What'this overdrive 1934

B

B-nut

Senior Member
My new 34 has an iron overdrive unit welded (very neatly) into the drive shaft in front of where the radius rods tie in.Cast into the side is W G DIV n2. Under the dash has the electric switch and 3'' lever to actuate. The hot wire to the battery is disconnected. Can you tell me what kind of overdrive this is? How does one operate this?Manuals must be out there. Shall I just flick the switch an pull the lever while proceeding slowly down the road? Tempted to start playing around.What weight oil should be in it? Car has been a storage for a couple years.What ratio might this overdrive be? The differential gear is a 4:11. The car has the standard 600x16 tires. Thanks for any advise!
 
B-nut, 33 & 34 had 17" rims/tires standard. Next need photos for everyone to look at to see what you have, only option for overdrive in 34 was a Columbia in the rear axle. What you have is an installation by someone in past. Let us see it, Bruce
 
You may want to post the photo even look in the V8 Times at the Mitchell overdrive. I believe the Mitchell is mounted on the torque tube closer to the pinion. I would not connect wires or try shifting without knowing more about the unit.
 
I agree it is most likely a Borg Warner OD. Push the handle in toward the dash and see if the car "freewheels" when you let off the accelerator as you drive. If so, it helps to confirm the ID. It should act like a normal transmission when the handle is pulled out and gear the car down with engine compression.

To operate the OD, push the handle in to freewheel, get the car up to about 30 mph in high, turn on power through the switch, and release the accelerator. If working, it should momentarily free wheel (split second) and you will feel the engine compression slowing down the car when the OD drops in.

There are operating manuals to download on the 'net. Someone will be along to give you a link.
 
Oh it's a Borg Warner overdrive unit ,how numb of me. Yes there is info on it on the internet including operation, care and ratios. If I am reading right it turns a 4:11 differential into a 2.87. Hey I can hardly wait to get this baby on the road! Thanks for the comments.
 
Does it look anything like this one? DD

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Yes Coopman that's the unit.Good pictures! Thanks!I see yours is mounted closer to the rear axle. What car is that in? What does it do for your driving , rpm's and speed? Do you use 90 weight oil? What speeds do you shift at?
 
B-nut said:
Oh it's a Borg Warner overdrive unit ,how numb of me. Yes there is info on it on the internet including operation, care and ratios. If I am reading right it turns a 4:11 differential into a 2.87. Hey I can hardly wait to get this baby on the road! Thanks for the comments.
Click to expand...

Yup you got it, the overdrive ratio is 0.7:1 so your 4.11:1 will now act like 2.87:1 in overdrive.
Martin.
 
One thing the instructions above don't say..."Never attempt to move the lever for the overdrive in or out while the car is in motion, always engage and disengage the mechanism while the vehicle is stopped". If you attempt to change the mechanical engagement while in motion you could seriously damage the overdrive mechanism.

The electric switch can be turned on and off while driving to disengage the solenoid/overdrive, this is useful when attempting to climb a grade.

Others may chime in here.
 
Thanks for all the responses guys! Yes Californiaborn good advice from you who have operated one of these Borg Warners is extra helpful. Is there really something magic about shifting best at 28 mph?
 
B-nut said:
Thanks for all the responses guys! Yes Californiaborn good advice from you who have operated one of these Borg Warners is extra helpful. Is there really something magic about shifting best at 28 mph?
Click to expand...

Yes it's magical, but the reason is a secret.
Martin.
 
The "magic" is that 28 mph is the number that the governor was designed to ground the relay so the solenoid could engage the OD. If the OP has a switch, the magic goes away.

On the comment about only operating the OD handle when stopped: While I haven't looked for the Borg Warner operating instructions, It is entirely safe to operate the handle while driving. The transmission must be out of OD, and enough gas given the engine to propel the car (not coasting or decelerating). Then the handle can be shifted. If the car is in OD, hit the passing gear and pull the handle while the accelerator is down.
 
Does anyone show how the input (main) and output shafts are connected to the torque tube? All this stuff about the operation and wiring. How about the actual installation? I have an R10 and I have no idea how to marry the shafts??? Please help.

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Vcoopman .... those are photos of my BW unit in my '47 which I posted back then. As noted, I was in touch with Llyod Young several years ago and he did say to filler-up with straight GL-4 140w gear oil, which I do using Sta-Lube.

It uses a 30 amp fuse and relay on the firewall. I have the dash pull/push handle and toggle switch (only). You can leave the switch "on" all the time. As long as you are stepping on the gas, you can engage the OD while in forward motion, then let off on the gas and it engages. Best to disengage handle while at a stop. Do not use in first gear - engine has to much torque and can cause long term damage.

I am running 15 inch Coker's.

Lloyd believes these are CA dealer installed kits of the day.
 
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35joe .... Llyod Young who did many OD installations over the years is now about age 84. I don't know if he's still working. He had a full machine shop and the knowledge and experience to make custom shafts and housings. Phone him. He'll help you if he can. Not many of these fellows around anymore.

PS: Your unit looks shorter than my BW R10 (?)
 
Those instructions are a bit vague on operation for what to do and what not. In order to use reverse gear, the unit has to be shifted out of overdrive. If you park the car, it is best to shift it out of OD or the car can roll easily on hills. The clutch in disable switch should allow for a "moving" out shift of OD but shifting it back in may be a different story.

The original R10 electric overdrives had safety features for a good reason. A lot of folks do away with these features when modifying drive trains for these ODs and it can cause breakages if a person doesn't know the operational theory behind these units.
 
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