A transfer case is found on all 4-wheel drive vehicles. Acting like a transmission between the front and rear differentials, it selects the proper high/low gear ratio distributing torque to the wheels depending on the driving situation.
To ensure proper lubrication and sufficient coolant properties, check your owner’s manual for the minimum required service interval for your 4-wheel drive vehicle.
For Land Rover Discovery’s we recommend adding a change of your Transfer case oil to your 45k, 75k and 105k service