Most new cars on the market today are automatics. What was once an innovation is now a familiar convenience. Most drivers choose automatic cars for themselves: it is more expensive, but easier to operate and much more durable. Cars equipped with automatic transmissions are of great attention to novice drivers: after all, manipulating the manual transmission lever requires special skill, attention and experience. However, experienced drivers also choose cars with automatic transmission for a smooth, comfortable ride and considerable freedom in driving.
What is it - automatic transmission?
Automatic transmission is a transmission for shifting gears not manually, but electronically. There are several types of such transmissions, and from them internal device usage depends.
There are three types of automatic transmissions:
- a classic gearbox running on a special gear oil that continuously circulates in a closed circuit under high pressure;
- stepless variator, in which there are no steps and the very fact of switching - gear ratios vary constantly, regardless of speed, instantly and with maximum smoothness;
- robotic mechanics is mechanical box gears, where the transition from stage to stage is carried out using independent electronic circuits.
These types differ primarily in the number of gears and the trajectory of the gear selector knob. These nuances are indicated on the casing of the unit and in the vehicle documentation. But the main functionality and components are the same for all three types.
The automatic transmission consists of the following parts:
The driver controls the interaction of these parts by setting the selector. As a rule, the designations on the automatic transmission panel are standard for different types Automatic transmission and car brands:
- "P" Park - parking lock;
- "R" Revrse - reverse;
- "N" Neutral - neutral position;
- "D" Drive - movement;
- "L" Low - slow movement.
Why can't you skid on an automatic transmission? How to drive a car with automatic transmission?
No explanation is required here - everything is perfectly simple and intuitive even for a beginner. This is the main advantage of this control system. vehicle: even an inexperienced driver can get behind the wheel. But a few important rules still exists.
Warm up the car!
It is forbidden to drive at high speed on a car with an unheated automatic transmission. Before starting the movement, you should let the engine run for a couple of minutes, remaining in place.
No off-road!
The gearbox is not designed for driving on difficult roads and rough terrain.
You can not skid on the automatic transmission!
Do not tow other vehicles or carry loads that exceed the capacity of your engine to avoid uncontrolled increase in wheel speed. This will cause overheating. gear oil, electronics malfunctions and rapid wear of the entire unit.
Don't slow down!
Careful handling, why it is impossible to slip on automatic transmission?
Failure to comply with these rules will lead, at a minimum, to the rapid wear of the car’s automatic transmission, and, as a maximum, to an inevitable breakdown. But the repair and replacement of such units is worth a significant amount. An experienced driver feels the nuances and understands what should be done in a given situation in order to avoid unpleasant consequences for himself and the car. But a beginner just needs to remember these simple rules, and then he is not afraid of any breakdowns and riding modern car will only give you pleasure.
Slipping of drive wheels in snow, mud can have a detrimental effect on the resource automatic box gears. Let's see if it is possible to slip on the machine without harming the transmission. Be sure to consider the features of off-road driving in a car with an automatic transmission of a torque converter type, a CVT and a robotic gearbox (DSG, Power Shift).
Automatic transmission and off-road
Due to the greatest distribution, the question: is it possible to slip on the machine, most often arises among car owners with a torque converter type automatic transmission. What consequences can be expected if skidding in snow, mud and off-road driving without following the recommendations?
The operation of an automatic transmission at the time of slipping
In situations where the drive wheels are slipping in mud or snow, switching is the greatest danger to the gearbox. The electronic unit transmission control changes gear ratios based on speed and engine load. The ECU focuses exclusively on (TPDZ, DMRV, gas pedal position sensor, speed sensor). Therefore, when the wheels spin, the ECU “thinks” that the car is accelerating normally and shifts up. 
It is the gear change during slippage that leads to increased loads on the torque converter and clutch packs. A similar damage to the automatic transmission is caused by a sharp change in the coefficient of adhesion to the road at the moment of slipping of the drive axle. For example, when the car is slipping in the snow, and then the wheels hit the paved area with good grip.
No less dangerous for the automatic transmission is overheating. The difference in the angular velocities of the turbine and pump wheels of the torque converter leads to intense heating of the working fluid. If the car slips in mud or snow until the moment of forced blocking of the main engine, the volume of oil circulating through the torque converter increases, which leads to an increase in temperature. With excessive heating, the oil cokes in the channels of the valve body and loses its performance. Therefore, the frequent operation of a car on the road requires a reduction.
How to ride?
Cars with DSG and CVTs
As you understand, it is possible to slip on the machine without harm to the transmission. Perhaps this is due to the principle of operation of the hydrotransformer. While slipping, the main engine smooths out shock loads. If it assumes the presence of a torque converter, then the car will endure trips on light off-road much more calmly. But at the same time, it is possible to slip only until the main engine is blocked. In general, you need to work carefully with the gas pedal to minimize increased loads on the belt and variator cones.
The disadvantage is just the lack of a torque converter. Therefore, clutch packs used in "wet" DSGs, as well as "dry" clutch discs robotic checkpoints off-road experience increased loads.
The box should cool down in case of long-term slipping.
The torque converter and friction discs are sources of heat in the Automatic transmission. If the loads are huge, then the heat, respectively, is released more. The operating temperature can not only be similar to the temperature of the motor, but even exceed it. As a result, the automatic transmission car is equipped with a special cooling system. In this case, the radiator is either built into the radiator of the cooling system, or, least of all, it is installed separately, and with all this, cooling occurs with the help of air.
An unnecessary result may appear in the event of a long slip, in the Automatic transmission, the temperature of the lubricating water increases. (ATF). This liquid may boil if heated. In this situation, this fluid stops lubricating the parts of the automatic transmission. As a result, the friction discs break.
The friction of the clutches increases their temperature from 200 0 C to 250 0 C. This can lead to box failure.
Long slipping is not necessary, the box needs some time to rest. When slipping, turning off the engine is not recommended.
If the car is not warmed up, it is better not to skid.
Similar consequences await you in this situation. The ATF has not yet been heated to the correct temperature and therefore has not reached the correct viscosity. Parts of the Automatic transmission that are subject to movement without lubrication will wear out sharply.
Before you start driving out of a snowdrift, first go to R mode with the brake pedal pressed. Stay in this position for a few minutes. Run over into motion in this case, when the torque converter itself fills with the necessary amount of lubricant and goes into working condition.
Hold transmission.
Let's take a closer look at the buildup. During slipping, a large load falls on the torque converter, which can lead to its breakdown. If the temperature rises, then the oil loses its characteristics, the pressure decreases - this will lead to cutting off the torque converter or burning out the clutches.
During a long slip, you need to delay the transmission. The most fundamental thing is switching from R to D with a fixed gear, this can be done through the brake pedal. It is not recommended to immediately press the accelerator and brake pedal.
Try to avoid getting harsh traction after skidding.
Skidding, towing or long driving at high speed - all this shortens the life of the clutches.
Inside the differential gearbox, located in automatic boxes, there are heavy gears, and an axis passes through the entire gearbox housing. If the wheel hits a hard surface during slipping, the impact can lead to axle breakage. The part pierces the body at high speed Automatic transmission.
So, try to avoid harsh traction after skidding.
What cars are not advised to skid?
The huge heat generated in the torque converter can only be unsafe if the cooling system is inefficient. In most cases, this is observed in cars with high mileage, in American cars of the 80-90s.
You can meet a box with an air cooling system in old Japanese and European cars. Vanes on the torque converter housing provide airflow for heat dissipation. It is impossible to slip an automatic machine on such a box, because. cooling occurs only during driving. Today's "Europeans" and "inhabitants of the country of the rising sun", who have such automatic transmission, are in no way among the "not leaving the snowdrift".
Tips for owners of cars and with a box - automatic, and with manual gearboxes(everyone will find something useful for himself when slipping).
- During slipping, it is better to keep the steering wheel straight in the direction of travel.
- In order to move a car stuck in the snow, sometimes you need to get out and clear the snow from under the wheel. After a small opportunity for overclocking has appeared, you can continue on your way.
- At the moment of danger of slipping, try to drive slightly in reverse side. Do not hurry. You will be able to get on a track that will provide you with acceleration to overcome the obstacle and the upcoming trip.
- To increase grip while driving, it is recommended to put corrugated floor mats from the passenger compartment under the front wheels.
- In order for the next time the movement from a place to pass unhindered, it is not recommended to brake sharply, as the tires will create a smooth surface. Under the action of rest, the wheels of the car will not stop in uncompacted snow.
- A car with an automatic gearbox does not need to skid for a long time on the spot. Try to leave "swinging". Do not forget about the position of the selector R and D, in order to create switching between modes in a short time. If there are fixed steps "1,2,3", swing in R and 2 mode. Do not forget that it is often not recommended to accelerate on snow. Under no circumstances should you step on the gas abruptly.
- A janitor's shovel is more productive in winter, unlike sapper or other shovels.
- If you cannot get out of the snow trap without the help of others, ask passers-by for help. You will get out of it easier and faster in this case if your car is pushed from behind, and in the meantime you rock the car back and forth, with the help of the correct operation of the clutch. It is necessary to alternately press the accelerator pedal, then the brakes.
- In this case, if towing will take place on a cable, the most important thing is to do it smoothly, it directly concerns the car that will free your car. Before you strengthen the cable, first check the reliability of the fastening of the eye. Then turn on first gear. When the cable begins to stretch, you can proceed to the exit. In this situation, be careful and vigilant.
On the drive wheels, while automatically selecting the desired stage.
Also, during operation, the owner may encounter the fact that the automatic transmission slips, the gears are switched on out of time, jerks, shocks, shocks of the automatic transmission, etc. occur when switching. Next, we will talk about why the automatic transmission is slipping, as well as how to fix this malfunction.
Let's start with the fact that the automatic transmission consists of three main parts, each of which performs certain functions.
- . Torque, engine-driven, is increased by a torque converter and then transferred to the planetary gearbox using oil flows and pressure.
- The planetary gearbox changes the amount of torque received from the torque converter and the output number of the gearbox in accordance with the driving modes. This happens by locking some gears and unlocking others. Set and brake mechanisms, responsible for switching between gears, block and stop the elements of the planetary gear.
- . It is designed to control the planetary gear.
Normally, automatic transmission provides ease of driving with automatic transmission and maximum comfort. However, during operation, an automatic transmission, like any other mechanism in a car, can fail.
As mentioned above, often transmission failures are manifested by tangible shocks when shifting gears. And also the slipping of the automatic transmission at different stages can fade. At the same time, the complexity of diagnosing a malfunction of an automatic transmission often lies in the necessary complete dismantling of the entire unit.
Signs of slipping automatic transmission
Automatic transmission slippage is manifested by slight slippage when the accelerator pedal is pressed hard or when upshifting. With such slippage, traction disappears, the car engine starts to idle.
If you continue to operate the automatic transmission, ignoring this malfunction, then in the future the slip will increase significantly, the box will begin to slip even when starting from a standstill, as well as when switching the automatic transmission to both a lower and an increased stage.
Why automatic transmission slips: reasons
Slippage when shifting automatic transmission gears to a higher gear often indicates the use of poor-quality or gear oil that has lost its properties. Also in this case it is recommended to check the oil level. Oil should not be below the mark or above.
In this case, the problem is solved by changing the gear oil and air filter automatic transmission. It should be remembered that replacement can only help with a slight slip when shifting automatic transmission gears.
- If the slip occurs only when the automatic transmission is switched to “cold”, then it is necessary to check the friction clutches (friction discs). Friction discs are mounted on a planetary gearbox. When the gear is off, the rotation of the friction rings relative to each other is completely free.
When the gears are engaged, the friction rings, pressing against each other, allow turning the planetary gear (sun gears in a certain order). At the same time, friction clutches are short-lived and wear out over time (with a car run of 200-250 thousand kilometers).
The problem of disruption of the clutches is solved by replacing them. The work of replacing friction rings is quite laborious and complicated, as it requires dismantling, complete disassembly of the gearbox, after which the condition of all moving elements inside the automatic transmission is assessed.
- Hydroblock. Clogged channels of the valve body do not allow for a high-quality supply of ATF to the moving elements. Cleaning of the channels of the hydroblock is carried out by means of cleaning chemistry under the influence of ultrasound.
This work is carried out only on the removed valve body and is very laborious. Also, after repairing the valve body, it is recommended to replace all filters of the car and, accordingly, transmission oil in the automatic transmission.
- If the oil change is completed, but slip occurs when the automatic transmission is switched to “hot”, this means that the solenoid block and / or the pump has failed. As a result of using low-quality or used oil, solenoids become unusable.
To identify this malfunction, the pressure in the lubrication system is measured. If the pressure in the system is at the lowest point, then the problem lies in the solenoids or in the pump.
It is solved by replacing all failed elements, and for a more correct operation of the automatic gearbox, it is recommended to change the solenoids in “packages”. This will ensure their correct operation and reduce the risk of recurrence of this failure.
- Another one of possible causes automatic transmission slipping may be a failure in the electronic control unit (automatic transmission). ECU is a complex electronic device automatic transmission. The control system consists of a memory in which automatic transmission control programs are stored.
The unit also interacts with groups of sensors that provide information about the state of the monitored area at any given time during the operation of the automatic transmission itself, actuators, etc.
To accurately check the automatic transmission ECU and determine the problem, you must contact the service center for high-quality and accurate diagnostics. In the event of a defect, the problem is often solved only by a complete replacement of the automatic transmission electronic control unit, since the device is often unrepairable.
Summing up
If slipping, shocks or jerks began to appear in the automatic transmission while the car was moving, it is necessary to contact the service station for high-quality and accurate diagnostics.
In the first case, the nature of the breakdown is determined on the basis of the readings of diagnostic devices; it is often possible to normalize the operation of the box.
In the second case, in order to determine the degree of complexity of the breakdown, the automatic transmission is dismantled and completely disassembled. These actions are carried out if the cause of slippage of the box can be a malfunction of the valve body or a malfunction of the friction rings of the automatic transmission.
Accordingly, the cost of the repair will depend on the specific breakdown of the automatic transmission and the total amount of work. It is important to remember, however, that even simple replacement oils and oil filter in the machine is a rather laborious and costly procedure. For this reason, you need to clarify in advance how much it costs to change the oil in the automatic box.
Checking the oil level in an automatic transmission: how to check the ATF level. What else to look for: color, smell, ATP contamination, etc. 
The slippage of the drive wheels in snow, mud can have a detrimental effect on the life of an automatic transmission. Let's see if it is possible to slip on the machine without harming the transmission. Be sure to consider the features of off-road driving in a car with an automatic transmission of a torque converter type, a CVT and a robotic gearbox (DSG, Power Shift).
AUTOMATIC AND OFF-ROAD
For a better understanding of the negative factors affecting the automatic transmission in snow and mud, we recommend that you read the article "Automatic gearbox: device and principle of operation."
Due to the greatest distribution, the question: is it possible to slip on the machine, most often arises among car owners with a torque converter type automatic transmission. What consequences can be expected if skidding in snow, mud and off-road driving without following the recommendations?
OPERATION OF THE AUTOMATIC GEARBOX AT THE TIME OF SLIP
In situations where the drive wheels are slipping in mud or snow, switching is the greatest danger to the gearbox. The electronic transmission control unit changes gear ratios based on speed and engine load. The ECU focuses exclusively on sensor equipment (TPDZ, DMRV, gas pedal position sensor, speed sensor). Therefore, when the wheels spin, the ECU “thinks” that the car is accelerating normally and shifts up.
It is the gear change during slippage that leads to increased loads on the torque converter and clutch packs. A similar damage to the automatic transmission is caused by a sharp change in the coefficient of adhesion to the road at the moment of slipping of the drive axle. For example, when the car is slipping in the snow, and then the wheels hit the paved area with good grip.
No less dangerous for the automatic transmission is overheating. The difference in the angular velocities of the turbine and pump wheels of the torque converter leads to intense heating of the working fluid. If the car slips in mud or snow until the moment of forced blocking of the main engine, the volume of oil circulating through the torque converter increases, which leads to an increase in temperature. With excessive heating, the oil cokes in the channels of the valve body and loses its performance. Therefore, frequent off-road use of a car requires a reduction in ATF fluid change intervals.
You can learn about other features of the automatic transmission from the article “How not to damage the automatic transmission when towing”.
HOW TO RIDE CORRECTLY?
CARS WITH DSG AND CVTs
As you understand, it is possible to slip on the machine without harm to the transmission. Perhaps this is due to the principle of operation of the hydrotransformer. While slipping, the main engine smooths out shock loads. If the variator device assumes the presence of a torque converter, then the car will endure trips on light off-road much more calmly. But at the same time, it is possible to slip only until the main engine is blocked. In general, you need to work carefully with the gas pedal to minimize increased loads on the belt and variator cones.
Flaw DSG devices just in the absence of a torque converter. Therefore, the clutch packs used in "wet" DSGs, as well as the clutch discs of "dry" robotic gearboxes on off-road, experience increased loads.