The front differential is an "open" differential, not limited slip or locker-type. You really want it to be that way. Otherwise, things get kinda' "squirrely", especially in turns, and even more-so on ice.

The idea of "locking" comes from the fact that you "lock" the front drive axles to the front drive hubs with the front "hub locks".

What you call "hubs" are actually "hub locks". They are the things you turn to lock.

The "hubs" are what the front tires and brake rotors bolt onto, and which contain the front wheel bearings.