Borg Warner Speedo Drive Gears

Pilotdave

Pilotdave

Well-known member
Our Fordor has a BW R10 od in it with a completely mechanical system to activate and engage/disengage it. Includes a reverse lockout device. Thus there's a cable to activate it and a Mitchell-like shift lever to engage/disengage it. It's pretty useful even here in New England where the landscape is pretty hilly!

There's one feature that I'm trying to correct: the speedometer cable was never extended to connect to the drive train behind the od - so I can't rely on the speedo when using the od. [I use a cellphone app instead.] I've had an extension cable made and now am on the hunt for a set of gears that connect the speedo drive gear inside the od to the speedo cable. These have a (driven) gear on one end and a square bore on the other end that slides over the speed cable. I've spoken with several guys who either worked on these units or did the conversions for Model A use - no one knows a source for these gears.

Any ideas out there? Thanks so much.
 
Dan - thanks - I will give Mac a call.

I've spoken with several people in California - the aforementioned fellows who have worked on and/or modified BW units. They have been helpful but the drive gears remain elusive!
 
Years ago, I had an inline gear reduction box made that was installed in the speedo cable. Had to give the guy two odometer readings one from the model a one from the modern car that followed me, drove about 10 miles. The conversion ratio was write on!
 
What I described was simply a gear change box that was installed in the speedo cable.
It has nothing to do with operating the O/D. The B/W O/D has a speedo port at the end of the O/D.
 
I have a "Ratio Adapter" in my '55 Ranchwagon to get the speedometer to read correctly. It is on the output shaft of the Gear Vendor O/D.

545673
 

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Yup, bought a couple of those Stewart/Warner ratio adapters at Hershey some years ago. Fortunately I had just the one I needed to correct the reading from my Laycock (Volvo) overdrive. Great devices to have.
 
The BW overdrives measured rpm off the output shaft in line with the governor drive. The only ratio that affects it from there is the rear axle ring & pinion ratio as far as drive system components are concerned. The rear wheel diameter has an affect as well. If a person uses the BW speedo drive then a ratio correcter adapter box would be the best way to get some speed indicator accuracy.

When I needed tachometer drive cables for the old Bell 47 helicopters, there is an outfit in San Antonio by the name of SX Callahan that had the equipment to fabricate any length of cable a person needed. They had a number of different drive types that could be swaged onto a core plus the equipment to square off the ends. Speedometer shops used to do this stuff. SX Callahan is still around but I don't know if they still make up tach and speedometer cables or not. Universal cable kits are also available. This link is to an outfit that has a lot of this type of stuff.

https://mrspeedometer.com/collections/cable-shaft-and-core
 
Great to see so many comments on this thread! Thanks.

I am looking for a part that inserts into the OD and into the speedo cable fitting. The OD end is a driven gear; the speedo cable fitting end has a square bore that engages the square speedo cable itself. Would love to find a source for these!
 
Not quite! Mine is labeled R10B-1U. And the speedo port is above and behind the model #. Yours perhaps is integrated with the transmission? If so, that's another difference - mine is separated from the transmission and mounted in the driveshaft about 6" in front of the differential.
 
So is the end of this cable part of what you re looking for?
 

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That conical shaped drive end is a give away for Borg Warner ODs. The gear fits into the end of that cone. Ford generally used the 3.9:1 ratio on Ford and Mercury rear axles with overdrive. My 51 Mercury cars use the 20 tooth gear with a 3.91:1 rear axle ratio. This link is what they look like but it is for a GM set up.
https://www.ebay.com/itm/281494413121
 
Bob/Rotorwrench - it's complicated! Please bear with me as I explain.....

I started out looking for the cable assembly including the conical fitting and the gears. I had a cable assembly made at Bob's Speedometer Service in Michigan, but they have no gears. I'm not sure that the conical fitting is correct - I loaned them a cable assembly that belongs to a friend so that they could try to match the fitting. They got close, but the diameter of the bore into which the gear fits is smaller than my friend's. Now I'm trying to find gears like the one in rotorwrench's eBay link, hoping they will fit! All this is made more complicated because I have no idea what make/model the OD unit was originally installed in!

One fellow I spoke with told me that I need to know whether the teeth on the OD drive gear are left or right-hand. Or perhaps straight. I've also been told that there is no way to identify which car male/model my OD was installed in without taking the unit apart.

I haven't yet removed the plug that's in the port in the OD to inspect the drive gear because I'm concerned that I may damage the plug when removing it.

I'm hoping that I can locate a source for driven gears that will fit the fitting on the cable assembly - preferably one that has variety of gears that were used in different make/model applications. eBay may be the place to go, but it'd be great if there's someone out there who has a variety of gear designs.

Thanks, both of you, for your suggestions! Any further ideas would be greatly appreciated.
 
I went through a couple on my interchange books and found a little info.
R10B-1 47-49 Studebaker, 46-50 Kaiser Frazer.
R10B-1H 51-55 Kaiser, 53-54 Hudson Jet.
R10B-1E 51 Frazer, 52-54 Hudson.
 
Thanks, Bob. Nice to know that there's some documentation! Can you explain what an "interchange book" is? I'm wondering if there's another version/edition that include R10B-1U..........
 
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