so I have all the MoPar manuals for the era of my Plymouth. But then I love shop manuals. I am the person your Mom told you about who reads technical manuals for entertainment. lol

Anyway that's my two cents. If it works as intended you are not dependent on "Driver technique" and you can let anyone drive your car ( but why would you let anyone drive your car? )

[kencombs]

Well, IMHO factory with a mod or two is the way to go.   There is a way to implement full auto with an override that allows an electrically operated downshift without a full throttle lunge.   Especially handy when anticipating the need to pass or before actually lugging down on a steep hill.   Much better for everything to avoid full throttle whenever possible.   Simple switch that mimics the throttle switch.

[Booger]

Those of you who are lucky enough to have an R10 OD should have the Randy Rundles Garage Tech. 

[bamfordsgarage]

More helpful posts. Thank you all.

 

Wise words from Booger, and in fact Plymothy Adams sent me a link to one of Randy's blog posts earlier today.  Man, what an informative site. Very very helpful. Sad to read he passed several years ago.

 

Loren, I get your point that the factory setup works well and why try to re-invent the wheel — in this case, the car is not mine, it doesn't have the full factory setup and hardware now, and my goal here is to gain a working understanding of how this particular install should be operated, strictly as an aid to the sale of the car.

 

Having said that, I've had an R-10 overdrive in the garage for years, intended for my '47 D25. This situation with my friend's car is inspiring me to get on with that project. That unit too has no lockdown switch, and I favour Kencombs suggestion of an override that does not require a full-throttle lunge.

[bamfordsgarage]

23 hours ago, Loren said:

...you are not dependent on "Driver technique" and you can let anyone drive your car ( but why would you let anyone drive your car? )

 

Fair point, and while most folks wouldn't, some encourage it 🙂. As it happens, a favourite annual event for me is the so-called Inter-Club Ride/Drive which is coming up May 25 (since 2017, Covid-excepted).

 

Four clubs converge on a casino parking lot adjacent to a quiet industrial area on Saturday AM. Basically a "cross-cultural" car show with no public spectators and an unusual twist... No pressure, but owners are encouraged to offer a ride experience in their cars to others, and many choose to exchange drives as well. This is, for me, a total hoot. I've given many people their first Model T experience, riding and/or driving, and had the pleasure of wheel time in a Bugeye Sprite, Tesla X, '50s Rolls Royce, Model A roadster, Triumph TR4A, NSU Prinz, Tesla S, electric moped, MGB, '53 Buick and many more.

 

Here is a photo gallery from the 2022 Ride/Drive. First photo is a young fellow club member giving a Rolls-Royce collector (front seat) and two sports car guys their first Model T ride in my 1926 Touring.  The Rolls-Royce fellow brought the black and yellow RHD rig seen further into the gallery — and with somebody else at the wheel!

[Loren]

My love of old cars started with the Model T. I have a 27 Roadster and a few others. The Model T driving experience is not one I’d offer to just anyone however!

I sold a 27 tudor to a guy and gave him the whole driving lesson. A week later I got an email describing how he pressed down on the low pedal thinking it was the brake, drove into another car then took his foot off the pedal. I am glad he didn’t send me a photo.

 

My philosophy of old cars is we are stewards of them for the time we have with them. They can certainly out live us if we are careful with them or we can destroy them in a split second. When you consider the history of the world since your 26 was made it is remarkable that it is still here, let alone the human race.

When someone goes on about how they want to put their Plymouth body on an S10 chassis, I cringe. That ole Plymouth could live on for decades and still be a nice car. Once someone “modernizes” it, it has taken a big step to the scrap yard. Consider the car magazines of the 1950s. Where are all those “Customized” cars that graced the magazine covers now? Survivor cars got that way because of the stewardship of a chain of owners. In some cases it was just benign neglect that contributed.

Cherish your old car and it may out live you!

[Robin (UK)]

On 5/4/2024 at 3:36 PM, bamfordsgarage said:

 

Thank you Robin. When I have experimentally pulled on the handle at speed in OD, it didn't want to move and I feared some mechanical mayhem if I insisted.

 

To clarify: you can/do pullout the OD handle when the car is in OD and in motion at above the kick-in speed (and, of course, under load)? And if so, does the OD kick out immediately or wait until the accelerator is released?

To clarify, my OD is wired though a push button which activates a latchable relay. This could be replaced by a switch, so for this answer I'll call it a switch.
Assuming you're in 3rd gear with overdrive engaged, the handle will be pushed in and the switch will be on.

To come out of overdrive:

• Turn the switch off (to cut the electrical supply)
• Release the gas pedal, to allow freewheeling

You'll now be out of overdrive, in 3rd, but the transmission will freewheel when not under load

 

To get back to direct drive

• Press the gas pedal to load the gearbox
• Pull the lockout handle out

I hope this helps.
Robin

[bamfordsgarage]

1 hour ago, Robin (UK) said:

...I hope this helps.
Robin

It does. Thank you Robin.

[greg g]

Don't reverse with the od engaged.  Some have mentioned a slide rail extension or similar to disengage od, if mine has it, it doesnt seem to work.  Mine is a 54 od on a 56 trans.  Makes expensive noises if I try to back out of the garage with the cable in od on position.

 

maybe some one can explain with visual aides included.

[kencombs]

48 minutes ago, greg g said:

Don't reverse with the od engaged.  Some have mentioned a slide rail extension or similar to disengage od, if mine has it, it doesnt seem to work.  Mine is a 54 od on a 56 trans.  Makes expensive noises if I try to back out of the garage with the cable in od on position.

 

maybe some one can explain with visual aides included.

Is your main case and OD case?   Non-OD cases do not have the hole for the lockout rod.

[FarmerJon]

'55 OD case on Left, '47 standard case on right.

Purple: countershaft+reverse idler.

Green: Shift fork rails and Guide

Red: tailshaft extension mounting

Blue: Oil drain back, OD only

Yellow: OD shift rail/reverse lockout

 

Despite the difference in outside profile, you could use a standard case on an OD, but would need to machine 3 holes, or modify the OD shift rail. 

 

 

 

[greg g]

The 56 trans was not an od equipped unit.  So I guess that's the rub.  Thanks for both responses.