4Matic all-wheel drive system

Content

What is 4Matic all-wheel drive system
The history of the creation of all-wheel drive
How the 4Matic system works
Features of the 4Matic system
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Vehicle handling is one of the most important factors on which road safety depends. Most modern vehicles are equipped with a transmission that transmits torque to one pair of wheels (front or rear wheel drive). But the high power of some powertrains is forcing automakers to produce all-wheel drive modifications. If you transfer torque from a high-performance motor to one axle, slipping of the driving wheels will inevitably occur.

To stabilize the vehicle on the road and make it safer and more reliable in a sporty driving style, it is necessary to distribute torque to all wheels. This increases the stability and control of transport on unstable road surfaces, such as ice, mud or sand.

If you properly distribute the efforts on each wheel, the car is not afraid of even the most severe road conditions with unstable surfaces. To fulfill this vision, automakers have long been developing all sorts of systems that are designed to improve the car's handling in such conditions. An example of this is the differential (in more detail about what it is, it is described in another article). It can be inter-axle or inter-axle.

Among such developments is the 4Matic system, which was created by the specialists of the famous German car brand Mercedes-Benz. Let's consider what is the peculiarity of this development, how it appeared and what kind of device it has.

What is 4Matic all-wheel drive system

As already clear from the introduction, 4Matic is an all-wheel drive system, that is, the torque from the power unit is distributed to all wheels so that, depending on road conditions, each of them becomes the leading one. Not only full-fledged SUVs are equipped with such a system (for more information on what type of car it is, and how it differs from crossovers, read here), but also cars, under the hood of which a powerful internal combustion engine is installed.

The name of the system comes from 4WD (i.e. 4-wheel drive) and autoMATIC (automatic operation of mechanisms). The torque distribution is electronically controlled, but the power transmission itself is of a mechanical type, not an electronic simulation. Today, of all such developments, this system is considered one of the most high-tech and equipped with a wide range of settings.

Consider how this system appeared and developed, and then what is included in its structure.

The history of the creation of all-wheel drive

The very idea of introducing all-wheel drive into wheeled vehicles is not new. The first full-wheel drive car is the 60 Dutch Spyker 80 / 1903HP sports car. At that time, it was a heavy-duty car that received decent equipment. In addition to transmitting torque to all wheels, under its hood was an in-line 6-cylinder gasoline power unit, which was a great rarity. The braking system slowed down the rotation of all wheels, and there were as many as three differentials in the transmission, one of which was center.

After just one year, a whole line of all-wheel drive trucks was created for the needs of the Austrian army, which were presented by Austro-Daimler. These models were later used as a base for armored cars. Closer to the beginning of the twentieth century, all-wheel drive could no longer surprise anyone. And Mercedes-Benz was also actively involved in the development and improvement of this system.

XNUMXst generation

The prerequisites for the emergence of successful modifications of the mechanisms was the presentation of a novelty from the brand, which took place within the framework of the world famous motor show in Frankfurt. The event took place in 1985. But the first generation of all-wheel drive from the German automaker went into production two years later.

The photo below shows a diagram that was installed on a 124 Mercedes-Benz W1984 model:

There was a hard blocking in the rear and center differentials (for details on why you need to block the differential, read separately). An inter-wheel differential was also installed on the front axle, but it was not blocked, since in this case the vehicle's handling deteriorated.

The first series-produced 4Matic system was involved in the transmission of torque only in the event of a spin of the main axle. Disabling all-wheel drive also had an automatic mode - as soon as the anti-lock braking system was triggered, all-wheel drive was also disengaged.

In that development, three modes of operation were available:

100% rear-wheel drive. All torque goes to the rear axle, and the front wheels remain only swivel;
Partial torque transmission. The front wheels are only partially driven. The distribution of forces to the front wheels is 35 percent, and to the rear - 65 percent. In this mode, the rear wheels are still the main ones, and the front ones only help stabilize the car or get out onto a better section of the road;
50 percent torque split. In this mode, all wheels receive the same percentage of torque to the same extent. Also, this option made it possible to disable the rear axle differential lock.

This modification of the all-wheel drive was used in production cars of the auto brand until 1997.

XNUMXnd generation

The next evolution of the all-wheel drive transmission from the German manufacturer began to appear in the models of the same E-class - the W210. It could be installed only on those cars that were operated on roads with right-hand traffic, and then only on order. As a basic function, 4Matic was installed in the W163 M-class SUVs. In this case, the four-wheel drive was permanent.

Differential locks received a different algorithm. It was an imitation of an electronic lock, which was activated by the traction control. This system slowed down the rotation of the skid wheel, due to which the torque was partially redistributed to the other wheels.

Starting with this generation of 4Matic, the automaker has completely abandoned rigid differential locks. This generation existed on the market until 2002.

III generation

The third generation 4Matic appeared in 2002, and was present in the following models:

C-class W203;
S-class W220;
E-Class W211.

This system also received an electronic type of differential locks control. These mechanisms, as in the previous generation, were not rigidly blocked. The changes affected the algorithms for simulating the prevention of slipping of driving wheels. This process is controlled by the traction control system and the dynamic stability system.

IV generation

The third generation existed on the market for four years, but its production was not completed. It was just that the buyer could now choose which transmission to equip the car with. In 2006, the 4Matic system received further improvements. It can already be seen in the list of equipment for the S550. The asymmetrical center differential has been replaced. Instead, a planetary gearbox was now used. His work provided a 45/55 percent distribution between the front / rear axles.

The photo shows a diagram of the fourth generation 4Matic all-wheel drive, which was used in the Mercedes-Benz S-Class:

Due to the fact that the mechanisms of modern transport began to receive more and more electronic controllers, the control of the controllability of the driving wheels has become more effective. The system itself was controlled thanks to signals coming from sensors of various systems that ensure the active safety of the machine. The power from the motor was continuously supplied to all wheels.

The advantage of this generation is that it provides an optimal balance between efficient vehicle handling and excellent traction when overcoming rough terrain. Despite the advantages of the system, after seven years of production, its further development followed.

V generation

The fifth generation 4Matic has appeared since 2013, and it could be found in the following models:

CLA45 AMG;
GL500.

The peculiarity of this generation is that it is intended for vehicles with a transverse power unit (in this case, the transmission will turn the front wheels). The modernization affected the design of the actuators, as well as the principle of torque distribution.

In this case, the car is front-wheel drive. Power distribution to all wheels can now be activated by activating the corresponding mode on the control panel.

How the 4Matic system works

The structure of the 4Matic system consists of:

Automatic boxes;
Transfer case, the design of which provides for the presence of a planetary gear (starting from the fourth generation, it is used as an alternative to an asymmetric center differential);
Cardan transmission (for details on what it is, as well as where else it is used in cars, read in another review);
Front cross-axle differential (free, or non-blocking);
Rear cross-axle differential (it is also free).

There are two modifications of the 4Matic all-wheel drive. The first is intended for passenger cars, and the second is installed on SUVs and minibuses. On the market today, there are often cars equipped with the third generation of the 4Matic system. The reason is that this generation is more affordable and has a good balance of maintainability, reliability and efficiency.

Another factor that influenced the popularity of this particular generation is the rise in activity of the German automaker Mercedes. Since 2000, the company has decided to reduce the cost of its products, and, on the contrary, to increase the quality of the models. Thanks to this, the brand gained more admirers and the term “German quality” took root more firmly in the minds of motorists.

Features of the 4Matic system

Similar four-wheel drive systems work with manual transmissions, but 4Matic is installed if the transmission is of an automatic type. The reason for the incompatibility with mechanics is that the distribution of torque is carried out not by the driver, as in most models of all-wheel drive cars of the last century, but by electronics. The presence of an automatic transmission in the transmission of a car is a key condition that determines whether such a system will be installed in the car or not.

Each generation has its own principle of operation. Since the first two generations are extremely rare on the market, we will focus on how the last three generations work.