overdive-instructions and help needed

[mll1446]

I have a 31 model a with overdive it is a borg warner r10

previous owner had no information about it.

has a cable to pull in and out and a lever on the floor near transmission

there are no solenoids on this unit at all or any power switches to turn on

how can I check if this unit is operational?
or how do I even activate the overdrive to see if it works?

[1931 flamingo]

Picture of the inside controls and the unit underneath the car would be a big help.
Paul in CT

[CarlG]

Most likely:
The pull-push cable is to lock the OD out. Typically, pull to lock out, push to operate.
The lever on the floor is to shift in and out of OD.

But like Paul said, pictures of both top and bottom will help confirm this.

[mll1446]

I just posted pics

[mll1446]

I appreciate replies so far but what is the process once cable pushed in and lever at trans pushed forward , then what? how do I operate

[P.S.]

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Difficult to tell by that picture, but it appears as though the engage solenoid was replaced with some sort of pushrod operated kludge.

[CarlG]

Originally Posted by mll1446

I appreciate replies so far but what is the process once cable pushed in and lever at trans pushed forward , then what? how do I operate

Based on operating one with a solenoid (and since like PS said, that obviously has been replaced with a mechanical lever) you would shift the lever, then let up on the gas and it should drop into OD. As far as down-shifting, not sure how that would work, but I would assume (hate that word) that it would work pretty similar.

It's been 50 years since I messed with the BW OD, so take it for what it's worth, from an old man with somewhat of a sketchy memory.

And, of course, it's pretty hard to test things out without an engine.

[tbirdtbird]

need better pix

[Keith True]

The cable is the lockout,and the rod setup is to shift it.I had the same setup,but instead of the rod they used another cable.I didn't much care for the cable shift,although the unit worked well.That square tube sticking out of the side with the rod hooked to it is a part made up to replace the solonoid.It looks to be made by the same guy that made mine up.It was a real simple,well made up conversion.I would just run up to speed,throw the clutch and shift it.I just didn't like the slow action of the cable setup.If I had kept the unit I would have made up a rod and lever setup like yours.It was just too high of an overdrive for my use.I used it in my truck the last time I put it together,rode around with it some,put it up on the lift and took it out.I never use any fast roads,the 33% over was too much for me.23% like in the Mitchell is fine though.

[mll1446]

So Keith take it up to 35 push cable in. Hold clutch in and push rod at trans in

[TerryH]

From what I have heard you do not want to shift it into reverse while in OD....can cause serious damage. And Keith, I believe the Mitchell OD is 26%, which is about perfect for normal Model A use.

[Brother Hesekiel]

I have a Borg-Warner overdrive also. The basic mechanical lever puts the overdrive in or out of the driveline; the electric switch with solenoid, which is NEEDED, will engage it. NEVER have it engaged when driving backward. With the overdrive in the driveline, your car won't drive backward; with the solenoid engaged, it will destroy the overdrive.

Here's the best descriptions I've found after a long search. Read them both -- twice -- before you do anything else.

http://www.fordification.com/tech/overdrive.htm

http://www.ocmafc.org/techarticles/T...0Overdrive.pdf

[mll1446]

what if OD has no solenoids or electrical pieces it appears all manual

[Tom Endy]

Someone has fabricated a mechanical device to replace the solenoid. The original solenoid when actuated electrically moves a pall mechanically inside the overdrive housing to engage the sun gear. The pull cable does not initiate the overdrive, it only releases the direct drive and engages an over run clutch at the output of the overdrive. An over run clutch will only operate in one direction. This is the reason you cannot back up when the pull cable is engaged. You will not do any damage to the overdrive, you just won't go anywhere when you let the clutch out. This is also the cause of free-wheeling.

If you engage the sun gear with the mechanical device and with the pull cable engaged and attempt to back up you can do damage to the overdrive depending on how aggressive the attempt is. It generally tears out the slots where the pall engages.

The Borg Warner overdrive was developed at a time when the gear shift lever had just been moved from the floor to the steering column. Auto makers did not want to make shifting into a fourth gear difficult, so the edict to the BW people was make it invisible. On a "modern" car the driver only has to operate the pull cable once and the rest is done automatically. When you back up a rod inside the regular transmission pushes the pull cable device out of action. The solenoid engages automatically above 35mph with the use of a centrifugal governor. If you wanted to pass another car you pushed the gas pedal to the floor and it operated a switch to kill power to the solenoid. There was even another switch that killed power to the ignition for a few rev's just as the solenoid pulled in to let the overdrive gears engage. The BW also shared the regular transmission oil volume.

When modified for a Model A it gets complicated and cumbersome to operate. The biggest problem is keeping oil in them. Most cottage industry modification use a Model A grease seal in the output that will allow oil to seep into the banjo and the overdrive can easily self destruct for lack of oil. There is also the problem of backing up, and you will run the battery down if you forget to shut power off to the solenoid when parking the car.

Borg Warner overdrive conversions were the only game in town years ago and there are plenty of them still around. For my money I would invest in a Mitchell overdrive. Simple to operate and a factory warranty stands behind it.

Tom Endy

[mll1446]

thank you