Differential lock inop

[Rawze]

On most trucks, the diff lock only enforces the drive-shaft to spin from the front diff to the rear diff. Has nothing to do with forcing both tires to spin on the same axle. With it off, only one tire spinning will make you get stuck. with it on, it takes one tire at each of the axles to make you get stuck. They are typically referred to as a "inter-axle" lock.

They do make diff locks that enforce both tires to spin on the same axle, but most highway trucks do not have this option. They are typically referred to as an actual "differential" lock, "double", or Positive traction" lock.