Are positrac, limited slip, etc, pretty much just what different brands call their products (Eaton VS GM for example)? A friend said posi-trac functions differently than limited slip but I thought they were all (like a Richmand Locker or Powertrax or something) just basically a slip-and-grip mechanism. I'm guessing spools are much different though. Thanks.

eaton is what GM used to use.

Moroso, is an Eaton posi with heavy duty springs.

Eaton is the best IMO, it uses clutches.

basically a posi is a limited slip.


Spools lock both axles.

Auburn posi uses cones, they wear out and get dust everywhere.

A locker works as such:

this is directly off the Eaton Automotive website:

"We'll start by pointing out that the Locker is a speed sensitive design. That is, it reacts to wheel slip by sensing when one wheel is spinning substantially faster than the other.

So, when you're cruising along on clean dry pavement, the locker operates like any regular open differential.

But, as soon as wheel slip happens, going forward or reverse, the locker immediately kicks in. Here's how.

The differential is set up with a flyweight governor that responds to differences in wheel speeds, and disc packs that are mounted between the side gear and the case.

Whenever one wheel is spinning substantially faster than the other, the governor spins rapidly, causing the flyweight to open. That flyweight then catches on a latching bracket and the lockup process begins.

During lockup, a self-energized clutch system causes a cam plate to ramp against a side gear. This ramping action compresses those disc packs mentioned earlier. The ramping continues until both axles - and therefore both wheels - are spinning at the same speed. This is full lock, and it prevents any further wheel slip. (Note: Axle lockup can only occur at speeds below 20 mph.)

The entire lockup process takes about a split second, and is virtually unnoticeable by the average driver. When both wheels regain traction, unlocking occurs and things go back to normal." - EA