The content of the article:
- What does the automatic transmission consist of?
- Electronic system "machine"
- Hydraulics
- Possible automatic transmission malfunctions
- What is important to know when using automatic transmission
- Pros and cons
- Service nuances
Nowadays, many foreign cars that feel great on the roads of our country are equipped with automatic transmissions. Female owners give preference to such cars. The majority of men, accustomed to "mechanics", do not like an automatic transmission, let's say. But since the passion for foreign-made cars in our country does not subside, but grows, you have to get used to the "automatic", since most of the foreign cars exported to Russia come with automatic transmission.
With proper care, an automatic transmission will last for years. Drivers of such cars always feel confident and calm while driving. All they need to do is press the gas and brake pedal, and the automatic transmission will do the rest.
Automatic transmission device and operation of its components
The following mechanisms are involved in the operation of an automatic transmission:
- Torque converter;
- Planetary reductor;
- Electronic control system;
- Hydraulic control system.
The purpose of a torque converter is to transfer and convert torque from the engine to the transmission. It is placed in a separate housing, where in a special working fluid the mechanisms of the turbine, reactor and pump wheels, freewheel and lock-up clutches work harmoniously. The torque converter operates in a closed loop system.
The principle of operation of the planetary gearbox of an automatic transmission is very difficult to understand for a simple car owner, especially a woman. We will be sure that specialists are well versed in this. It is enough for us to know that this device is quite compact and prevents sharp points and jerks when switching speeds.
Electronic automatic transmission system
All automatic transmissions are electronically controlled, which consists of the following parts:
- distribution module;
- electronic control unit;
- input sensors;
- selector levers.
Input sensors read data on oil temperature, gearbox output and input speed, selector lever position and accelerator pedal. This important information is processed by the electronic control system. The electronic unit is responsible for the moments of switching on the high or low gear. The motor control system and the electronic unit are interconnected.
Hydraulic system
The hydraulic system of an automatic transmission is a very important element that is responsible for the operation of the brakes and friction clutches, as well as the distribution of oil flows (ATF). It is also called the valve body. It is this mechanism that most often fails and leads to the repair of the automatic transmission.
Oil is poured into the gearbox, which moves through special channels. ATF is circulated by a special pump, which is powered by a torque converter. The oil flows in modern automatic transmissions are electronically controlled. The oil is cooled by a separate radiator or heat exchanger.
This is how an automatic transmission works from the point of view of a simple motorist. And even if you are not a supporter of such a technique, you need to know some points - what if you are asked to get behind the wheel by a sick woman or a slightly drunk comrade.
Like all mechanisms sooner or later fail, the automatic transmission is not insured against breakdowns.
What are the automatic transmission malfunctions
Increased oil consumption, jerks and jerks at the time of gear shifting, loss of gear are, perhaps, the very first symptoms of an automatic transmission malfunction. The electronic system will tell you about these malfunctions by turning on the emergency mode. The ECU will engage the transmission protection, and you can safely reach the nearest service station.
Also, regular clutch packages often fail. Experts advise you to immediately change them to more reliable and strong ones made of composite materials. If any defect occurs, you must contact a specialist. They will carry out comprehensive testing, which includes a test drive, visual inspection and computer scanning, and identify any possible breakdowns.
The nuances of using the "machine"
When buying a used car with an automatic transmission, the first thing to consider is the vehicle's mileage. During normal operation, the automatic transmission fails after 80-100 thousand kilometers. If the mileage of the car is more than 100 thousand, then the gearbox has been repaired. This is easy to find out by taking a good look at the junction of the box with the engine and the box itself. Almost all masters say that it is better to replace an automatic transmission with a new one than to give it back for repair. Not only does the repair cost a lot of money, such a gearbox will not last long after it.
Also, experts advise not to expose the automatic transmission to overheating, which leads to the failure of the gaskets and oil seals first, then oil leaks and deformation of metal parts. All this ultimately leads to a breakdown of the transmission itself.
But at the same time, remember that driving a car with an automatic transmission must be started with warmed up oil in the gearbox. Start the engine, press the brake and, holding for 20-30 seconds at each position of the lever, go through all the positions of the wings in all modes. And the moment of overheating of the transmission is also important. When standing in traffic jams, shift the gearbox to neutral and do not keep your foot on the brake pedal for more than 1 minute.
There is another reason why an automatic transmission fails faster than we would like - it is towing a faulty vehicle. Try to get away from this and call a tow truck - it will cost you less than repairing the "machine". Starting a car with automatic transmission from a "pusher" is permissible only as a last resort, but it is better to avoid such techniques.
Advantages and disadvantages of automatic transmission
An automatic transmission is one of the most complex units of a modern car. Like all other devices, automatic transmission has its own advantages and disadvantages. The benefits include:
- The comfort that the driver gets from the trip;
- Automatic transmission prolongs the life of the car engine.
Disadvantages:
- Relatively low efficiency rate than a manual transmission;
- Low dynamic performance, however, in old cars.
Features of servicing an automatic transmission
The main feature of automatic transmission maintenance is the timely check of the oil level in the gearbox, its change and replacement of the oil filter. Under normal operating conditions, the filter and oil should be changed after 50-60 thousand kilometers. If the car works in more difficult conditions, this process should be done after 30-40 thousand kilometers.
In this case, the oil level must be checked more often. A low oil level is not permissible, since the operation of the gearbox depends on its pressure. At a low level, slipping occurs, and this leads to overheating. A low oil level is indicated by a hum from the torque converter. An overstated level is also unacceptable for an automatic transmission - in this case, the oil loses its quality and can lead to a rapid failure of the entire mechanism.The oil level is checked using a special dipstick with markings.
The oil should be poured slowly so that it can fill all cavities. Make a test drive for a distance of no more than 10 kilometers, place the car on a level surface and check the level again. You will have to either add oil or drain the excess.
It is also necessary to know that all oil is never drained from the automatic transmission due to its design features. Typically, 20-40% of the waste liquid remains. Therefore, a complete oil change can be achieved in 2-3 times.
For automatic transmissions, use ATF (Automatic Transmission Fluid). Try to change the oil of the same brand for automatic transmissions or with the same certificate. If you add oil of a different mark, the gearbox is guaranteed to fail very quickly.
