Rare overdrive question

Hi Guys, I have a Borg Warner overdrive that bolts to the back of a Dana 20 transfer case. It came off a '70 Commando. Is anyone here familiar with the unit and exactly how it works? I want to set it up and get it working but I don't want to damage it by accident. This isn't the Saturn unit that goes behind a D18.

 

Cool, second one I've heard of . First one was in a 71.

 

The BW unit itself is not that rare, as it was used by many of the manufacturers in the 60s and 70s. It was available behind the Dana 20 in Jeepsters, Broncos, and Scouts. The part that may be hard to find, "rare", would probably be the adapters to the Dana 20.

There is some info here at the Classic Trucks website and rebuild info here on the same site.

The Studebaker site has a manual and at this Studebaker site

Some more wiring info can be found at this site.

Some photos and info at a Willys Website.

Lots of good information at these sites. I have a unit, which came from a Jeepster, I am planning to use on a future project.

 

The Studebaker site is the clearest version of the manual yet. I'm not looking for "automatic" operation. It looks like there's the solenoid and the lockout lever. I'm trying to figure out how to operate it simply.

I know they came on jeepsters, not sure about broncos, and I'm fairly positive they didn't come on scouts.

 

Rancho sold the kits for the Jeep, Ford, and IH products using the BW units.

 

Did jeeps come from the factory with them or were they all kits?

 

Here is a low res scan of the Rancho BW OD kit for Dana 20 & Dana 18 equipped vehicles.

 

Thanks Hans!! That's great!


It looks like if I want to use it in a most basic mode, power to the solenoid gets me OD. I'll have engine braking in OD. No power to the OD gets me normal 1:1 and if I want engine braking, I have to yank the lever on the side with a cable. It ALSO looks like there's an interlock between the two so I can't engage both at the same time by mistake.

Does that sound about right? I see there's the govorner that kept it from coming on before 35mph +/- but would it be a problem to leave it engaged all the time? Anyone have an idea how tough these are? I do a little wheeling and would hate to pop it on the trail.

 

Might also contact Herm Tilford also known as hermtheoverdriveguy at
http://www.hermtheoverdriveguy.com/

He was having some of the BW overdrive stuff made and has tons of info on od's used in Jeeps. Nickmil

 

Call or e-mail Herm the Overdrive Guy, someone posted the link earlier. He used to have wiring diagrams on his site, I don’t know where they went but if I can find my copies I’ll post them here for you.
To operate, you have to wire the solenoid to a switch.
When you are going down the highway and want to engage OD, shift the OD “in” at the linkage you mentioned. Use some hand-operated cable, like a choke cable or something.
Once shifted "in" and going over 30 MPH, or where ever the governor is set, let off the gas then step back into it when you feel the OD engage. It’ll do it automatically when the drive line is unloaded by letting off the throttle.
To disengage, press the button wired to the solenoid and let off the throttle. You’ll feel the OD disengage, and then you can shift the OD “out” to lock in 1:1 drive.

 

Well I have to say, Herm hasn't been very helpful. There's something wrong inside related to the overdrive gears. I keep trying to ask intelligent questions, explaining exactly what I observe and what's wrong and I get back short answers. Maybe he doesn't want to sell parts, only a full rebuild?

Has anyone had one apart before? Are there any pitfalls to disassembling it? Are there any other places on the 'net that know about these boxes and have parts?

 

You may want to try the Studebaker or Chevy Truck sites I referenced above. There may be someone who is knowledgeable about those units, if they have a BB like this one. I have not done anything with mine other than research sources for parts and manuals.

You may want to check with Gear Vendors also.

 

you can find them on 40s, 50s, and 60s, 2WD Willys Wagons, Pickups, and Jeepsters.
While they won't bolt up to a 4WD transfer case, you can scavenge some parts off of them.

 

Yes, they’re a PITA. Everything is “Oh Jesus!” clipped together. Getting the outer housing back into place with the linkage line up properly is where I had the biggest problems. Though I’ve read that you have to be careful with the needle bearings in the “free wheeling clutch” because they can scatter across your garage floor when disassembling.
Have you found a manual online yet? I’ve got it saved in a file if you need it. It has full disassembly and reassembly instructions but I won’t waste the bandwidth here if you already have it.