Posi-Traction is a fancy trademarked(GM) name for a limited slip differential. You can get limited slip action by putting heavier oil in the diffs.

I think you are asking about locking the rear axle. Where both axle shafts are essentially locked together. They call them diff lockers, but they are actually like mini'spools for 1:1 cars. A rear differential locker has a locking and unlocking action, where these are always locked, or "spooled" together.


As far as the Kyosho gears, I really know nothing about it. I was just repeating something that I heard at the LHS. This is my first Savage and it came with the four gear setup, so all I've done is rebuilt it back to factory a couple of times.