My gut told me that wasn't any 1978 part when I saw the 3.56. I believe that ratio was only available very early on in 9" production. That, and the WAR case was also only used very early on... IIRC both of these parts were discontinued somewhere around 1962. Find another chunk to worry with.
Here's what Wikipedia says: Factory names In the 1950s and 1960s many manufacturers began to apply brand names to their LSD units. While Packard pioneered the LSD under the brand name "Twin Traction" in 1956, the most famous of these in the USA was Chevrolet's "Positraction". Since then, Positraction (often shortened to "positrac" or merely "posi") has become a genericized trademark for LSDs in the USA. Other factory names for LSDs include: Alfa Romeo: Q2 American Motors: Twin-Grip Buick: Positive Traction Chevrolet/GMC trucks (after 1973): Gov-Lock Chrysler: Sure Grip Dana Corporation:Trak-Lok or Powr-Lok Ferrari: E-Diff Fiat: Viscodrive Ford: Equa-Lock and Traction-Lok International: Trak-Lok or Powr-Lok Jeep: Trac-Lok (clutch-type mechanical), Tru-Lok (gear-type mechanical), and Vari-Lok (gerotor pump) Oldsmobile: Anti-Spin Pontiac: Safe-T-Track Porsche: PSD (electro-hydraulic mechanical) Saab: Saab XWD eLSD Studebaker-Packard Corporation: Twin Traction TVR: Hydratrak
Ditto, someone needs to take a chill pill.he be nitpickin over nothing. A GM "posi" works exactly like a Ford Traction-loc. :deadhorse
I had a WAR case diff I pulled from a 66 Stang, that obviously was installed in that car by a previous owner. It too acted the same as you describe. I'm not 100% sure, but I think it was either some form of early "locker" type diff(not a clutch type) or a "4 pinion" diferential. This one was a 3.70 ratio. It's definatley worth what you paid for it, but it's not a 1978 part, more like a 1958 part.
Ya know... it's not that big of a deal. I put posi in quotes because I knew it wasn't correct, but the conversation was using that word, and I knew what he meant... and that is all that really matters. The one that folks should be concerned about is confusing a 'locker' with a limited slip diff... which is very easy when they are called things like Traction Lock and Equa-Lock. Limited slip and 'lockers' are totally different animals. Limited slip transfers power back and forth between wheels through mechanisms devised to compensate for traction loss. A locker is pretty dumb in that it sends both wheels full power at all times. The only difference between a spool and a locker is that the locker has the ability to spin one wheel slower than the other when making turns and such. Trivia: Equa-Lock Ford diff is the earlier version of LS, and only has one pinion with only one pair of spider gears. The Traction-Lock was the beefed up version with dual pinions and double sets of spider gears. Both versions use friction clutches to alternate power back and forth between wheels.
i know that posi is not ford's saying but u know what i'm talking about RIGHT i'm 25 and everyone from my generation calls it POSI unless you are selling me a rear end i dont care what type of unit it has
Yes I know what you are talking about. It's like calling a refrigerator a Frigidaire or sofa a Davenport. I'm not picking on you or anybody else, I'm only saying this so people will know a little bit of facts about the company that made their Maverick/Comet. How many times has someone corrected a post about having a Maverick that came with a Boss 302 or a 9" from the factory? But if someone says a Ford positive traction rearend wasn't called a Posi ™ then it hurts their feelings and they get offensive and wants me to take a chill pill. :Handshake
