Chrysler laser 1990 Technical Information Manual page 235

MANUAL TRANSAXLE <4WD> - General Information
When driving on rough roads
In case either a front or rear wheel starts spinning on a slippery
or muddy road or when the vehicle is stuck in mud and one tire
spins, the drive power will be decreased by differential action.
However, as this also causes a sharp increase of speed
difference of the viscous coupling, a large differential limiting
torque is now applied, with more power transmitted to the tires
that are not spinning so that the vehicle can drive through
out of mud.
or