Locking Differential Service
LOCKING DIFFERENTIALDrain the fluid and refill the fluid at the first engine oil change. At subsequent oil changes, inspect the fluid level and add fluid as necessary. Drain the fluid and refill the fluid every 25 000 km (15,000 miles) if the vehicle is performing either of the following actions:
^ Driving in dusty areas.
^ Towing a trailer.
NOTE: Heavy-duty or off-road use may require more frequent lubrication.