Which Is Best, And Most Durable Thanks

 

that depends on what you want to do with it.daily driver, race car/truck, pulling truck, off road truck..... also what truck are you looking to put it in?

a spool will keep both sides locked together all the time. when you turn the inside wheel will be trying to spin faster than it needs to causing it to spin. so if you drive it on the road much i wouldnt go that route.

a locker and a posi in my mind are based on the same concept, a locker requires you to lock in the rear end manually either electric or air. and a posi does it automatically when a certain amount of force is applied. i'm sure someone has better knowledge than i do on the subject. that being said i'd go with a locker if i were to build one the way i wanted to.

 

ARB air lockers are on my wish list!

 

Also many "posi's" are anything but. Powerlok, IMO, is the only truly effective all the time posi... most posi's are posures when the going gets tough...

 

your a little off with you response about lockers there is alot more to them then what you think. There are basically 2 versions of lockers, a selectable (like an ARB), and a automatic (like a detroit). A selectable works like you described above, but a automatic locker works when the torque is applied to the ring gear. The cross pin in the pinion ramps up and spreads the case apart to lock the "cogs" together that the axles are attached to. So when no power is applied (either accell or decell) the dif acts like a standard open dif.

There is a huge difference in a posi and a auto locker, a posi always will allow some slippage and some are worse then others. A auto locker will only unlock when it's free wheeling (coasting) or something breaks. The down side to a auto locker is pavement handling, they are very unpredicatable when they are going to engage or release when your driving into and out of corners. My jeep has a detroit and I have to correct the steering wheel more then 1/4 turn when the locker engages and disengages during a sweeping higher speed corner. Also a auto locker has a certain amount of ring gear rotation before it engages or disengauges, it's like driving a car with a VERY loose ring and pinion set up (lots of back lash).