Inter-axle differential lock
The inter-axle differential lock is used on vehicles with tandem rear axles. Differential lock is controlled by a lever or push-pull control valve on the instrument panel.
This feature can be in only two positions—lock or unlock— as indicated.
Periodically, the valve should be operated to make sure it moves freely; normally the valve should be kept in the unlock position.
Use the lock position only when you approach conditions where one or both wheels of an axle may slip. The valve locks the differential and causes it to act as a “through drive,” transmitting power equally to both axles. Avoid unnecessary use of differential lock since it will result in tire wear and axle strain.
Caution: You should not activate the differential lock when the wheels are actually spinning.
Note: Proper operating instructions vary from manufacturer to manufacturer. Refer to your owner’s manual for further instructions.