The Stovebolt Site Forums The Shop Area Driveline Overdrive electrical question

I have been running a 3 speed W/overdrive on my 283 in the 58 Apache for 13 years now. I controlled it with a cable and a switch, bypassing the governor completely. I don't know how I lived without it. Now I want to incorporate the governor and it is working.
According to the '57 Chevy car manual there is only a cable used to actuate the overdrive.
Studebaker and Plymouth had a rail lockout switch on the overdrive that prevented the governor from actuating the solenoid when not in freewheel mode.
Did Chevrolet have a different way of locking out power to the solenoids while not in overdrive or did the system just energize anyway every time the vehicle went over 28 miles per hour?

Yes. Ford used an electric switch at the accelerator pedal, and Chev used a bracket at the Carb mounted so that the accelerator linkage hit the switch at the top of its movement.

http://www.fifthaveinternetgarage.com/overdrive_parts.php

The switch they sell can be used in either the Chev configuration or the Ford one. It is easiest to just put it under the accelerator pedal, but making a bracket for the Carb mounted one is not that hard.

Most everything you need to know about the R10 Overdrive is here: http://devestechnet.com/Home/HowTo#driveline

You NEED that switch. If you put it in reverse just once without locking it out first, you will have major damage. It's just not worth it to go without it.

http://www.fifthaveinternetgarage.com/pdf/relay_kickdown%20instructions_update.pdf

The cable is totally unnecessary for OD operation. Some people lock them into the overdrive position with a short piece of welding rod bolted from the lockout lever to the transmission housing. The planetary unit locks itself out automatically when reverse is selected, as anyone who has ever been inside the B-W overdrive unit knows. The only purpose for the cable is to lock out the OD when you need compression braking, like on a long downgrade. There is a lockout pin that is moved by the internal shift linkage when reverse is selected. The only difference between the SM-318 case and the 319 case used with the OD unit is one hole drilled in the case for the lockout pin. I have converted several standard 3 speed transmission cases to OD by drilling that hole.

I strongly suggest you listen to people who have hands-on experience, not just a good internet search engine.

PM me for a good electrical diagram to make your OD work like the factory intended it should.
Jerry

That switch is only for the kickdown function, and is not connected to the reverse or lockout functions, which are mechanically controlled as Jerry states.

The really scarce OEM item in the electrical control circuit is the relay, but a regular Bosch-type relay can be substituted if the circuit is wired properly. A spring-roller Micro-Switch can be used for the kickdown with a little creative bracketing. The normally-closed contacts on the relay momentarily short out the ignition to unload the drivetrain and allow the OD to disengage.

The Chevy OD engages automatically anytime the governor contacts close, (about 30 MPH) unless the OD is mechanically locked out with the cable.
Jerry

I have a friend that is really wiring his wrong then, because if he don't flip that switch before pulling out of the garage, it's over. He constantly complains about it. "$1000 here, $1000 there, its ridiculous!" I haven't bothered to see what's up, but it's apparently possible to bring upon yourself a whole world of hurt with a switch. I just use the official wiring diagram and move on. If people just do what the factory states in the manuals, there are no issues. It's a great little transmission.

Thanks so much for the helpful responses.
Let me rephrase my question since im still a bit unclear.

According to Borg Warner;

"In some applications before 1951, a reverse lockout switch was located between the kickdown switch and the governor. The reverse lockout switches were discontinued sometime during the 1950 model year and can be eliminated in prior year applications. No replacements are available. The wiring connections will be the same as explained above."

Their wiring diagrams show a manual switch to replace the early style transmission mounted reverse lockout switch. Is that the way the 51- and later systems all worked?

What has caused this confusion for me is a 1957 Chevrolet manual never mentioned this switch, just shove her down into overdrive and go ....basically.


That had me thinking Chevrolet wired it so the governor will always energize the solenoid in both freewheel and direct drive without a manual switch to prevent it.

I guess the author of that 1957 manual was thinking of the pre-1950 models?

Mr. Jackson, who built it for me said never tow in freewheel, so the cable is definitely needed for my application.
It's worked great for 13 years so far wired wrong, but after driving my '50 Studebaker working as Borg Warner designed it, I'm motivated to incorporate the relay and governor unit, but don't have much use for a working kickdown switch. I'm old and in no hurry to get places anyway.

Yes, you need the kick down switch. Think about hills. I used a DPDT switch and a Bosch style relay.

wiring diagram.

Yes, you are correct in thinking the solenoid is activated even when the unit is locked out.

"Yes, you are correct in thinking the solenoid is activated even when the unit is locked out."

THAT's what I wanted to know.
Disturbing as it is ....
That solenoid shouldn't be pulling juice for nothing during those times when you don't need it. It's downright wasteful!

I referred back to the schematics in my '65 Motors manual, and they show no manual dash switch like the Borg Warner schematic does. I'm going to keep the manual switch for those long hauls in direct drive. Then I'll add a relay and tie in the governor.

Rusty has taken me from South Texas to the pike national forest and also to the Atlantic Ocean, all without a kickdown. (I didn't mention He's got a 283). Mr. Jackson who built this transmission for me back in 'o3 warned me that using freewheel as a passing gear is hard on a set of particularly small needle bearings somewhere, so I'm not in the habit of using it that way anyhow.

I like those fentons on your GMC, I put a set on my '59 Viking short bus to replace a cracked manifold, and they sound great!

The switch you are referring to on the older vehicles is to prevent engagement of the solenoid in when shifted into reverse.
It is not the kick down switch which serves a completely different purpose. Ford, Studebaker, Plymouth, and others used this system on early vehicles.
GM, Ford, and other later units use a lock out pin as Jerry mentioned that is actuated when shifted into reverse.
If you hook up the wiring using the relay, KD switch, and the governor as the factory intended for it to be, anyone can drive it and it will perform well. I don't know what "using freewheel as a passing gear" means. It literally makes no sense.
The only control on or near the dash is the pull cable so you are not going to find any reference to a switch on the dash.
You are free to use any configuration that makes you happy but some actual engineers devised the system years ago and it continues to work well if installed as intended.
Fred

It would seem that getting a vehicle up to 30 MPH in reverse so the OD solenoid could engage when the governor contacts close would have hazards that would make accidentally engaging the overdrive way down the list of possibilities!
Jerry

Thanks for all the helpful info guys.

I pulled a fan relay from a 74 Chevrolet truck and a pull switch from a snorkel lift truck at the junk yard.
I wired it all up according to the Borg Warner schematic minus the kickdown and it works beautifully as before only now I can now get around town only using the clutch from a dead stop.
I wish I had done it this way 13 years ago.
I appreciate all of the good advice!

Thanks for the clarification.
Being lazy, I am a strong believer in not re engineering things. Seen people blow up perfectly good engines trying to outrun the next guy. Longevity is my goal.

The point of confusion for me was that the engineers did away with the reverse lockout switch and didn't provide an alternative way to prevent solenoid engagement.
I frequently pull trailers, dead cars, and vintage travel trailers in direct drive, otherwise I would be unconcerned.

With a proper factory setup, when you pass using the kickdown you are essentially dropped down into freewheel at that point. That's what I meant by using freewheel as a passing gear.
I rarely pass, so I'm just as happy without the extra complications.

I think you are confused about the freewheel feature. When you engage the kickdown switch you are essentially bypassing the overdrive function and reverting back to direct drive. Freewheel has absolutely nothing to do with anything during this operation. If you are driving in 3rd overdrive and press the accelerator to the floor it will shift the transmission into 3rd direct until you let off of the gas and then it will shift back into 3rd overdrive.
There is a slight pause (freewheel) when you let off the gas while in gear before the transmission shifts into overdrive.
In most cases it is not even noticeable.
The system will also go into freewheel when you slow down under about 30mph. When you stop and take off again you will be in direct drive until you get up to speed for the OD to engage.
These transmissions also lock out the planetary gear as part of the reverse lock out function. When the cable is pulled out for direct drive the solenoid or any other overdrive components will not engage.
Fred

My impression is that the only way to return to direct drive is to stop completely and pull the cable out.
Either way I'm very happy with it without the kickdown switch.

Your impression is incorrect. If done correctly the cable can be used to engage or disengage the overdrive while moving. When you start out from a dead stop with the overdrive cable pushed in you are in direct drive until you reach sufficient speed for the overdrive to engage.
As mentioned previously the general practice is to leave the system engaged except for towing or driving down mountain roads.
There is a massive amount of information on this site regarding the operation of overdrive transmissions. Ford, Studebaker, Hudson, Rambler and other sites have similar data as they used overdrives for many years.
You can also find this information in the shop manuals and vehicle operation booklets.
Properly wired and operated overdrive transmissions will perform well for many years trouble free.
Fred

If you don't have the kickdown switch you will need to stop or get below 30 to pull the cable. I don't understand why you are so stubborn about not wanting it to work as designed.

I agree with Fred about "Properly wired and operated overdrive transmissions will perform well for many years trouble free."

It is only due to my laziness pure and simple.

If I already had the linkages and the proper four pole switch in hand I might make the time to install it, wire it up and adjust it to work as designed. I'm not against having the feature at all. I may eventually cross paths with the right hardware at a good price but until then I will muddle through without it. Not having it hurts nothing.

Stopping to engage direct drive is no problem for me because I only use it when towing. Been doing it that way for 13 years all over the continental US and never met an incline Rusty couldn't climb.

You can get a switch from Rock Auto for under $4.00.
Airtex/Wells ADV 4C2, 1984 Chevrolet El Camino stoplight switch.
Pick up 2ea 1/2" NF jamb nuts for the switch. Fabricate a bracket to mount on the front of the carb to actuate the switch at WOT. Wire it up and you are good to go.
Fred

I'm incredibly grateful and appreciative of all the excellent advice here. Thanks everyone.
I've never encountered quite this level of helpfulness before!

I was fortunate when I bought the overdrive trans for my 58 Suburban. The seller had the entire wiring harness pulled from the donor vehicle (67 C10) and zipped tied ready to go. I got the relay, kick down switch, all the wiring and all the parts for the overdrive (solenoid and governor). I probably paid a little more than I needed to but the seller had driven the vehicle it came from and could vouch for the operation of the overdrive. It was complete and ready for installation.

I wired mine slightly differently than the factory diagram. I have a 78-79 250 with HEI ignition in my truck. I couldn't find any way to attach the kick down switch to the carb. My fab skills are pretty non-existent. I ended up mounting the switch (a simple push button thing) in a spare hole I had in the dash. Also, with the HEI there is no place to hook up the ignition shorting wire like on a points ignition. In order to drop out of overdrive back into direct drive I just have to push the button on the dash by hand and let off the gas for a second so the solenoid can disengage. After a second or so I step on the gas and it runs in direct drive. As soon as you let off the gas again the solenoid fires and it goes back into overdrive. Took a little practice but it works like a champ. This is very handy for highway driving when you need to go up a hill or need a little more power/torque to pass.

The other change I made (based on advice from another Bolter) was to add an on/off switch inline between the kick down switch and the solenoid. When left in the on position the overdrive functions normally and I use the kick down button as described above. When in the off position it kills power to the solenoid so it can't go into overdrive. I found this very handy when cruising local roads and coming into a town or something. Instead of pulling/pushing the cable to disable the overdrive, I can just temporarily do it by flipping the on off switch. When I'm out of town and back on the open road I turn it back on and it works as designed.

The only "interesting" byproduct of my installation is that with pull cable in the on position and the on/off switch in the off position (temporarily deactivating the overdrive) the transmission free wheels at any speed. There is no engine braking at all like there is when in direct drive or overdrive above 30 MPH. It allows me to coast along when not accelerating. Another feature that took a little getting used to but is very handy.

The little clip that holds the end of the pull cable housing to the transmission is a bit wonky and doesn't hold the cable housing very well. After pushing/pulling the cable a few times it tends to slip in the clamp and then I have to crawl under the truck to fully lock in/out the overdrive. That is why I really like the on/off switch. I leave the cable in the overdrive position all the time and just turn it off electrically when I don't need it. If I ever tow something I'll make sure to use the cable to lock out the overdrive. One of my short term goals when I get my truck back is to figure out a better cable clamp so I can really use the cable as intended.

I'm hoping that I'm not somehow endangering my overdrive with the on/off switch. I drove the truck for about a year with that setup and never had an issue.

All that being said, IMHO you really need to have a kick down switch or some other way to disengage the overdrive other than the cable. Right now it sounds like you just drive around in overdrive all the time and don't have any option for direct drive other than pulling/pushing the cable. I guess it will work that way but it really limits the driveability functionality and benefit of having the overdrive. I would be concerned about wear and tare/load on the overdrive planetary gears. It takes a lot of force to move a truck from a dead stop. Much less than dropping into overdrive at 30 MPH. I would think you would be banging pretty hard on those gears every time you take off from a dead stop while in overdrive.

Just a different option for you to consider.

I wired it up just like the Borg Warner schematic utilizing the governor.
I pull the cable into direct drive when pulling the Airstream Overlander, or trailering my '40 Ford 9N.

For light hauling I'm leaving the stoplight in 1st gear in freewheel but the governor is preventing the solenoid from engaging overdrive. I accelerate to roughly 10 mph, then abruptly let up on the throttle. When the engine RPMs synch with second gear I then slip into second gear like butter. At 27-1/2 MPH I repeat the process, and at 37 or so I MPH I let off the throttle finally going into actual overdrive.
I'm retired an in no way in a big hurry, but If I encounter an unexpected mountain or Sunday driving blue hair, I can always shift into overdriven second gear.

When I come to a stop it easily slips out of gear once the governor disengages the overdrive solenoid well below its set point.

If I want to be a speed demon I have another Chevy.
It's a '38 HD sitting on a square body Cheyenne with a 454 shoehorned under the hood. It's REAL fast, and not directly my doing other than giving an unmolested original truck to my meddling father.
It's okay because I still have another '38 HC for proper restoration. (With extra full driveline and two extra chassis)
Now my Studebaker has the small flathead six with factory overdrive all properly installed with kickdown working smoothly as it should. It desperately needs it since it doesn't have the power of a 283 small block.

Once again, there is no such gear selection known as freewheel!
Fred

Thanks for your help.

You need the kickdown switch if for no other reason than to be able to disengage the cable while the vehicle is moving along. The cable cannot be disengaged while the vehicle is moving. You have to come to a complete stop before you pull the cable to disengage overdrive, UNLESS you engage the kickdown and pull the cable out while doing so. Then you would be in direct drive again. ...Belive me you will need to that from time to time...

I've never had to kick it down to lock out the overdrive while the truck was rolling. As long as you're under 28 mph (give or take depending on tire diameter), and the solenoid isn't engaged, you can shift the lockout wile rolling no problem. I do find it a good idea to pus the clutch in when doing it, though.

I have a side conversation going on with Deve about how to wire the ignition grounding wire into an HEI distributor. Interesting stuff!

This got me thinking. I've never spoken to someone that has the system installed on a points ignition as designed specifically about the kick down process. So how exactly does the kick-down process work? Do you punch it quickly to the floor to hit the switch and then hold it there? Do you floor it and then release the gas pedal to allow the transition? I would think that if you left your foot all the way down when the the tranny drops back into direct drive and the ignition re-energizes you are at wide open throttle. I wouldn't think you would want to do that. My follow on thought is that if you immediately ease up on the gas so your not winding the hell out of the motor at WOT, the tranny would probably jump back into overdrive. I'm very curious about how the transition back into direct drive works on a "factory" installation. I have the transition into overdrive down. As soon as the load on the tranny reaches neutral buoyancy the overdrive will engage. That works great on my truck.

Bottom line is I may explore how to gain the factory kick down functionality on my HEI distributor. The hand operated switch works fine but it may be nice to hands free operation. The is pretty far above my skill level. :-)

From an old BW service manual that I have:
When operating in overdrive, the driver may require the return to direct drive without reducing the car speed below the cut-out point. If the accelerator pedal is pressed down beyond the position corresponding to wide-open throttle, the stem of the throttle (kickdown) switch is pressed, thus opening that part of the control circuit between the governor and relay, whose contacts points open, de-energizing the solenoid, the outer spring of which urges the pawl toward release. Due to the fact that the engine is driving the car through the gear train, the pawl is pinched by the torque reaction and cannot release until the driving torque is removed.
That's kind of a long winded version but yes, once you engage the KD switch it will hold the transmission in the lower gear until you let off of the gas.
Fred

The person I would ask about this is Tom Langdon. He sells distributors with built-in coils for HEI and I think he might know how to get the negative side of the coil accessible for interrupting the signal. The units I make have the can-type normal coil so it will work fine without doing anything. Tom could probably tell you right away how to do it. No sense in reinventing the wheel if Tom has the answer.

I'm greatful to the gurus here who helped in finally get my governor wired in and thrilled with it the way it is for now. I'm all for a proper kickdown as soon as I get caught up with bigger priorities, like putting my '38 back together.

When I run across the bracketry I'll get a reproduction electrics if I have to. I like it to look period. Rusty has untold thousands of miles and 20 years on a rebuilt 283. He's just starting to blow a little smoke so it's almost time for an overhaul. lots to do.

Before, the overdrive cable was only moved at the beginning of the journey depending on city/highway or Heavily loaded/ unloaded. Somehow I muddled through without the governor or relay just fine. From now on It's going to stay engaged even in town since it's easier on my knee. I tried to go into direct drive while in motion and the solenoid de energized only one time about ten years ago and it growled a little at me. The clutch wan engaged at the time, but I never had a reason to go into direct drive that couldn't wait until the next necessary stop.

It turns out I was sold an extreme race cam for the 454 instead of the stock one I ordered for the '38. The new stock cam is making good compression now so once it's all back together and the front clip is back on I have a laundry list of things to fabricate for this nightmare. When this Frankenstein is done, Rusty is going into semi retirement. I'm not planning on hauling anything more than an old canned ham camper.