How to drive an automatic transmission, how to do it correctly

Our post today will be devoted to such a pressing topic as the automatic transmission, the meaning of the letters, it is especially relevant for those who are changing from a manual transmission to an automatic transmission. Such a driver sees the speed lever with completely unfamiliar values ​​and numbers. And the first feeling he will have is that nothing is clear, the native mechanics are closer to the heart and understandable. But in fact, everything is very simple, literally after a week of driving an automatic transmission, the newly-minted “automatic driver”, so to speak, will, without any difficulty, set the car’s speed control knob to the position he needs, without even thinking about it.

Here, for example, are ordinary photos of some types of automatic transmissions in automobile gearboxes. For many mechanical enthusiasts, these symbols do not mean anything, but only confuse them more and distance them from the automatic transmission.

Therefore, let's try to dispel the fog of doubt and ignorance by explaining the meaning of each symbol on the automatic transmission:

1. R – translated in English as Parking, parking or parking. The car is switched to this mode only after a complete stop. If you are standing on a hill, it is recommended to first put the car on the handbrake and only then move the lever to the Parking position, after which you can leave the car and go about your business
2. R - literally Reverse, back, back - that is, normal reverse gear, engage it when there is a need to drive in reverse
3. N - translated as Neutral, that is, neutral, neutral speed, it is mainly used for towing a car, usually when standing in a traffic jam, it is recommended to hold the brake pedal without moving the car to the neutral position - since this is not a manual transmission, but nevertheless, many automatic transmission owners when parking, especially in traffic jams, move the lever to position N , because you must admit that keeping your foot on the pedal for 20-30 minutes is not at all comfortable
4. D or A - you can find both of these designations Drive or Automate, which is essentially the same thing, that is, you switch to this position when you need to drive, squeeze the brake, put the speed lever in position D or A and simply press the gas pedal, smoothly releasing the pedal brakes and all movement has begun, now there is no need to switch the handle, just regulate the speed of your movement by pressing the gas pedal in your car with your foot
5. L or B (l, 1, 1L) - some types of automatic transmissions are equipped with additional functions (Low or Bottom) which can literally be translated as slow or first gear. Typically used on ice, very steep descents or uphills, or for engine braking.
6. B or simply Block often means differential locking, usually on jeeps or all-wheel drive cars, in which cases it is better to read the manual for your car model
7. 2 or 2L, 3 or D3, 4 or D4 - means limiting the speed switching by the gearbox, that is, set it to 2 - it means the gearbox will not shift above second gear no matter how hard you press on the gas, set it to mode 3 - the box will not shift above third gear will switch no matter what you do with the accelerator pedal, the same will happen in 4 - the shift will not occur above the fourth speed, for example, you have 6 steps in the box, you set it to mode 4 - this means the car itself will shift from 1st to 4th gear, auto to 5th -and 6 will no longer switch

Regular machine

It is a hydromechanical gearbox. Despite the fact that the design appeared more than half a century ago, it is still very relevant. Of course, its device has been significantly improved to this day. Now such boxes have six gears. If we talk about cars from the 80s and 90s, they had a four-speed automatic transmission.

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The design of this gearbox includes:

• Manual Transmission.
• Torque converter or “donut”.
• Control system.

If such a transmission is equipped with a front-wheel drive car, it also includes a main gear and a differential. One of the most important parts in an automatic transmission is the torque converter. It consists of several parts. These are pump, turbine and reactor wheels. Thanks to them, torque is smoothly transferred from the internal combustion engine to the manual transmission.

The automatic transmission also includes a clutch (freewheel and locking). These elements, together with the turbine wheels, are closed in a round metal case, shaped like a donut. There is a working ATP fluid inside the torque converter. A pump wheel is connected to the crankshaft. And on the gearbox side there is a turbine. A reactor wheel is also located between these two elements.

The principle of operation of the automatic transmission

Now let's look at how an automatic transmission works. If you try to disassemble a machine and look inside, you will see a wide variety of different mechanisms and devices in a relatively small space.

Sectional view of automatic transmission

The principle of operation of a planetary gear set with gearboxes is to create gear ratios. Essentially, every other component in the transmission system is designed to help the planetary gear set perform this function.

The torque converter itself includes several components:

• inlet turbine;
• turbine output;
• stator.

Often the stator is braked to the unit housing, but sometimes the brake of this turbine is activated by a moving clutch for maximum efficient operation of the torque converter in any engine speed range.

The moving clutches themselves, while the vehicle is moving, change gears by connecting or disconnecting the components of the “automatic machine”. In particular, we are talking here about the input and output shafts and planetary gear components. Visually, the clutch is something between a clutch and a synchronizer in traditional “mechanics”.

This element consists of a drum and a hub, between which there is a package of ring-shaped moving disks. The part of the disks that connects to the drum is made of metal, and the part that connects to the hub teeth is made of plastic.

Sectional view of the automatic transmission torque converter

The principle of operation of the clutch is to compress the package of these ring-shaped disks with a hydraulic piston, which is located directly in the drum. The transmission fluid approaches the cylinder through pipes located in the drum, shafts and body of the “automatic machine”.

In turn, the principle of operation of the overrunning clutch is to slip in one direction and jam and transmit torque in the other. As a rule, such a coupling consists of several rings - external and internal, as well as a device with rollers located between them. Overrunning mechanisms are used to reduce the level of shock in moving clutches when changing gears.

The transmission of torque itself occurs when the engine speed increases after switching, as a result of which one of the parts of the planetary gear rotates in the opposite direction. Accordingly, it jams in the overrunning clutch.

Automatic transmission torque converter disassembled

The gearbox control unit consists of devices that direct the flow of transmission fluid to the pistons of the brake bands and moving clutches. The positions of these devices can be set either manually, using the gearshift lever, or in automatic mode. The automation itself in such gearboxes can be either electronic or hydraulic:

• hydraulic automation. The principle of its operation is to use ATF (transmission oil) pressure from a central regulator, which is connected to the gearbox output pulley. Also, this type of control uses the ATF pressure from the pressed gas pedal, which gives it information about the speed of the vehicle and the position of the gas pedal;
• electronic automation. This type of control uses solenoids, the principle of which is to switch spool valves. The wires from the solenoids are connected to the control device. Thanks to the “brains,” movement occurs based on data about the position of the gas pedal and the overall speed of the car.

Automatic modes

Automatic transmission lever
The automatic transmission does not have actual speeds for switching, but its design provides operating modes, which we will consider below:

• "N" - neutral speed. Typically used by vehicle owners when towing or when stopped for short periods of time;
• "D" - forward movement position. At this moment, all stages are used in the automatic transmission;
• "R" - reverse movement. This gear is needed to move the car in reverse. Under no circumstances should this position be activated unless the vehicle has completely stopped;
• “L” - low speed position, often used for coasting;
• “P” is a position that is activated on the automatic transmission during parking to lock the drive wheels. It should be noted here that this “automatic” position has nothing to do with the handbrake.

Mode “P” of the automatic transmission
These were the main modes of the automatic transmission. There are also additional ones that are found on many cars:

• “O/D” is a driving position that provides the ability to switch to a higher gear automatically. This mode is usually activated while driving outside the city at high speed;

• “D3” is the gearbox position in which the automatic transmission can use only one of the first three gears or disable higher speeds. In this position it is convenient to drive in urban areas and in traffic jams;
• “S” — automatic transmission position when driving at low speeds;
• “L” is an automatic transmission mode in which only first gear operates.

How it works?

What is the operating principle of this type of automatic transmission? The classic machine operates in a closed cycle. As we said earlier, there is ATP liquid inside. This is a kind of gear oil. But, unlike a manual gearbox, it not only performs a lubricating function, but also transmits torque. What is the operating principle of the automatic transmission fluid coupling? Under pressure, this liquid enters the turbine wheel (from the pump wheel), and then enters the reactor wheel. Since it has blades of a special shape, the speed of fluid flow as the element rotates begins to gradually increase. Thus, ATP oil drives the turbine wheel.

Peak torque in the transmission is generated when the vehicle is moving away. As the speed of the machine increases, the lock-up clutch is activated. The latter serves to rigidly block the automatic transmission “donut” in certain operating modes of the internal combustion engine. This usually happens when the speed of rotation of the shafts coincides. Thus, torque is transmitted to the gearbox directly, without “grinding in” or changing the gear ratio. By the way, modern automatic transmissions use a slipper clutch. It is capable of eliminating complete blocking of the torque converter in certain modes. This contributes to a smooth acceleration and fuel economy.

What do the letters on the automatic transmission mean or the meaning of the buttons on the automatic transmission lever?

Such buttons can be either on the shift knob itself or near it:

• OD - or known as (Over Drive) is similar to mode 3 or D3 - made so that when driving, for example, at a speed of 60-80 km/h, your transmission constantly clicks, switching from 3 to 4 and vice versa from 4 to 3 gear, so that this did not happen, turn on the OD , in fact, this mode automatically activates mode 3, which means you will move in 3rd gear
• M - translated as Manual, that is, manual control, you can choose when to turn on and what speed to turn on in your car, this is usually done with the + and - buttons either on the speed lever or on the steering wheel or with the paddles behind the steering wheel or under the steering wheel
• S – or otherwise (Sport) not all gearboxes are equipped with it, sport mode implies more active movement and speed gain, which, of course, will affect fuel consumption
• W or Snow sometimes also draw a snowflake - which means (Winter) in our winter mode, puts the box into a very smooth starting mode so as not to shovel snow under you and sit on your belly
• E – can be translated (Economic) as economical, the car will not be too playful, but fuel will be consumed significantly less
• KickDown - or “gas to the floor”, many have probably heard this expression, it exists so that when the gas pedal is pressed sharply and all the way to the floor, the box switches to one or two gears lower for a very quick increase in speed, used when overtaking or, when you don't have time to stop overtaking

Manual transmission in automatic transmission

As such, there is no mechanics familiar to all car enthusiasts in this transmission. The role of a mechanical gearbox is performed by a planetary gearbox. It can be designed for a different number of stages - from four to eight. But still, the most common options are six-speed automatic transmissions. In rare cases, you can find a nine-speed automatic (for example, on the Range Rover Evog).

How does the automatic transmission work? This unit in the transmission is a set of several sequential speeds. All of them are combined into a planetary series. The planetary gearbox includes the following components:

• Sun and ring gear.
• Driven.
• Satellites.

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If you delve into the design and operating principle of the automatic transmission torque converter in detail, you will notice that the change in torque is carried out using the carrier, as well as the ring and sun gears. When the second mechanism is blocked, the gear ratio increases. The blocking itself is performed by the operation of the clutches. They hold the planetary gear parts by connecting them to the box body. Depending on the make of the car, the design uses a multi-disc or band friction brake. Both types of systems are controlled using hydraulic cylinders. The signal to the clutches comes from the distribution module. And to prevent the driver from rotating in the opposite direction, the automatic transmission device has an overrunning clutch.

Let's consider the main components of an automatic transmission, as well as the principle of their operation.

1. Hydraulic transformer.

This device changes the torque and its subsequent transmission, thanks to the working fluid. As a rule, a ready-made composition for automatic transmissions is used as a working mixture. The use of analogues is highly undesirable for the correct operation of all components of the mechanisms and preserving the service life of the box.

1. Reducing mechanism.

It is a set of working elements in the form of gears. The gearbox is the most important mechanism of an automatic transmission and requires some attention when operating a vehicle.

1. Control set. The entire operation of the machine is controlled using a special system included in the machine.

The combination of these elements ensures automatic gear shifting. Let us consider in more detail the main features of the constituent elements and their role in the operation of the system.

Control system

Now it is impossible to imagine an automatic transmission whose operating principle would not depend on electronics. Thus, this system includes various sensors, a distribution module and a control unit. During automatic transmission operation, the system reads information from various elements. This is a sensor for the temperature of the ATP fluid, the speed of the output and input shafts, as well as the accelerator position. All these signals are processed in real time. Then the control unit generates control pulses that are sent to the actuators. We also note that the operating principle of the automatic transmission valve body is based not only on reading data from sensors, but also on matching signals that are available in the electronic engine control unit.

The distribution module is responsible for controlling the flow of working fluid and the operation of friction clutches, which consists of:

• Solenoid valves (they are mechanically driven).
• Spool valves.
• Aluminum case, which contains the above parts.

When considering the operating principle of a Toyota automatic transmission, it is important to note such a thing as solenoids. These parts are also called solenoid valves. What are solenoids used for? Thanks to these elements, the pressure of the ATP liquid in the box is regulated. Where does oil pressure come from? This task is performed by a special automatic transmission gear pump. Its operating principle is simple. This element operates from the donut hub. I rotate with a certain frequency, it captures a certain volume of oil with the impellers and pumps it. And so that the working fluid does not overheat and the operating principle of the car’s automatic transmission is not violated, some gearboxes have a radiator in their design. It can be placed separately in the front part (hidden under the bumper) or connected to the main cooling radiator. The latter scheme is often practiced on Mercedes cars.

Selector

The operating principle of the automatic transmission selector is extremely simple. This mechanism is structurally connected to the spool, which performs a certain operating mode of the automatic transmission. There are a few of them:

• Parking.
• Reverse.
• Neutral.
• Drive.

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But that is not all. If we consider the operating principle of the Honda automatic transmission, you will notice that the selector has a sport mode. To turn it on, just move the handle to the appropriate position. Considering the principle of operation of the Nissan automatic transmission, it is worth saying that on some models there is the possibility of manual gear shifting.

Automatic car: start

Having dealt with the lever, we adjust the driver’s seat and mirrors (to do this correctly, it is better to take additional driving lessons on an automatic transmission) and try to start the engine:

1. Insert the key into the ignition. Make sure the lever is in “P” or “N” and apply the brake.
2. Turn the key to “engine start”. Don't let go of the brake pedal!
3. Move the lever to “R” or “D” and release the brake. Remove the car from the handbrake. Go!

Important: If you haven't taken an automatic transmission driving lesson yet, just remember: you are a one-legged pirate - with only one right foot for the gas or brake. There is no left one, forget about it.

Robot DSG

This type of automatic transmission appeared relatively recently. The first models began to be used only in the mid-2000s. Initially, such boxes were installed on Skoda cars. But they can also be found on Volkswagen and Audi.

Among the features, it is worth noting a completely different operating principle of the automatic transmission. There is no torque converter as such here in principle. Instead, a double-disc clutch and a dual-mass flywheel are used. This design allows you to significantly reduce the time interval between gear changes.

If we talk about the device, the design of this box includes:

• Manual transmission with two rows of gears.
• Electronic control system.
• Differential.
• Main gear.
• Double clutch.

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All of the above elements are enclosed in a single metal case. Why does the design use a double clutch and two rows of gears? If we consider the principle of operation of the automatic transmission of a car with DSG, it should be noted that while one gear is in operation, the second is already preparing for subsequent engagement. This happens when accelerating and when decelerating. Friction clutches are also present in such a gearbox. They are connected through the main hub to the gear rows in the transmission.

There are several types of DSG boxes:

• Six-speed.
• Seven-speed.

The operating principle of the first type of automatic transmission is based on the action of a “wet” clutch. So, the box contains a special oil that provides not only lubrication, but also cooling of the clutches. Fluid under pressure circulates in the system and transmits torque.

As for the second type of DSG, a dry clutch is already used here. The operating principle is similar to a manual transmission - the disc is pressed against the flywheel and transmits torque through friction. According to experts, this design scheme is less reliable. The service life of the discs is about 50 thousand kilometers, and the cost of replacement reaches $700 including consumables.

The gear rows include reverse, even and odd speeds. Each row is a set of shafts (consisting of a primary and secondary), as well as a specific set of gears. To achieve backward movement, the design uses an intermediate shaft with a reversible gear.

Like a classic automatic, there are electronics that control the gear shift. This includes the control unit, sensors and actuators. So, first, the sensors read data about the rotation speed of the shafts and the position of the gear fork, and then the unit analyzes this information and applies a certain control algorithm.

The DSG hydraulic circuit consists of:

• Spool valves that operate from a selector.
• Solenoid valves (same solenoids). They are used to change gears in automatic mode.
• Pressure control valves, which contribute to the smooth operation of the friction clutch.

Starting and stopping with automatic transmission

Most drivers who switch from a manual to an automatic transmission initially automatically perform actions that they are accustomed to performing repeatedly when driving a car with a manual transmission. Therefore, before starting to drive with an automatic transmission on the road in general traffic, such drivers are advised to first practice alone.

So, the standard procedure for starting a car with an automatic transmission is as follows:

• Insert the key into the ignition.
• Depress the brake pedal with your right foot (the left foot is not used when driving with an automatic transmission).
• Check the position of the gear shift lever - it should be in the “P” - “parking” position.
• Start the engine (with the brake pedal pressed).
• Also, with the brake pedal pressed, switch the PP lever to position “D” - “drive” (moving forward).
• Fully release the brake pedal, after which the car will move off and begin to move forward at a low speed - about 5 km/h.
• To increase the speed, you need to press the gas pedal. The harder you press the gas pedal, the higher the gears and speed will be.
• To stop the car, you need to remove your right foot from the gas pedal and press the brake pedal. The car will stop.
• If you plan to leave the car after stopping, then with the brake pedal pressed, move the gear lever to the “P” - “parking” mode. If you need to stop in a traffic jam, at a traffic light or a pedestrian crossing, then, naturally, there is no need to switch the PP lever to “parking”. Once you decide to continue driving again, release the brake pedal and press the gas pedal to increase speed.

Many modern automatic transmissions have an imitation of the mechanical gear shift mode “M” (as on a manual transmission) for up/down gears using the “ ” and “–” buttons on the gearshift lever. That is, the driver is given the opportunity to manually increase or decrease gears, taking away this function from the “automatic”. In this case, the transition to a mechanical gear shift mode can be made while driving, when the car is already driving in “D” mode.

To prevent engine damage when switching to manual mode “M” while driving, all automatic transmissions have special protection. Switching to manual control “M” is relevant in the following situations:

• When driving off-road, use a lower gear to avoid slipping.
• When coasting down a hill, with engine braking. It is not recommended to use the neutral “N” mode for coasting, as it is harmful to the automatic transmission. And coasting in “D” mode is not entirely convenient, since there is a gradual decrease in speed.
• For comfortable cornering and other maneuvers, including sharp acceleration when overtaking.

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How does DSG work?

The operating principle of the robot's automatic transmission hydraulic system is to sequentially switch a number of gears. When the car starts to move, the system switches to first gear. In this case, the second one is already engaged. As soon as the car reaches a higher speed (about 20 kilometers per hour), the electronics switches the speed to higher. The third gear is already engaged. This happens all the way up to the highest level. If the car slows down, the electronics engage a lower gear. Switching is carried out instantly, since the design involves two rows of gears.

Parking on a slope

There are times when, when driving an automatic transmission, the car stands on a hill. The driver removes it from “parking” and at this time an unpleasant grinding noise is heard.

This may cause the parking tooth to grind because the car with an automatic transmission was parked correctly on the hill. In this case, the automatic transmission may break down. When a car with an automatic transmission is parked on a hill, you must first put it on the handbrake, and only then put it in “park”.

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And when you start driving downhill or uphill, you first need to press the brake with your foot, remove the car from the handbrake, and only then move the automatic transmission lever to the “reverse” or “drive” position.

Application

It is worth noting that such a transmission is not used on every car. As we said earlier, the bulk are cars from the VAG concern. But commercial vehicles (for example, Volkswagen Crafter) are not equipped with them. And all because the box is designed for a certain torque threshold. It should not exceed 350 Nm.

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This applies to six-speed transmissions. DSGs at seven speeds cannot withstand more than 250 Nm at all. Therefore, you can find such a box on the Tuareg and weaker cars like the Passat or Octavia.

Variable speed drive

This gearbox also operates in automatic mode. It appeared half a century ago, but has only become actively used in the last 10-15 years. What is a variator? This is a continuously variable automatic transmission that smoothly changes the gear ratio through a belt or chain drive. Gear ratios change as the vehicle gains speed. At the moment, such a box is widely used by the following automakers:

• "Nissan".
• "Mercedes".
• "Honda".
• "Audi".
• "Subaru".
• "Toyota".
• "Ford".

What are the advantages of this box? Thanks to the smooth change in gear ratio, the car picks up speed quickly and without jerking. The driver and passengers do not feel shocks during acceleration, no matter how hard the accelerator pedal is pressed. However, there are pitfalls here. This box also has torque limitations, like the DSG. Therefore, it is mainly used on passenger cars.

Automatically around the city

We assess the situation using the rear-view mirrors (is the horizon clear?), then turn on the turn, move our right foot from the brake to the gas - and smoothly move towards the roadway. Let's remember the traffic rules. We move together with our colleagues in the traffic flow, not forgetting about the distance. With an automatic transmission, you don't have to change gears according to the speed limit - you have the opportunity to concentrate directly on the road situation. Driving with an automatic transmission is good for beginners because it teaches you to monitor the road situation.

A hill has appeared - evaluate how steep the climb is, whether the road surface is smooth and “what the weather is like.” Everything is alright with them? Try to enter without slowing down, on the contrary, accelerating - 30 meters before the point of the beginning of the climb, press the accelerator pedal. The inertia of the car will increase.

If the road is broken or the weather is bad (rain, snow, ice), you will not be able to coast up the mountain. Move to the far right position on the track. Climb hills at low speeds. If it is too steep, use downshifts on the automatic transmission. This is L or D3, 2.

You will coast down, releasing the accelerator. The brake pedal is needed to regulate the speed limit. Automatic driving lessons with an instructor will help you develop these skills, as well as the necessary ability for any driver to reverse when the selector is turned to “R”.

Varieties of CVTs

There are several types of transmission data:

• Toroidal.
• V-belt variator.

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Moreover, both types of boxes have almost the same structure and operating principle. The design of the variator includes:

• Control system.
• A pulley that transmits torque.
• Chain or belt drive.
• Transmission release mechanism (used to engage reverse gear).

In order for the transmission to perceive torque, the clutch is engaged in the design. It can be of several types:

• Centrifugal automatic.
• Electronic.
• Multi-disc.

There are also CVTs where a torque converter is used as a clutch (as on classic automatic transmissions). Typically, this scheme is practiced on Multimatic gearboxes from Honda. Experts believe that this type of clutch is the most reliable and durable.

Operating principle of automatic transmission

Several types of automatic transmissions with their own characteristic features are installed on vehicles.

In a simplified way, the mechanism of operation of a classic automatic transmission consists of transmitting torque from the engine crankshaft to transmission devices, while the gear ratio varies in accordance with the position of the selector lever and the driving conditions of the vehicle.

When the engine starts, working fluid enters the hydraulic transformer and the pressure increases. The blades of the centrifugal pump begin to move, the reactor wheel and the main turbine are motionless in this mode.

When you switch the selector lever and supply fuel using the accelerator pedal, the pump blades increase speed. The increasing speed of the vortex flows begins to rotate the turbine blades. The oil vortices either spread to the stationary reactor or return back to the turbine, increasing its efficiency. The torque is transferred to the wheels, and the car begins to move.

Upon reaching the required speed, the pump wheel and the bladed central turbine move at the same speed, while the vortices of the transmission fluid enter the reactor wheel from the opposite side (movement is possible only in one direction) and it begins to rotate. The unit switches to the hydraulic coupling state.

If the resistance to the wheels increases (uphill movement), the reactor wheel stops rotation and adds torque to the centrifugal pump. When the required speed and torque are reached, the gear in the planetary unit changes.

The electronic control unit transmits a command, as a result of which the braking band and friction discs slow down the downshift, and the increased movement of fluid flows through the valve accelerates the upshift and ensures gear changes without reducing power.

When the machine stops completely or the speed decreases, the pressure of the working fluid decreases and the gear decreases.

When the engine is stopped, there is no pressure in the torque converter, so starting the car with a push is impossible.

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Drive unit

As we have already said, the variator can use different drives - chain, or belt. The latter is more popular. The belt runs on two pulleys, which form conical disks. These pulleys can move and move apart depending on need. To bring the disks closer together, the design includes special springs. The pulleys themselves have a slight angle of inclination. Its value is approximately 20 degrees. This is done so that the belt moves with minimal resistance while the box is operating.

Now about the chain drive. The chain on an automatic variable transmission consists of several metal plates that are connected by axles. As experts say, such a drive and design is more flexible. The chain is capable of bending at an angle of up to 25 degrees without loss of service life. But unlike a belt drive, this drive has a different operating principle. The automatic transmission transmits torque through point contact with the pulleys. High tension (friction force) is generated in certain areas. This achieves high efficiency. And so that the pulleys do not wear out from such stress, they are made of high-strength bearing steel.

How to use an automatic transmission

According to auto mechanics at service stations, the main malfunctions of automatic transmissions appear as a result of violation of operating rules and untimely maintenance of the box.

Operating modes

Depending on the type of automatic transmission, there are different automatic transmission modes. Each position of the selector lever or button on it is designed for different driving conditions with its own characteristics.

The main types of automatic transmission modes and their impact on vehicle operation:

• P (parking) - locking the drive wheels and gearbox shaft, used only when parked and warming up;
• N (neutral) - the shaft is not blocked, the car can be towed, equivalent to neutral gear for a manual transmission;
• D (drive) - driving in normal conditions with automatic gear selection;
• L (D2) - low gear for driving in difficult conditions - off-road, steep descents and ascents, speed less than 40 km/h;
• D3 - downshifting for small descents and ascents;
• R (reverse) - reverse movement, activated when the vehicle comes to a complete stop and the brake pedal is pressed;
• O/D - engaging fourth gear when driving at high speed;
• PWR - sport mode, to improve dynamic qualities, gear increases occur at higher engine speeds;
• Normal - for smooth and economical movement;
• Manu - manual gear mode, recommended for use in winter.

How to start a car automatically

The operating features of an automatic transmission require proper starting. To protect the box from incorrect actions and subsequent breakdowns, degrees of protection have been developed.

When starting the car, the selector must be in the “P” (park) or “N” (neutral) position. Only in such positions will the protection system allow the engine start signal to pass through. In other positions of the lever, it will not be possible to turn the key or there will be no changes after turning the key.

To start, it is better to use the parking mode, since the drive wheels of the vehicle will be blocked and this will not allow it to roll away. Neutral mode should only be used for emergency towing.

In addition to selecting the correct mode, to start the engine in most cars with automatic transmission, you need to depress the brake pedal, which is also protection and saves you from accidentally rolling back the car when the selector is in neutral mode.

Most modern cars are equipped with a steering wheel lock and an anti-theft lock. If, after correctly performing all the previous steps, the steering wheel does not turn and the key does not turn, the protection has turned on. To unlock, you need to insert the key into the ignition and try to turn it carefully, while simultaneously turning the steering wheel in different directions. If these actions are synchronized, the blocking will be removed.

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How to drive an automatic transmission and what not to do

Proper driving of a car with an automatic transmission will increase the service life of the transmission and save a lot of money and nerves.

To ensure long-term operation of the automatic transmission, it is necessary to correctly select modes depending on operating conditions.

To drive properly with an automatic transmission you should:

• move off after a push indicating full engagement of the gear;
• in slipping conditions, you should engage a lower gear and, using the brake pedal, control the slow rotation of the wheels;
• using different modes you can apply engine braking or limit acceleration;
• it is possible to tow a vehicle with the engine running at a speed of no more than 50 km/h in the “neutral” selector position and for a distance of no more than 50 km;
• It is not recommended to tow another vehicle; if necessary, the towed vehicle must be no heavier than the towing vehicle, select D2 or L mode and speed up to 40 km/h in smooth motion.

What you should not do when driving with an automatic transmission:

• It is forbidden to turn on the “P” mode - parking when the car is moving;
• driving in neutral downhill;
• push start;
• when stopping for a short time (at a traffic light, in a traffic jam), select parking mode or neutral, this reduces the life of the automatic transmission;
• when stopping for a long time in city mode, the selector must be put in the “parking” position;
• It is prohibited to engage reverse gear from the “drive” mode or until a complete stop;
• You cannot first set the parking mode on a slope; when parking a car on a slope, you must first put the hand brake on and then put the “parking” selector position. To start moving from a slope, first press the brake pedal, then remove the car from the handbrake, and only then select the mode for movements.

How to operate an automatic transmission in winter

Harsh weather conditions in winter bring a lot of worries and problems to owners of cars with automatic transmission.

Recommendations for proper operation of a car with automatic transmission in winter:

• correct warming up of the gearbox - the vehicle should warm up for a few minutes after starting; before driving, it is recommended to turn on all modes one by one with the brake pedal depressed to speed up the warming up of the transmission oil;
• the first 5-10 km after starting to move, sudden acceleration and wheel slip should be avoided;
• to get out of the snow or ice, you need to engage a lower gear and, using alternating operation of the brake and gas pedals, carefully drive out;
• swinging is not recommended, as this method will have a detrimental effect on the torque converter;
• using low gears or semi-automatic mode for engine braking on more or less dry road surfaces, and using the brake pedal on slippery slopes;
• on icy slopes, you should avoid wheel slipping and sudden pressing of the accelerator pedal;
• A short-term, but clear and accurate transition to the “neutral” mode helps stabilize the car by aligning the rotation of the wheels and getting out of a skid.

Control system

Similar to previous automatic transmissions, the CVT uses an electronic control system. However, its operating principle is somewhat different. Thus, the system ensures adjustment of the diameter of the variator discs.

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As the speed changes, one pulley diameter increases and the other decreases. The modes are controlled through the selector thanks to the automatic transmission sensor. The operating principle of a variator with a chain drive and a belt drive is to change the diameter of the pulleys.

About problems

Due to the complex design and low prevalence, many services refuse to work with such transmissions. Therefore, CVTs have taken root poorly in our country. As operating experience has shown, the service life of this box, even with proper maintenance, is no more than 150 thousand kilometers. In view of this, it is wise to buy such cars only in new condition, which are under warranty. Taking a car with a CVT from your hands is dangerous - you can end up with expensive repairs, which not every service will undertake.

Designation of gears on an automatic transmission (automatic transmission modes)

Let's start with the fact that although there are different types and types of automatic transmissions, the designations on them are almost the same. The fact is that manufacturers strive to simplify the process of interaction with the unit as much as possible.

This is done so that the driver does not experience any difficulties or difficulties when changing from a car, for example, with a “classic” hydromechanical automatic transmission to a car with a CVT variator or a robot.

Even if we take into account that the automatic transmission selector on different cars may differ, the letters and numbers on the automatic transmission, which indicate the main and additional modes, will be almost the same.

So, taking into account the fact that the designations will necessarily be present on different automatic transmissions, a correct decoding of the automatic transmission and the various modes of a particular unit is needed. In other words, understanding why a separate mode is needed allows you not only to operate the car more comfortably depending on the conditions, but also to avoid breakdowns of the automatic transmission, etc.

As a rule, no matter what kind of automatic transmission it is, the designations of letters and numbers will be similar for automatic transmission, CVT, AMT type robot, DSG, Powershift, etc. In most cases, there is a lever in the cabin that resembles a manual transmission lever, with letters and numbers printed nearby.

• “P” means parking (parking mode, putting the car into parking). The mode is designed for long-term idle vehicles. In this mode, you also need to start the engine with an automatic transmission, and the car will not roll forward or backward, since a special locking mechanism is automatically activated.

The only thing is that turning on the “parking” mode is prohibited until the car is completely stopped. Also, if the car is parked on a slope, you need to additionally use the parking brake (handbrake), and first tighten the handbrake, after which the “P” mode is turned on. This will relieve the load and increase the service life of the locking mechanism.

• "R" means reverse or reverse mode (reverse gear). The mode also needs to be turned on only after the car has come to a complete stop.

If the car is parked on a slope, you need to hold the car with the brake pedal, and then move the automatic transmission lever to “R” mode. Please note that if you turn on reverse mode while the car is moving, this can lead to serious damage to the gearbox.

• “N” stands for neutral, similar to neutral on a manual transmission. For ease of understanding, the service mode is intended for towing a car. The engine can also be used, but it must be taken into account that the car may roll if you do not press the brake or tighten the handbrake.

Let’s also add that on most automatic transmissions (except for single-disc AMT robots) there is no need to switch to neutral during short-term downtime at a traffic light, in a traffic jam, etc. If the car sits motionless for 10 minutes. or more, but the engine is running, then you can move the lever to position P or N. In the case of “neutral”, you must use the handbrake or keep the brake pedal depressed.

• “D” (drive) or “A” (automate) is a mode for moving the car forward, and the gears will change automatically.

This is the main mode, used for driving around the city and on the highway in all cases, except for difficult conditions (snow and ice, large slopes, long climbs). In simple words, after turning on the “D” mode, the driver is no longer distracted by the gearbox throughout the entire trip.

• “M” (manual) indicates the possibility of manual control (Tiptronic mode), when the driver is able to control the gear shift independently (not available on all automatic transmissions).

This mode is semi-automatic; to increase the gear you need to move the selector towards o, to downshift towards o. Also, on some cars, it is possible to switch using steering column switches (paddle shifters) or by pressing a separate rocker button, which is located on the selector lever.

• “L” (low, lower), “B” (bottom, down), as well as the designations 1L, l, L1 or simply the number 1 means engaging first gear without the possibility of further switching the box to higher gears (2, 3, 4, etc.). d.)

The mode must be activated if the car is moving along a steep descent or ascent (an additional effect of engine braking appears), pulling away with a loaded trailer, or moving on ice or snow. As a rule, turning on this mode while driving at speeds above 20-30 km/h is strongly not recommended. First you need to stop, and then put the box into low gear.

Please note that on some car models (usually crossovers with automatic transmissions and SUVs), the letter “B” may mean that the differential lock is engaged.

In this case, it is prohibited to turn on the mode while driving; you also cannot drive in this mode at a speed above 20-30 km/h, etc. To avoid transmission breakdowns, you must separately study the manual for a specific model.

• L2, 2L or simply 2 means forward movement, and the transmission will not shift above 2nd gear. This mode is suitable for driving at low speeds (30-40 km/h) on roads where there are frequent descents and ascents, bad road conditions, etc.

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D3 or number 3 is a mode that is similar to the previous one, but the automatic transmission will not shift above 3rd gear. The mode is activated when a pronounced engine braking effect is required, the car moves at speeds of up to 80 km/h on roads with frequent descents and ascents, in the case of constant acceleration to medium speeds and subsequent frequent stops (for example, driving in the urban cycle). Acceleration dynamics at speeds of 40-80 km/h are also improved.

• D4 or 4 (usually this mode is found on 4-speed automatic transmissions and is similar to mode “D”) means that all 4 gears will be engaged (from 1st to 4th), that is, the box uses the entire range and operates normally automatic mode.

If driving conditions are normal (driving on flat roads, without unnecessary loads, at an average speed of 80-100 km/h), then this mode is optimal and most economical in terms of fuel consumption.

• The OD (over drive) mode is analogous to the D3 mode. Automatic transmission overdrive is needed to disable overdrive (4th, 5th, etc.) In this case, O/D off lights up on the instrument panel. Turning on and off is usually done with a separate button, which is located next to the box lever.

This mode is needed if the speed is average and constantly changing (for example, 50-70 km/h). At a speed of 60 km/h, the switch to 4th gear already occurs, but then the speed decreases and 3rd gear is switched on again.

We also recommend reading the article on how to properly drive a robotic gearbox. From this article you will learn how to operate a robot box, as well as what you need to consider when driving a car with a manual transmission.

Such constant switching leads to increased wear of the automatic transmission; traction when switching to 4th gear also deteriorates, since this is an overdrive gear. For this reason, it is recommended to use overdrive in busy cities, when overtaking is necessary, and also on long climbs. The main thing is to turn off OD after picking up speed above 80 km/h.

• Among the additional modes, the “S” (sport) mode should be highlighted, which allows the box to delay the moment of switching. In other words, in each gear the engine will spin up to high speeds, which is necessary for active driving, overtaking, sharp acceleration from a standstill, etc.

The complete opposite is the “E” (economic) mode, which is designed for a calm and smooth ride. Gears are switched as early as possible so as not to spin the internal combustion engine, since the main goal is maximum fuel efficiency.

“W” (winter, winter, also indicated in the form of a snowflake *) or snow is a winter mode. This mode allows a car with an automatic transmission to move off smoothly, avoiding slipping in snow or ice. As a rule, on some automatic transmissions the start begins immediately from second gear; on other automatic transmissions, the electronics distribute the torque so that the wheels do not slip.

You should study the car manual separately to understand exactly how to use this mode. In some cases, many manufacturers do not recommend long-term use of winter mode; it is prohibited to drive at speeds above 20-30 km/h, etc.

You can also select the kick-down mode (kick down, hit the floor). This mode is activated when the driver presses the gas pedal all the way. In this case, the box immediately lowers the gear 2-3 steps lower, spinning the engine to maximum. As a rule, this mode is needed for overtaking.

Let's sum it up

So, we have found out the structure and operating principle of hydromechanical automatic transmission, robotic and variator. As you can see, all these boxes are designed differently and have their own algorithm of action. Which transmission is better to choose? Experts say that the most reasonable choice would be a classic machine gun. As operating experience has shown, owners of cars with DSG and CVT often contacted services and these boxes are expensive to maintain. The classic machine has been on the market for a very long time, and its design is constantly being refined and improved. Therefore, such boxes have a high service life, are unpretentious in operation and can be repaired at any service center. Practice has shown that the service life of an automatic transmission in a passenger car ranges from 300 to 400 thousand kilometers. This is a serious period, given that some modern engines only last 250. But in order for such a transmission to last for a long time, it is worth changing the ATP fluid in it regularly, namely every 60 thousand kilometers.