The transfer case is a major drivetrain component. Its job is to transfer power to the wheels, both front and rear or just one of them. In most modern vehicles, the driver can switch between the drive modes with a button and switch. If you are having trouble with the four-wheel drive not operating Tri City Auto Repair can help. We have the right electronics, electrical diagrams, and repair procedures. It's also recommended to change the fluid regularly to maintain good working condition.