I’m building an old school rod, kinda like a T bucket, but bigger and hopefully a little more room. I’m using a Packard OD trans, converting from 6 positive ground to 12 volt negative ground. Means replacing all of the OD parts outside of the trans, got to thinking…. I know! There’s the problem, right there… The actual shifting is done by the solenoid. Seems with a single bit of linkage, that could be replaced with a shift lever… Has this been done, tried, or thought of (can’t imagine that).
Dave is spot on. Put a resistor in line before the solenoid that has the same resistance as the solenoid (guessing somewhere from 1.5 to 5 ohms). Thank's to Ohm's Law, the voltage is cut in half, just make sure the resistor can handle the power. 12V x 15 Amp fuse = minimum 180W resistor. About $3.64 through Digikey right now.
There is more to the solenoid shift that just moving the plunger. Done wrong it could damage the gears. When the solenoid moves the ignition in also interrupted to remove power. 12v solenoids are not cheap, but are available. Resistor is a better choice IMO.
^^^^^^^ Well, kind of ... it triggers the relay which grounds the dist. for an instant. Gear damage occurs when something happens to leave the OD engaged mechanically when in reverse. Most, if not all of the '40s - '60s R 10 & R11 have a pushrod which mechanically dis-engages the OD so that can't happen.
You pull the handle to engage and the wires to disengage via the throttle kickdown. Since I always new when I was going to pass or needed to disengage - I just used a little clutch and push the handle back in.
I ran the Hudson on 12v, it worked fine. This was after switching the rest of the system from 6v PG to 12v NG. I did quite a bit of research first, and it seems that folks who just go ahead and believe it will work, don't have any trouble with the solenoid, or the relay. And you probably want to keep the electric stuff set up as designed, it turns out the folks who built these things, did a great job. Make sure to include a kickdown switch that both disengages the solenoid, and kills the ignition momentarily.
My application uses a BW R11 overdrive unit. The electric power relay drives two circuits, I understand they are different voltages or amperage, one to pull it into OD and one to push out of gear for passing, as I understand it. I believe there is more going on than I understand and.. well, just simplify… seems if it was really as simple as I’m imagining, someone would have done it by now. And could report success or failure…
The system is kind of complicated, and it will take a while for you to really understand how it works. The same electrical control system, with minor variations, was used by most car makers over a span of a few decades. It's a proven design. And all the parts are necessary--they would not be there if they weren't. Driving a car with a properly working BW overdrive is a really neat thing. Have some patience. Don't try to "improve" it, by removing parts. They're all there for a good reason.
Jim, truer words were never spoken. There’s quite a bit of incorrect information in some of the replies in this thread. Bad “facts” can lead a person down a rabbit hole if they don’t double check those statements…..
You can't easily handle the OD shift with just linkage. To shift from direct to OD, you have to move the pawl into a notched wheel which locks the sun gear to the case giving you OD. This is done electrically with a combination of the solenoid and a device on the sun gear wheel called a balking ring. It's all about timing. When you let up on the throttle, the balking ring acts like a synchronizer preventing the solenoid from pushing the pawl in until the sun gear just starts to move counterclockwise. At this point the balking ring moves just enough to let the pawl engage the sun gear wheel without any ratcheting.
I am with squirrel on this one, I converted my 49 Studebaker to 12 volt 15 years ago and used the stock solenoid as is and it is still working fine! I did use a modern ISO relay not because I had to but because the old relay was toast. Used the stock 6V starter as well, no problems.
my OD switch. My set up uses a 2speed rear end motor to engage the OD. Used a 2speed rear switch and wiring from NAPA. Don’t know if this helps you any. The switch has power in and 2 power outs. My OD is probably different than your solenoid type. I have 2 Stude R10s I plan to use. so I’m following the answers here. To operate mine (the non solenoid type) I ease off the gas and hit the switch. Both to disengage and activate the OD. I understand the factory interrupted the ignition (or something like that) for the OE applications. Plus switches and a bunch of stuff to disengage with the gas pedal is in a certain position. I guess kinda like a kick down for passing. Us hot rodders are disciplined enough not to need all the BS the factory used. I was under the impression with my R10 that I could hook up the OD lever/cable and a switch to the solenoid. Haven’t tried it yet other than a simple bench test. my r10 I plan to use is 6v. The plan was the knock the voltage down. For the polarity. Could an “H bridge” be used? Maybe the electrical gurus know.
https://fifthaveinternetgarage.blogspot.com/2017/01/borg-warner-r-10-and-r-11-overdrives.html?m=1 Not any wiring help, but some operation instructions just incase.
The OD lever will either lock out OD by moving the teeth on the sun gear into splines on the planet carrier. That locks up the OD gear set and you have direct drive. Moving the sun gear in the other direction will allow the OD to operate, but it does not shift it into OD. You still need to energize the solenoid to shift to OD. You can use a grounding switch in place of the governor. The ignition interruption is only for the kickdown feature at wide open throttle.
The ignition interuption serves to remove the torque load from the plunger, otherwise solenoid doesn't have enough power to move it when under load. I've used a switch to replace the kickdown linkage to activated one. Usually placed on the shift lever or steering column. I much prefer to downshift in advance, and use moderate throttle to accelerate. It's especially nice when used in a pickup or towing. You can select direct drive when approaching a hill or when merging into traffic. Just feels so much better than having to stomp it to the floor.
When I put OD in the Edsel, I had a microswitch near the steering wheel to activate the kickdown. R11 might be fine for towing, etc but R10...no way
Thanks for all the discussion, guys. I appreciate all of the input. I really like the tech articulate by Randy Rundle, very helpful… I think the kick down switch is going to go, as is the solenoid. I think the lockout must remain in order to remain in 3speed mode for in town, so will have engine breaking… Hopefully, that’s all the ‘breaking’ that will occur…
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