4WD DRIVE TERMS DEFINED
Locking differential: Locks both wheels on the axle, forcing them to turn
together to deliver maximum traction.
Limited-slip differential: Detects slippage in one wheel and sends torque to
the other wheel that is not spinning. Its operation is automatic.
On-the-fly-shifting: This term means that the 4WD can be engaged while
driving the vehicle. A lot of systems require that you stop the vehicle before
engaging the 4WD.
Automatic hubs: Some systems require that you manually “lock in” the
front wheels in order to drive in 4WD because they freewheel when the 4WD
is not engaged. On vehicles equipped with automatic hubs, the only thing you
have to do to “lock in” the front wheels is to flip a switch.