Today, cars with various types of automatic transmissions are actively replacing models with a traditional manual transmission. Even taking into account the higher cost, a car with an automatic transmission provides greater comfort and also greatly simplifies the operation of the vehicle (especially if we talk about novice drivers).
At the same time, taking into account the apparent ease of operation, the “automatic” also needs to be used correctly. In other words, you need to know how to operate an automatic transmission, since certain errors can lead not only to a reduction in service life, but also to serious damage to the automatic transmission.
In this article we will look at the modes and features of the “classic” hydromechanical gearbox, since robotic manual transmissions (AMT) differ from automatic transmissions and will be considered separately.
How to drive an automatic - features of cars with automatic transmission
In an automatic transmission, gear shifting is carried out only depending on the speed. When a certain threshold is reached, a transition occurs from one stage to another. This is accomplished thanks to built-in electronics and gear pairs controlled by solenoids. There is also a clutch that ensures a smooth transition from one stage to another.
As practice shows, driving an automatic is much easier than driving a car with a manual transmission. Everything is explained by the operating principle of the automatic transmission and the absence of a third clutch pedal. It is important to remember one thing: every time at the beginning of a standing start, you should press the gas pedal smoothly.
Features of a car with automatic transmission include:
- simplicity and ease of operation of the machine;
- no need to change gears yourself;
- Modern automatic transmissions have no shorter service life than mechanical ones.
The history of the automatic transmission
The idea of creating an automatic transmission belongs to the German engineer Hermann Fettinger, who developed the first torque converter in 1902, and at first such a transmission was used only for the construction of ships.
The first car equipped with a planetary automatic transmission was the American Ford T. After the release of this car, the most active role in the development of automatic transmissions was played by General Motors, which managed to release a semi-automatic transmission in the mid-1930s. The same GM created the first completely automatic transmission in 1940
Basic operating modes of automatic transmission
In cars with automatic transmission, there is no need to change gears. This transmission is equipped with an operating mode switch that determines at what point the transition from one stage to another will occur. The automatic transmission is controlled by buttons and a lever. In this regard, the transmission, on the contrary, is somewhat complicated, because in a manual car there is only a lever and a pedal. Despite the increased number of controls, the control process is much simpler. It is important to know that such a transmission has primary and secondary operating modes. The first include:
- “P” - this Latin letter indicates the activation of the parking mode. The drive wheels are locked and the engine is disconnected from the transmission. It is in this position of the lever that the motor should be started, since there is no load on its shaft.
- “R” - the position of the transmission lever in this mode indicates that reverse gear is engaged. It is activated electronically and only when the machine is completely stopped.
- “N” - if you plan to tow a car, then you need to do it in this mode. The motor is disconnected from the transmission and the drive wheels are not locked.
- “D” - this position of the lever indicates forward movement. It should be turned on whenever you travel.
- “M” - this sign on the automatic transmission indicates that the automatic transmission’s gears are shifted manually, but it is not available on all car models with similar gearboxes.
Additional automatic transmission operating modes
To properly use an automatic transmission, you need to learn additional operating modes. They are also called submodes. Perhaps not all modifications of the boxes will be marked exactly as will be described later in the article:
- Overdrive mode is designated “D” or “O/D”. It is designed for long periods of driving at high speeds. Used outside the city.
- The letters “D3” or “O/D OFF” indicate turning off the overdrive mode. It forcibly disables the 4th stage so that it does not operate during a short-term increase in speed. Allows you to save the life of the torque converter clutch when driving around the city.
- The position of the lever at the “S” or “2” marks indicates the activation of the reduced speed mode. It should be turned on if you plan to drive slowly for a long time. It is used for confident movement on icy roads. In some car modifications, the position is marked with the letter “W”.
- The position of the lever at the “L” or 1 mark means that only the first stage is turned on. It is used in transmission diagnostic or repair mode. You can also turn it on to start on uneven surfaces and then move at creeping speed.
Modes of modern cars
In modern automatic transmissions, to improve vehicle traffic safety, an additional emergency mode has been introduced. It is often not marked in any way, but the system automatically switches to it if a problem is detected in the stage control mechanisms or components. The driver learns about its activation by the corresponding pictogram on the dashboard. In this position, it is possible to drive at a minimum speed, which should be enough to get to the car service center.
Also in modern boxes there are the following operating modes:
- d overdrive;
- Kick down;
- Pwr sport;
- Snow.
Od overdrive _
Learning to drive a car with an automatic transmission includes the use of the O/D overdrive mode. It was already mentioned earlier in the article, but it’s worth remembering. It is needed to block the 4th stage when driving with a short increase in speed. Forced disconnection of the torque converter clutch of this transmission saves its resource. The mode is activated by pressing or releasing a button located directly on or near the lever. The shield usually has a yellow warning indicator.
It should be turned on when driving in traffic at a speed of 40-60 km/h and frequently pressing the brake pedal. If you turn it off, the car will become noticeably slower, since getting out of the 4th stage requires high speed, and when in traffic this is not acceptable.
Kick down
If you press the gas pedal sharply, the so-called Kick down mode is automatically called up. This leads to the switching off of the higher stage and transition to the lower stage. This mode is needed to maintain a smooth speed increase and avoid sudden transitions. When the revolution reaches the desired level, the proportion of upshifts will occur, and a transition to a higher gear will occur.
Pwr sport
In Pwr sport mode, upshifting occurs when the maximum speed in the current gear is reached. This ensures the best dynamics, and the engine develops maximum power. Used when driving at high speeds.
Snow
Snow mode is activated when driving on slippery or wet roads, where traction is noticeably worse. If it is activated, then when the gear lever is in position “D”, the car starts off in the second stage.
Is it possible to change automatic transmission speeds on the go?
The presence of gas and brake pedals in the cabin indicates the presence of an automatic transmission in the car. This obliges the driver to learn how to use it correctly. While in motion, that is, when the car is not standing still, there are not many actions that can be performed. For example, you cannot shift the automatic transmission while driving:
Switch from D to N so that the car coasts without steps. This will lead to loss of connection with the wheels and an emergency situation on the road.
You can switch:
- Enable or disable the 4th stage D/O blocking mode.
- Switch from D to S mode for high-speed driving on the autobahn.
- Change gears when manual control is activated, that is, “M” mode. It is not available on all modifications of boxes. Allows you to switch between modes “1” or “L”, “2” and “3”, respectively, at a maximum speed of 25, 50 and 120 km/h.
Automatic transmission device
An automatic transmission has a complex structure and the mechanism itself, through which gear shifting is ensured, is complex. The essence of this process comes down to turning the clutches and brakes on and off using the pressure of the working fluid.
There are several types of automatic transmissions that have some differences in design, but their basic elements are the same.
- Hydraulic transformer (torque converter)
. It is a metal body that is filled with a special working ATF fluid (oil). Its main task is to transmit rotation from the engine to the gearbox. In fact, this is an analogue of the clutch in a manual transmission. Consists of pump, turbine and reactor wheels, locking clutch and freewheel. The wheels have blades with holes for the circulation of working fluid. A freewheel is needed so that the reactor wheel can rotate in the opposite direction. The lock-up clutch allows you to lock the torque converter under certain vehicle operating conditions. - Planetary mechanism.
This is a gearbox that changes speeds as a result of changing the gear ratio on the gears. Consists of: planetary gears (sun gear, satellites, ring gear, carrier), shafts, drums with friction clutches, overrunning clutch and band brake. Blocking one of the elements of the planetary gear leads to the transmission of rotation and a change in torque. The planetary gear set can be locked by a band brake, an overrunning clutch and friction clutches. The planetary gear acts as a block of gears in a mechanical box. - Hydraulic system
. Consists of an oil pump, filter, pushers, hydraulic distributor. The working fluid creates working pressure in the box and protects internal elements from overheating and corrosion.
- Electronic control unit.
Collects incoming information from pedals, ABS and ESP systems, sensors, automatic transmission knob and other systems, processes it. Then it generates signals that are sent to the valve body actuator valves. The control unit regulates the operation of the friction clutches and directs the flow of working fluid to one or another clutch, which leads to a speed change. That is, the control unit is literally the “brain” of the automatic transmission; it controls the gearbox. A breakdown of the control unit leads to the machine switching to emergency mode.
Driving an automatic - starting the engine of a car with automatic transmission
Automatic driving lessons involve practice starting the internal combustion engine and the first start. It would seem what difficulties there could be with such a transmission. I turned on “D” and went. This is possible, but the service life of the box will be greatly limited, because incorrect operating modes lead to excessive load on it, which will require repairs much sooner than expected.
Important . Driving a car with an automatic transmission is easier and safer, since the software has strict rules for changing speeds that the driver cannot influence. He only has the power to set the desired operating mode, which must correspond to the road situation.
It is worth noting that automatic transmissions differ from each other in various ways, so the actions can also be different between them. Starting from the number of additional modes, ending with the design features of the unit and the stroke of the lever. Therefore, before going on a big road, it is recommended to study the features of driving a car with such a transmission.
To properly start an engine with an automatic transmission, you need to move the gear selector lever to “P” or “N” mode. The engine will be disconnected from the transmission and will be easier to start when cold.
Important. It is impossible to start the car with the modes “D”, “R” or “M” turned on. A protection is activated that will block the start, since in this position there is a high probability of a breakdown.
Tips and recommendations for operating automatic transmissions
First of all, when operating a hydromechanical automatic transmission, you should avoid operating such a box without preheating. This means that the automatic transmission needs to be warmed up before the trip, regardless of the outside temperature.
In practice, this means that after parking, it is advisable to start and warm up the internal combustion engine, and after a slight warm-up of the engine, the brake pedal is pressed, after which the automatic transmission mode selector is held in each position for 30 seconds. up to 1 minute.
Then you can start driving, but for the first 3-5 kilometers you should avoid active acceleration, use kick-down mode, etc. In other words, increasing the load on the automatic transmission is not allowed.
It is important to remember that the automatic transmission contains a large volume of ATF (transmission oil), the viscosity properties of which depend on temperature. At the same time, the automatic transmission is very sensitive to the quality and viscosity of the oil. It is not difficult to guess that until the box warms up, the transmission cannot be heavily loaded. At the same time, the gearbox needs more time to reach operating temperatures than the engine.
- Another nuance when operating cars with an automatic transmission is that automatic transmissions can stall after prolonged slipping of the drive wheels. This means that if such a car is thoroughly stuck in the snow or mud, it is better to refuse attempts to drive out under its own power.
Otherwise, the clutches “burn”, the gearbox overheats, wears out heavily, becomes contaminated with wear products, etc. The result is expensive automatic transmission repairs, replacement of clutch packs, flushing of valve body channels, etc.
We also recommend reading the article about what automatic transmission clutches are. From this article you will learn about the principles of operation, purpose, design of friction discs of an automatic transmission, as well as frequent malfunctions of automatic transmission clutches.
The automatic transmission also wears out a lot if you tow a trailer or other cars. The reason again is overheating of the automatic transmission. We also add that the car itself with an automatic transmission also needs to be towed correctly.
Often, the manufacturer prescribes rules and recommendations regarding towing without hanging the drive wheels in the manual. Most often, you can tow a car with an automatic transmission in neutral gear, the travel speed is 50 km/h, the distance is limited to 50-60 km.
- We also add that owners of cars with automatic transmissions often wonder whether it is necessary to use the parking brake on a car with an automatic transmission. The fact is that all cars with automatic transmission have a handbrake, but the locking in P mode also works at the same time.
It should be taken into account that in the “parking” mode without using the parking brake, the entire load falls on the locking mechanism and reduces its service life. Also, one should not exclude the possibility of a mechanism breakdown while parked, that is, the “handbrake” is actually an additional insurance.
The parking brake must be used if you had to stop the car on a descent or ascent. In this situation, it is easier to switch the automatic transmission selector to mode D or reverse from mode P only when the parking brake is applied. It turns out that before you start moving, you must first press the brake pedal, then move the selector to the desired mode, and only then lower the handbrake.
How to start automatically
A car with an automatic transmission should be operated correctly. Follow the recommendations not only while moving, but also when starting from a standstill. You need to move away with such a box according to the following algorithm:
- Check the position of the selector. It must be "P" or "N". In this state, the engine is not loaded by the transmission and starting is easier; this is especially important in the cold season, when the oil is too thick.
- Before turning the ignition key, be sure to press the brake pedal and remove the handbrake, as the car may have been parked on a slope.
- Start the engine in park or neutral.
- When the engine warms up to the desired temperature, move the selector to the “D” or “R” position. Accordingly, to move forward or backward.
- It will take up to 1 second for the mode to switch. After this, release the brake and smoothly press the gas pedal.
Convenience of the machine
A number of car enthusiasts who started driving back in the Soviet era and encountered only mechanics still have concerns about automatic transmissions. Fortunately, there are fewer and fewer of them. And although no one says that automatic transmissions will replace manual transmissions in the near future, every year there are more and more of them on the roads. Using an automatic transmission correctly means increasing the efficiency of driving the car, and at the same time reducing the likelihood of breakdowns, because repairing an automatic transmission is very expensive.
The most convenient thing about operating a car equipped with such a device is that you do not need to manually select gears and change them when a certain speed limit is reached. The system automatically selects the appropriate gear ratio, which is why the box received the name “automatic”. Women and novice drivers are especially passionate about it.
How to stop driving with automatic transmission correctly
Stopping movement can be considered as braking. It comes in three types depending on the situation:
- engine braking, used in case of brake system failure;
- emergency, used in moments of sudden stop when the need arises;
- normal, the driver smoothly presses the brake pedal and the automatic transmission gradually switches gears from higher to lower.
To bring the vehicle to a complete stop from a driving position, apply the brakes, either hard or soft, and be sure to move the gear selector to the “P” position.
Important . Some people advise switching the automatic transmission to N mode, but the wheels are not locked and then the car can roll on a slight slope. Always move the lever to the "P" or park position.
How to tow a car with automatic transmission
Towing is the most dangerous operating mode of an automatic transmission. These situations should be avoided by any means, but if you find yourself in such a situation, then there is an “N” mode for this. Move the selector to this position and tow the car to the nearest parking lot or repair shop. The principle of towing a car with automatic transmission is as follows:
- Move the lever to neutral position.
- When operating the brake pedal, control the cable tension.
- Rotate the steering wheel smoothly; it will be difficult with the engine turned off.
- Since oil does not circulate in the automatic transmission, it overheats greatly, so stop the road train for 5 minutes every 20 minutes.
- Tow a car with an automatic transmission at a maximum speed of 40 km/h, as the parts in the transmission rub dry.
When towing a car with the engine running, everything is much simpler, since the units are lubricated and the steering wheel turns easily. For this reason, tow whenever possible with the engine running.
Fourth place neutral
In principle, neutral transmission and automatic transmission can coexist perfectly well with each other. Sometimes it’s even right to turn it on, for example, when you’re stuck in a huge traffic jam and don’t move (for 15-30 minutes).
BUT sometimes “neutral” can harm your automatic transmission:
- When you are rolling down a hill, you turned it on at the top (like on a manual transmission), and at the bottom you decided to turn it back to “D”, it turns out as if at speed. THIS CAN'T BE DONE! The two turbine wheels located in the torque converter rotate at different frequencies. And if you connect them hard, there may be consequences
- Also, you should not constantly pull the lever into neutral when, say, you are moving in a traffic jam in the city, and every 10 - 30 seconds you have movement. I have seen drivers who constantly switch to “N”, then again to “D”, and so on every 15 seconds while they are stuck in traffic. REMEMBER, during such switching on and off, the clutches are either compressed (the gear is switched on) or released (the gear is switched off). As a result, during one such trip there will be a lot of on-off switching, but this leads to wear of the clutches and solenoids. So if the parking lots are short, turn on “D” and drive on it
Is it possible to tow other cars with an automatic transmission?
If there is a need to tow another vehicle with a car with an automatic transmission, then this is also a heavily loaded operating mode for an automatic transmission. For this reason, it is easier and sometimes cheaper to call a tow truck rather than “ruin” the machine in another car. But if the situation is hopeless, then follow these requirements:
- Do not tow a vehicle that weighs more than your vehicle.
- You need to start driving with such a trailer as smoothly as possible and drive in a lower gear, moving the selector to manual mode or “S”, if equipped.
- Monitor the temperature of the oil in the box so that it does not overheat.
How to rebuild
The need to change lanes in traffic creates a lot of problems - you need to notice the reason for the maneuver in time, carry out the prescribed actions step by step, control the situation with the help of mirrors, change lanes without interfering with other road users. It is possible to achieve error-free maneuvering only through long-term training, which helps train muscle memory and bring reactions to automaticity. Sergey Moryakhin examines the topic in detail: he examines typical mistakes, gives instructions on execution techniques, shares tips, reinforces the material in practice, inviting the viewer to “ride” together around the city and in the process analyze real situations.
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How to drive an automatic transmission with a trailer
Driving with a trailer is similar to towing another car, only the weight of the load is less. In any case, the automatic transmission will work under increased load. For this reason, you must also comply with several simple requirements:
- If you frequently drive with a trailer, it is recommended to install an additional automatic transmission radiator to cool the oil, since under load it gets very hot and the parts wear out faster.
- If you plan to tow a trailer over long distances, then develop driving skills in low gears 2 and 3. In this state, the box is less loaded and the parts do not wear out as much.
- The more often you tow other cars, the more times you will have to turn to the services of a car service to repair your transmission: change the filter, oil and perform other work. Use only high-quality transmission fluid.
- Drive at a maximum speed of no more than 4500 rpm and do not press the gas pedal all the way.
Features of using automatic transmission in winter
Winter is the hardest time for a machine. If you do not follow the rules for using the unit in winter, it will quickly fail. Try to follow the following recommendations to extend the life of the automatic transmission:
- Before driving, you need to warm up the engine and gearbox. All fluids will become liquid again, protecting the metal components of the transmission. Warming up is simple: start the car, put the gear in Drive or Reverse. Continue the procedure until the engine warms up to 40 degrees.
- The first time after warming up, drive slowly, up to 40 km/h. Make sure that the revolutions do not rise above 2000. After 2-3 kilometers you will be able to drive as usual.
- If the road is slippery, then you need to turn at a reduced speed. Do not press the brakes and maneuver the steering wheel at the same time.
- When you warm up the car, switch the transmission selector from different positions several times. The oil will be evenly distributed throughout all compartments and will protect against excessive wear.
- If there is a significant minus outside, then try to drive in a gentle mode. Avoid sudden throttle changes, braking, and intense overtaking. This way you will protect the automatic transmission control unit.
- It is strictly forbidden to drive out of a snowdrift using a tug. If such a situation does occur, disable the traction control system. Try again several times.
How to use an automatic transmission in traffic jams and traffic lights
The automatic transmission was invented to facilitate the process of driving a car in city mode, so driving with frequent stops under traffic lights is normal. Many beginners are interested in whether they need to engage neutral when driving in traffic jams. It all depends on the type of automatic transmission. If this is a robotic gearbox, then you do not need to turn on neutral, because the actuators automatically release the clutch when you press the brake pedal.
In boxes with a torque converter, turning on the N mode allows you to prolong the operation of the unit, since in this position of the selector it is less susceptible to heating. And this is only relevant if the filter is already clogged and does not circulate well. If everything is normal, then turning on neutral does not play any role.
Video “Repairing an automatic transmission on a Mercedes”
User Alexander Sorokin published a video in which he showed how the procedure for disassembling and repairing the automatic transmission 722.6 in a Mercedes Benz car is performed.
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How to drive an automatic car - engine braking
If there is a need to brake engines with automatic transmissions, then there are two options. The first is to follow these steps:
- Activate overdrive mode. The automatic transmission automatically switches to the 3rd stage.
- If you are driving at a speed less than 90 km/h, then in manual mode, shift the transmission to the second stage. The car will immediately begin to slow down; naturally, do not press the gas pedal at this time.
- If you are moving at a speed of less than 50 km/h, then switch the transmission to “L” mode.
The second option is applicable when driving on a slope. You need to do the following:
Place the gearshift lever in mode S (up to 90 km/h) or L (up to 50 km/h).
- Do not press the gas pedal during the entire braking process.
- Periodically depress the brake pedal until you come to a complete stop or reach the set speed.
Description of winter mode “W”
The most popular among car enthusiasts is an additional program called “winter mode”.
Possible winter mode designations:
- snowflake *;
- "Snow"
- "Winter";
- "COLD";
- letter "W".
When using this program, the car on a snowy track starts moving in second gear without slipping. Subsequent gear changes are made at lower engine speeds. This is designed to avoid sudden skidding and acceleration of the car. In summer, this program is not used, because in “Winter” the automatic transmission receives additional heating due to increased loads. At subzero ambient temperatures, the oil in the transmission cools quickly, so additional heating does not pose a threat to the transmission.
It is not advisable to use the “Snow” mode when driving on clean highways inside the city, where there is relatively good coverage. It is more in demand for driving on dirt country roads in winter conditions. The most dangerous use of the winter program is when the car is slipping. It is recommended to avoid places where the car’s wheels can get stuck (slippery areas under loose snow, deep puddles on dirt roads, etc.).
How to use automatic transmission correctly when overtaking
When overtaking, dynamics are important for a car, that is, a quick increase in speed in a short time. In fact, you just need to press the gas pedal harder and the car will begin to accelerate to complete the maneuver. When you press the gas pedal all the way, the kickdown mode will automatically work and a quick but smooth increase in speed will occur. After overtaking, release the pedal and the transmission will return to normal operation.
Fifth place start, with two pedals
There is such a thing as “two-pedal start” (also called “launch control”). When you hold the brake with one foot, press the gas with the other, raise the speed - then sharply release the brake pedal, and the car slips forward.
The point of such an activity is to “start” faster on the machine. Because the speed is high (4 - 5,000), the torque converter rotates decently. On turbocharged engines, the turbine also begins to pump up pressure to its fullest. And as a result, a sharp start and a gain of about a second.
The torque from the engine is sharply transferred to the transmission (in particular the gearbox), the load goes to the clutch packs and gears. All this really wears them out. So I don't advise you to start with two pedals often.
YES, and the meaning of “LAUNCH CONTROL” is on turbocharged engines, so that the turbine spins up. ON conventional aspirated engines, the increase in time is not large, from 0.2 to 0.4 seconds (also not small, but much less than on a turbo).
Common mistakes when driving an automatic transmission
An automatic transmission is a complex unit that requires proper and careful handling. This is important because repairing it is expensive. To avoid losing money, do not do the following:
- Do not coast; this will cause the automatic transmission to overheat.
- Do not shift the transmission into reverse or park, as this will damage the unit.
- When stopping the car in a parking lot, first activate the handbrake, then turn on the “P” mode.
- Do not tow a vehicle with heavy weight or at speeds exceeding 40 km/h.
- Do not press the gas pedal when the selector is in zone N.
Types of automatic transmission
There are now three types of automatic gearboxes:
- classic automatic transmission
. When they say automatic transmission, they mean this particular type of gearbox, and in this article we are talking about this type. They are installed on most modern cars and trucks, although the other two types are gradually increasing their presence in the car market. - Robot
(robotic gearbox). It is one of the automatic transmission options. Its main feature is the presence of a clutch, which ensures quick gear changes without loss of engine power. The robot has input and output shafts, which are combined using gears, which leads to speed switching; they are controlled by a synchronizer. The robotic gearbox is usually controlled by a special electronic control unit, but can also be controlled by the driver. - The variator
does not have fixed gears, so speed shifting is very smooth. The speed mode is switched using cone-shaped pulleys at the input and output of the box. The belt connection ensures the movement of the nodes. The planetary gear is responsible for reversing. The CVT has the highest efficiency of all automatic transmissions.