Posi traction is what GM calls their LSD. A LSD uses clutch discs to transfer a very limited amount of torque from a spinning tire to a non spinning tire. A locker uses gears and pins to lock the differential and cause both tires to spin. A Detroit Tru Trac differential is a gear driven torque biasing traction enhancing differential that uses gears to transfer up to 40% of the available torque to the tire with the most traction.

 

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