Transfer case: what it is, how it works

The transfer case (transfer case) is the main part of a four-wheel drive vehicle. It plays a big role when driving in hard-to-reach places and generally improves the vehicle’s handling. If the transfer box and other major components of the car are badly damaged, it is worth scrapping it. This way you will save nerves and time, as well as get good money:

Transfer case operating modes

The transfer box (transfer case) is the main part of a four-wheel drive car. It is used to distribute torque to the wheels at the same time. It allows turning both axles of the car into drive axles. It plays a big role when driving in hard-to-reach places and in general increases the drivability of the car.

What a transfer case in a car is for

The transfer case is installed on almost all four-wheel drive cars. It is responsible for both transmitting torque to the 4 wheels and allows you to change the power of the transmitted torque to each axle. AmongĀ 

other things, it has the following effect:

Affects the stability of the vehicle at low speeds and the performance of the engine at high power;

Improves the traction characteristics of the car if there is another box in the transfer case;

Increases torque when the vehicle is lifted, goes through heavy sections of road, or drives off-road.

Types of transfer cases

There are only four types of transfer boxes:


Simple (not disconnectable);



The manual types require a lever that is close to the gearbox. It is difficult to operate.

The biggest advantage of simple units is a lot of wear and tear. These mechanisms are easy to use and constantly active. Predominantly, they are installed on cars that are designed to drive at high speeds.

The automatic transfer case starts from the electronic system. Perfectly controls the car on the road with any surface, but has one significant disadvantage: the mechanism can fail due to exposure to moisture.

Semi-automatic mechanisms lend themselves to control by a rotary device on the dashboard. The biggest advantage is the ease of operation, the only disadvantage is the driver’s attention, which is switched from the road to the dashboard.

How the transfer case works

The transfer case is located approximately behind the gearbox. There are four types of them, but the principle of operation is identical in all of them:

Torque is transmitted from the transmission to the transfer case drive shaft;

From the drive shaft, power is transmitted to the axle differential;

The differential divides the torque between the axles of the car;

Distributed torque is transmitted to each axle.

The inter-axle differential is very important and affects the traction and speed of the shafts in the car.

The most reliable type of transfer case is the pinion type, which can be replaced by another type. It has 4 shafts that have gears that help the transfer case parts interact with each other.

The transfer case can be controlled by the dashboard. On some cars, it works in automatic mode.

On average, there are several transfer case modes:

Both axles are active, the automatic inter-axle differential unit;

Rear axle activity;

Reduced transfer gear. Both axles are active, differential is locked.


Leave a Reply

Your email address will not be published. Required fields are marked *