Yup. An LSD (Posi) is locked by default but allows limited slip, a locker is unlocked by default and locks when slip is detected. Semantics maybe, but an important differentiation. Either way is far better than an open differential.

 

Where are you guys buying your ValueTracs? I cant seem to find them anywhere.

 

Ron's machine shop. Look in sponcer sales

 

finally put mine in. so far so good. locks every time.

 

A tru-trac is NOT a locker, it is a limited slip differential ( torsen type )
even Eaton calls it a limited slip (Performance Products | Detroit Truetrac Differential)

A normal auto locking locker on the other hand like a detroit locker will stay unlocked in a rachet type mode until the driveshaft torque is greater than the torque coming from the wheels ( i.e. accelerating vs coasting ) at which point it fully locks into a spool type mode. ( and is really annoying on the highway as accelerating then coasting will cause you to wander )