I found this cool and rare brochure for the ill-fated Sierra Dana 20 overdrive on eBay. It’s printed on 8.5″x11″ paper, so the marketing budget must have been tight (as I understand it, working capital was an early issue, which played a part in the demise of the company). A few years ago there was a post of an article that also highlighted this rare overdrive.
The following instructions and schematics were tucked inside the brochure above:
never seen or heard of this one ( repairing collecting driving crashing willys jeeps since the 60’s ) – I have a rancho borg warner r-10 overdrive for a dana 20 – i’m going to use it on a 1970 jeepster commando , 225 v-6 , t-14 , mod 20 , you have to shorten the rear drive shaft – cant remember the axle ratios ..
From what I remember about the unit, they had a lubrication problem
I probably have that brochure, might have some info in the old 4WD magazines.
Here is and article from FOURWHEELER that mentions the Sierra and some other neat information.
https://www.fourwheeler.com/how-to/transmission-drivetrain/154-0611-jeep-standards-capabilities-old-school/
Thanks Blaine … Aahhh .. I had seen that article, because that’s where I learned about the lack of capital for Sierra!