About the automatic transmission, FAQ, what spoils the automatic transmission and other useful information ...
Section of the eight-step automatic gearbox ZF 8HP70.
Automatic transmission (automatic transmission, automatic transmission, automatic transmission change gear) is a type of vehicle transmission that provides an automatic (without direct driver participation) choice according to the current driving conditions of the gear ratio, depending on many factors.
Automatic transmission - how does it work?
The share of AKP in the sales of models of bestsellers.
I advise everyone to read it, there is a lot of useful ...
Constant use of the sports mode automatic transmission will not hurt, it will rather damage your pocket (fuel consumption increases up to 30%).
Some aspects of automatic transmission
1. Sport mode as such during normal driving does not lead to any special wear of both the box and the engine.
2. The machine accelerates from 0 to 200, for example, equally fast, regardless of whether the so-called so-called speed is activated. "sport mode" or not.
3. The fuel consumption, strangely enough, very slightly depends on that, in the third gear to go with speed. 100 km / h or on the 4th.
4. Do not destroy the box "sports", but:
b) Switching when "gas in the floor"
c) Switching "down" when the speed is high
d) Low or high oil level
e) Sharp driving on a superheated box
f) Riding in "borderline" modes between transfers on boxes where the "hysteresis" is small
g) Ride with very frequent switching
g) "gambling" with the gas pedal (Among the "professional drivers" who have been driving carburettors all their life, there is a bad habit - when starting from a place to give gas not exactly, but impulsively, adding and releasing gas 4-7 times a second. Do and before the overtaking, for example.Why so - separate conversation, but on the automatic transmission it does not affect positively.
In all hydromechanical automatic transmissions there is a strict dependence of the number of the included gear not only on speed, and on engine speed, but also on the position of the "gas" pedal. Therefore, when the pedal position changes at a constant speed and speed, if the difference in pedal coordinates exceeds the hysteresis imposed by the designers
when designing the box, the box switches up-and-down-up ... Of the latest models, this behavior has seen the Mersov-puff-eyed little-car automata)
h) "gas supply" during "up" switching
i) a sharp "discharge of gas" at the moment of switching "down"
d) constant driving with "slips"
j) the inclusion of reverse gear at a speed of more than + 1 to 2 km / h
l) the inclusion of forward modes at a speed of more than [minus1-2] km / h
m) switching front / rear with increased engine speed (> 1000-1200 depending on the type of box)
m) riding on a warm box at all temperatures (The meaning of "warming up" even at +25 is not the heating itself, but:
- 1. Pumping oil to remove bubbles from the areas where they should not be.
- 2. Washing out unnecessary harmful all sorts of particles from the friction pairs, which there "sat down" from the previous trip, and the pressure of the heated oil was not enough to "wash" them.
- 3. Pumping of oil to sharp decrease of its viscosity to the working one. Oil at the same temperature has a different viscosity, depending on the "prehistory". Well, like a sour cream, only a smaller effect - when there are several hours - it thickens strongly. Stir - it's liquid again.)
o) towing vehicles with automatic transmission over long distances
n) Towing the car with automatic transmission at high speed
p) simultaneous use of the "gas" and brake pedals
c) the operation of the automatic transmission together with the "triple" motor
t) the operation of the automatic transmission together with the "crunchy" CV joints
y) frequent touching on higher gears (on boxes, which in principle allow it)
f) a long ride on the automatic transmission, located in the "protected modes"
x) further driving on an obviously faulty box
c) at the start of the gas supply BEFORE the machine has received a tangible push forward as a result of turning on the gear
h) "pushing" switching with the aid of adding gas with a pedal
w) riding a poor quality old oil
ny) driving with frequent locks / unlocking of the hydrotransport (on the automatic transmission, where it is)
е) riding on oil that does not match the manual (dexron instead of dexron-II, for example)
s) sudden gas supply after braking by the engine with forced lower gear
ь) driving with an overheated motor
e) a sharp ride on a freshly repaired automatic transmission
ю) fast sharp driving backwards
i) driving on my own business, when I have to go to the service.
Frequently asked questions about automatic transmission
1. How to check the oil level in the automatic transmission?
For most vehicles, the oil level (ATF) in the automatic gearbox (automatic gearbox) is checked with the engine running and setting the range select lever (ROV) to the "P" position. On the dipstick for measuring oil in the automatic transmission, as a rule, there are several marks. The two upper, and sometimes the only ones, correspond to the normal level of the oil heated to operating temperature (90 ° C). Often this part of the probe is marked with a notch and / or the inscription "Hot". In order for the oil in the automatic transmission to warm up to the operating temperature, it is necessary to travel 15-20 kilometers. After warming up the oil in the automatic transmission, place the vehicle on a level, level platform. Pull out the dipstick from the automatic transmission, and wipe it dry. Then insert the dipstick back into the dipstick tube as far as it will go and then remove it again. The lowest, dry place on the dipstick and will correspond to the oil level in the automatic transmission. Sometimes on the dipstick there are also lower marks corresponding to the level of the cold one. This label is intended to approximate the amount of oil that has been filled in when it is replaced. Finally, the level, anyway, should be checked after warming up the oil. Often on the dipstick it is written in which position of the RVD should check the level and type of oil used. There is also a special case - cars Honda and Acura. They check the oil level as soon as the temperature reaches the operating temperature, but with the engine stopped. There are automatic transmissions in which the oil level is checked when the RVD is installed in the "N" position. Such gearboxes are used on front-wheel drive cars Mitsubishi, Proton and Hyundai. Note, it's not about the models of cars, but about the models of transmissions. For example, front-drive boxes and Mitsubishi can be found on Chrysler cars and vice versa. If you have a car Proton or Hyundai, then the oil level in the automatic transmission should be checked in the position of the RVD "N". In the case of a Mitsubishi or Chrysler car with a transverse engine arrangement, look at the automatic transmission from the side of the wheel. If there is a side stamped cover fixed with ten bolts, then you have an automatic transmission manufactured by Chrysler, and an oil level check should be carried out when installing the HPH in the "P" position. The absence of such a cover indicates that your car is equipped with automatic transmission of Mitsubishi, and the oil level should be checked when installing the RVD in the "N" position. Also in the "N" RVD position is checked level on cars Jeep Cherokee and Jeep Grand Cherokee with automatic transmission manufactured by Chrysler. But on some models of these cars there are automatic transmissions of firm Aisin Warner, in which the oil level should be checked in position РВД "P". To determine the type of box installed on your car, you can use the following method. Automatic transmission of Aisin Warner has a tray of rectangular shape, the feeler tube is welded directly to the pallet on the side, and in the back part of the pallet there is a drain plug. Chrysler automatic boxes have almost a square pallet, the feeler pipe is installed in the crankcase of the box and there is no drain plug. In addition, check the oil level in the automatic transmission of cars VW, Audi with three-speed boxes should be carried out when installing the RVD in the "N" position. In some automatic transmissions, instead of a feeler in the crankcase, there is a control plug. Not convenience of this is that to check the oil you need to put the car on a "pit" or lift on the lift. But there is an advantage: you will never pour oil in the automatic transmission, which is very important. Such plugs have automatic transmissions of firm ZF, which, as a rule, are equipped with BMW cars. And on a BMW with five-speed boxes, the same cork also serves to fill the oil. For safety reasons, level control in this case is carried out with slightly warm oil. This is European fashion. On "Americans" such procedure of check of level to us met only in automatic transmission 4T40E. It should be noted that there is an automatic transmission, which, in general, does not provide any devices for determining the oil level. This transmission Mercedes 722.6, which is now installed, in practice, on all cars of this company. The fact that the tank, which is filled with oils for automatic transmission, is connected to the oil pan through the bypass valve, the purpose of which is to maintain the required level of oil in the pan. Therefore, the level of the oil is not as important as for other transmissions.
2. What is dangerous is low or high oil level in the automatic transmission?
Too low ATF level is dangerous because the pump starts to catch air along with the oil. As a result, an air-oil "emulsion" is formed, which is well compressed and has a low heat capacity and thermal conductivity. Oil loses the most important of its properties and becomes compressible. The consequence of this will be a reduction in pressure in the control system, poor heat removal from the automatic transmission, deterioration of lubrication of friction elements. Operation of the vehicle with foamed oil in the automatic transmission will quickly disable the box. I would like to note that one should not confuse individual large bubbles of air in the oil on the dipstick (which sometimes happens) with foaming oil, which is a uniformly foamed liquid with very small air bubbles. Foaming oil increases its volume, so when checking the level it will be too high. In this case, stop the engine and allow the oil to settle for some time, and then, without starting the engine, check the oil level. If the probe turns out to be completely dry, then you can boldly add a liter, or even two. The oil can foam and rotate the parts of the automatic transmission if the level exceeds the allowable value. In this case, the rotating parts of the automatic transmission are dipped in the oil and foamed. Foaming occurs not immediately after starting the engine, as in the case of a low level, but in the process of driving, especially with high engine speeds. As in the case of a low oil level, and in the case of an overestimate level, the foaming of the oil leads to an increase in its volume, and, as a consequence, to its ejection via the gearbox breather. Looking under the car, you can often see there that the whole box is in oil.
Here is a case from practice. Ford Explorer came to the diagnostics with a complaint that something is going on with the level of something incomprehensible. Level - that is, it does not, but the automatic is all in oil. In conversation with the client it was found out that the probe was lost and replaced by a new one, ordered by VIN from the dealer. When comparing the probe and the feeler tube, it turned out that the probe is much shorter than the pipe. The ATF level was just at the level of the axis of the box. (Usually the level is approximately level with the pallet lining). Thus, the client's complaint was caused by a too high level of ATF in the automatic transmission.
3. The level is normal, but ATF foams, what's the reason?
This is possible if the seal of the filter or the filter itself is damaged.
4. The level is constantly lowered, and there are no signs of oil leakage.
The prerequisite for such a malfunction is the presence of a vacuum modulator in some types of automatic transmissions, a special pressure generating device proportional to the degree of vacuum in the intake manifold of the engine. Externally, the vacuum modulator resembles a similar device on the Zhigulevsky trambler. The modulator is connected to the intake manifold by a tube, through which, in the event of a malfunction of the modulator's membrane, the oil from the automatic transmission enters the collector and burns. Typical representatives of cars on which the automatic transmission with the modulator is installed: Ford Scorpio, Ford Sierra, Ford Explorer, Mercedes, front-wheel drive cars of concern General Motors with four-speed automatic transmission. It should be noted that since the beginning of the 1990s, there has been a refusal to use modulators and replacing them with electrical sensors. Another reason for lowering the level of ATF in the automatic transmission in the absence of leakage may be a violation of the tightness of the cooling system. In many cars, the radiator for cooling the automatic transmission oil is built into the cooling cooler of the engine antifreeze. If there is a breach of the tightness of the built-in radiator, the oil gets into the engine cooling system, as a result of which the antifreeze turns into a pinkish emulsion.
5. How much oil should I fill in the automatic transmission?
Depending on the type, the automatic transmission can accommodate from 4.2 liters (DAIHATSU TERIOS) to 15.5 liters ATF (FORD EXPEDITION). It must be borne in mind that when replacing, not all of the oil is drained. Part of the oil remains in the channels of the control system, and, in addition, not all transformers have plugs for draining oil from them. Therefore, when draining the oil, part of it remains in the automatic transmission, but this is considered acceptable. If you want to completely change the oil, then you need two or three-time oil change.
6. How can I determine what is in the automatic transmission and what oil should I fill in when replacing it?
Transmission oils differ in both color and odor. There are light yellow oils, and there are red shades (from light CASTROL to saturated red ELF). It should immediately be said that the color of the oil is determined only by the dye, which is added to it so that it is possible to distinguish the oil for automatic transmission from other oils used in the car. More than anything, the color of the oil does not determine. In addition, after a short period of time, any oil acquires a transparent-brown color. Considering that when changing the oil, not all of its volume is updated, and also that the color and smell of the oil change during use - it is practically impossible to determine its brand, even if it has changed recently. It is necessary at least once, and preferably double oil change (in the absence of serious problems in the automatic transmission). Use the oil that is specified in the vehicle's operating instructions. It happens that the type of recommended oil is also indicated on the dipstick. In addition, the manufacturers of oils produce posters and albums (they can be found in specialized stores) with a list of car brands and recommended oils, both motor and transmission. Usually, the instruction manual recommends the use of a certain type of oil. Probably, this is not only a technical, but also a commercial rationale. For example, Chrysler and front-wheel drive Mitsubishi (Hyundai) use Mopar ATF 7176, and the instruction indicates that this oil has increased frictional properties compared to Dexron or Mercon. But on the dipstick of Dodge RAM and Jeep Grand Chrokee, you can find recommendations to fill Mopar ATF 7176 or Dexron II. It means that you can. Another example: Mobil does not recommend mixing different types of oils, even their own production. But the quote from the bottle of Mobil Synthetic ATF: "Compatible with conventional ATF fluids" (Compatible with conventional oils for automatic transmissions). If it concerns the replacement of oil in the engine - the algorithm is simple. We go to a solid store, choose an oil producer (according to one known criterion). From the whole range we choose oil for gasoline or diesel engines, we choose API class oil (not lower than in the operating instructions) and the desired SAE viscosity. All. Why is it that if it concerns transmission, do not we spare the time and money to look for green oil? Not because of the fact that the automatic transmission is more exotic than the engine? The experience of repairing several thousand automatic transmissions says that the causes of breakages are more prosaic than mixing of different types of oils when replacing it. The conditions of transmission operation are of paramount importance, and even the most expensive synthetics will not help if they are violated.
7. How often should I change the oil in the automatic transmission?
The term of oil change depends on the type of automatic transmission, and, usually, under normal operating conditions, it is recommended to change it through 70 thousand kilometers of the car's run (or after 2 years) and after 25 thousand kilometers (or in 1 year) if the operating conditions are different from normal ones (hot climate, cold climate, operation in a metropolis, constant operation of the machine with full load, etc.). At some expensive models (for example, BMW 750) under the instruction replacement of oil in general is not provided. But no matter what, regularly (once a week) check the quality of oil in the automatic transmission of your car. To adhere to the established terms of replacement should be, if during the operation there is no significant change in the quality of oil or you do not fall into difficult traffic conditions (stuck, long towed another car, etc.). In case of darkening of oil and or purchase of a burning smell it is necessary to replace it, without waiting for the planned replacement period. But not always replacing burned oil can save the situation. Most often in these cases, a major overhaul of the automatic transmission is required. When replacing the oil in the automatic transmission, it is also necessary to change the gasket of the pallet and the filter. In some types of automatic transmissions, the filter change during the oil change is not provided, because The filter is not accessible without removing or disassembling the automatic transmission (for example, Daewoo Espero, Nissan Maxima (with RE4F02A box), SAAB 900 and 95, Volvo 850, front-wheel drive Opel models with four-speed automatic transmission). How to evaluate the quality of oil in the automatic transmission? Different types of oils differ in both color and smell. If your box has recently been repaired, remove the dipstick and remember the color and smell of ATF. If the color or smell has changed significantly during operation, then there is an occasion to contact the service to check the status of the automatic transmission. When buying a car with an "automatic", the oil should be transparent and not have a dark brown hue or burnt odor. Drip the oil from the dipstick onto a white paper towel and make sure that the oil is easily absorbed and there are no foreign inclusions in it. If in the faulty automatic transmission before the sale several times in a row the oil changed, then still, with a careful analysis of the drop of oil in it, you can distinguish small black particles that do not harmonize with the transparent and bright oil. Often you can see a black touch on the dipstick. In this case, it is necessary to wipe the dipstick well and re-analyze the oil condition. If the raid did not reappear, then the previous one was a consequence of the fact that the probe was not used for a long time. It does not hurt to look into the engine cooling system and make sure that the antifreeze is transparent and does not contain a water-oil emulsion. Keep in mind that you can find a red antifreeze, at first glance reminiscent of oil for automatic ACPP.
8. What oils are used in the automatic transmission except for automatic transmission oil?
In front-wheel drive automatic transmission designs, as well as in some all-wheel drive transmission configurations (for example, AUDI, SUBARU), the main transmission and the differential are located in the same crankcase with the gearbox. This arrangement is called transaxle, unlike transmission, when the main gear is in the rear axle. If the main pair is in the same body with the automatic transmission and is a hypoid gear, then the oil for hypoid gears is poured into the differential case (separate lubrication). In other cases, the lubricant can be either separate or joint. In the case of helical, helical engagement in the main gear, the oil for ACPP is generally used to lubricate it. Checking the oil level in the differential with joint lubrication is not required. In the case of separate lubrication, as a rule, there is a control plug or a feeler gauge. How to replace the oil in the automatic transmission? The sequence of operations when replacing the oil is the same as for replacing the oil in the engine. We merge the old oil, change the filter, fill in the new oil. In most cases, a pallet is required to replace the filter. Sometimes the filter is inside the automatic transmission and is not accessible without disassembly and disassembly of the automatic transmission. In this case, the oil changes without changing the filter. Together with the filter, the pallet is also changed. Usually, the filter and gasket are sold in one set (Filter kit). On some models, the pallet is placed without laying on the sealant. If the filter is made in the form of a fine metal mesh and is not damaged, then you can leave the old, rinsing and blowing it with compressed air. Before installing the filter in place, check the sealing quality of its seat hole. To tighten bolts of fastening of the filter and the pallet follows strictly certain moments specified in the instruction of operation of the car. After you have filled in fresh oil, it is necessary to start the engine. While holding the car with the brake, move the WFD to all positions, lingering in each for a few seconds. Then set it to "P" or "N", check the oil level and bring it to the mark corresponding to the cold oil condition. Finally check the level only after a run of 15-20 kilometers, when the oil temperature reaches the operating value. During the oil change, it is necessary to evaluate the presence of wear products in the pallet, on the pallet magnets and in the filter. A small amount of suspended matter in oil, dust of non-ferrous metals and a small gray coating on magnets can be considered the norm. Pieces of plastics, metals, the presence of black scales or clay-like deposits in the pallet indicate the need for a thorough overhaul of the automatic transmission, even if complaints about the operation of the transmission are not yet available.
Modern oils already have all the necessary additives in their composition. This question is often asked if there are problems in the operation of the automatic transmission. In most cases, problems in the operation of automatic transmission are accompanied by increased wear of friction control elements. This is an irreversible process and neither oil change nor additives will restore them. Therefore, by and large, overhaul is the only way to restore the efficiency of the transmission.
10. What do the range lever selection symbols mean and why are they needed?
The range selection lever (HFM) of the gearbox has several positions that have an alphabetic and numerical designation. The number of these positions for different models of cars is different, but on all cars the WFD necessarily has the positions indicated by the letters "P", "R" and "N". Position "P" Select when the vehicle is parked for a long time. In this position of the ROV in the automatic transmission, all controls are turned off, and its output shaft is locked, so the car can not move. This mode allows the engine to start. Position "R Reverse: Moving the lever to the" R "position during driving can damage the transmission and other transmission components, and the engine can not be started in position" N "position. In the gearbox, or only one is turned on.The mechanism for blocking the output shaft is turned off, ie, the car can move freely.In this mode, the engine is allowed.For cars equipped with four-speed transmissions, the RVD band has, as a rule, four (D), "3", "2" and "1" ("L") It should be noted that if the RVD is set to one of these positions, the engine can not be started. The "D" range is the main mode It provides automatic switching from the first to the fourth gear.In the normal driving conditions it is recommended to use it.The range of "3" - you can drive on the first three gears.It is recommended to use when driving on a hilly road or in conditions of frequent stops. Range "2" - you can move only in the first and second gears. Recommended for use on winding mountain roads. Switching to the third and fourth gear is prohibited. Range "1" - you can move only in the first gear. This range allows maximum implementation of the braking mode by the engine. It is recommended when driving on steep slopes. On some models of cars permission to use the fourth, boost, transfer is carried out with the help of a special button "OD". If it is in the recessed state and the RVD is set to the "D" position, it is possible to switch to upshift. Otherwise, the inclusion of the fourth upshift is prohibited. The status of the control system in this case is reflected by the "O / D OFF" indicator. In the case of allowing the use of upshift, the indicator does not light, and lights up when prohibited.
11. Why do I need additional buttons (switches)? What is the winter regime?
On most modern cars with automatic transmission, the control system has several options for controlling the gear shift. These include - economical, sports, winter, etc. An economical program. The program is configured to provide traffic with minimum fuel consumption. The movement of the car in this case is smooth, calm. Sport program. This program is configured to maximize the use of engine power. The car in this case develops, in comparison with the economical program, significantly greater acceleration. To implement an economical or sporty program on the dashboard or next to the range selector there is a special button or switch that can be labeled "POWER", "S", "SPORT", "AUTO", "A / T MODE "and the like. Electronic control units of almost all modern cars have a special program of starting from a place on a slippery road (winter program). To activate it, there is also a special button or switch that can have the notation "WINTER", "W", "HOLD", "*", etc. In the case of its operation, various algorithms of automatic transmission work are possible, but, as a rule, in all cases, starting is carried out either from the second or from the third gear.
12. What is overdrive? Which of the modes is preferable in urban driving conditions or overdrive?
Overdrive in the terminology of American automakers means boosting transmission. It is usually denoted as "OD", or D, or D in a circle. It is recommended to use an overdrive for a measured, economical ride on the highway.
13. Can I toggle the range selector on the fly?
It is possible, but not in all positions. It is strictly forbidden to move the WFD to positions "P" and "R" when moving forward. In both these positions, the lever can only be transferred when the car is completely stopped. Violation of this rule can lead to a serious breakdown of the automatic transmission. In addition, it is not recommended to move the WFD to the "N" position during the movement, since in this case the communication of the wheels with the engine is lost and sudden braking can cause the vehicle to drift. And in all the other provisions of the WFD can safely translate. In some cases, it is even recommended to do it on purpose. So transferring the ROV from position "3" to "2" will increase the efficiency of engine braking, etc.
14. Should the range selector switch to "N" when stopping at a traffic light?
It makes sense only for long stops in street traffic jams in hot weather, to reduce heat generation and prevent overheating of the oil box. In other cases, this is not even recommended.
15. Do I have to use the parking brake in the parking lot if the range selector is in the "P" position?
For reliable fixation of the car in the parking lot on relatively even areas of the faulty mechanism of blocking the output shaft of the automatic transmission is enough. But if the car is on a slope, then the manual brake is mandatory. And the first thing is to tighten the handbrake and only after that to establish the RVD in the "P" position. In this case, you release from the additional load associated with the desire of the car to slide down, the mechanism of blocking the output shaft of the automatic transmission.
16. How to determine the number of transfers in the automatic transmission?
In Japanese cars, the four-speed automatic transmission can be identified by an additional button on the ROV, which is marked "OD OFF", or "Hold". If there is no such button, then, most likely, the automatic transmission is three-speed without an overdrive. In European cars, the three-speed automatic range selection lever is marked with PRND21 symbols. Four-speed - PRND3. Five-speed - PRND4? In American cars, the symbol D in the circle indicates the presence of the fourth (sometimes fifth) upshift. Having some experience, you can determine the number of gears in practice, following the arrow of the tachometer during the acceleration of the car. Each switching will be accompanied by a certain decrease in engine speed. Only in this case, it must be borne in mind that the tachometer needle reacts in the same way to the lock-up of the torque converter (although, the speed drop in this case will not be as noticeable as during the gearshift).
17. Is it possible to slip on the car with automatic transmission?
Nothing criminal during slipping in the automatic transmission does not happen. The increased heat dissipation in the torque converter in this case can be critical if the cooling system is of low efficiency (the cooling cooler of the automatic transmission is clogged by the wear products).
18. How do I tow a car with automatic transmission?
In this issue, too, there is no single answer. For some cars there are very strict passport restrictions. For example, the Jeep Grand Cherokee is recommended to be transported only on the tow truck. A little easier with Chrysler's front-wheel drive. Cars with a three-speed automatic transmission can be towed at a speed of 40 km / h for a distance of 25 km, and with a four-speed automatic transmission - at a speed of 72 km / h for a distance of up to 160 km. And yet, no matter what machine it is, in the case of a faulty transmission, a tow truck is preferable. The fact is that in the automatic gearbox lubrication is forced, i.e. The oil is supplied to each pair of friction under pressure. If the transmission is faulty, then there is no certainty of the presence of lubricant. However, indirectly, the performance of the pump can be estimated. It is necessary to compare the oil level when the engine is muffled and running. If the level does not change, do not even think about towing. Towing is carried out when the engine is running and the RVD is set to the "N" position. There is another way to tow a car with a failed automatic transmission. Pour the maximum in the automatic transmission oil, which will provide at least some kind of lubrication of all its parts.
19. Is the trailer towed by a vehicle equipped with automatic transmission?
Allowed. But we must remember that the higher the load, the greater the heat release in the hydrotransfomator. If you are constantly using the trailer, consider installing an additional radiator in the automatic transmission cooling system. In addition, in the case of prolonged towing of the trailer, the use of an upshift is undesirable. It is better to do this on the bands "3" or "2".
20. Do I have to warm up the automatic gearbox before starting the journey?
The first time after the beginning of the movement, it is recommended to avoid dynamic driving, until the oil in all units has warmed up to operating temperature. In the cold season, before the movement begins, it will not hurt to warm up the oil in the automatic transmission a little. For this, it is necessary to move the WFD to all positions, lingering in each of them for a few seconds. Then, turn on one of the driving ranges, and hold the car for a few minutes with the brake, the engine must be at idle speed.
21. What are the main advantages and disadvantages of the automatic transmission system?
Automatic transmission increases the comfort of driving. The absence of the need to choose the right gear and the implementation of gear shifting, allows you to focus on driving, which in a difficult traffic situation will not prevent even the experienced driver. Due to the torque converter, the automatic transmission creates more favorable operating conditions for both the engine and the chassis, which increases their life, and the automatic transmission control system prevents overloads of the engine and undercarriage due to driver errors. The car with automatic transmission is equipped with a system of passive safety, which does not allow to start the engine in the RVD positions other than "P" and "N". And also prevents the spontaneous movement of the car when parking on an uneven site, because It is only possible to remove the key from the ignition switch in the "P" position. The disadvantages of automatic transmission should include a lower efficiency (due to losses in the torque converter) than the mechanical transmission, which increases fuel consumption. Although this is not always the case. Modern automatic transmissions in some driving modes allow to achieve higher profitability in comparison with mechanical gearboxes due to maintenance of optimum engine revolutions and "intelligent" control of the lock-up of the torque converter. Another disadvantage is the somewhat worse dynamic parameters of the acceleration of the car with automatic transmission than with the mechanical transmission, all other things being equal. The difference is not so great and for the bulk of drivers is insignificant. And, finally, the car with automatic transmission can not be started otherwise than with the help of a starter. It should be noted that the vast majority of drivers with experience in both types of transmissions, regardless of their level of prosperity and driving experience, give unconditional preference to cars with automatic transmissions.
22. What is a kickdown?
If the throttle control pedal is pressed all the way into the stop, the gearbox will switch to one or two gears down. This mode is recommended to use to obtain higher acceleration values, which is useful, for example, during overtaking. The reverse upshift in this case can occur only when the engine reaches its maximum speed. If you release the throttle pedal, the gearbox will go into normal operation. It should be borne in mind that on a slippery road during a forced lowering of the transmission, the driving wheels may begin to slip, which can lead to skidding.
23. What does the automatic transmission cooling system look like?
As already noted, the main source of heat in the automatic transmission is a torque converter. And at high loads, heat release is large enough. The operating temperature of the transmission is comparable with the temperature of the engine, and may exceed it. Therefore, cars with automatic transmission have a special cooling system, the radiator of which is either integrated in the radiator of the engine cooling system, or installed separately and cooled by air flow. On older cars with a small engine volume, you can find boxes that have an air cooling system. On the body of the torque converter there are additional external vanes, with the help of which the air flow for heat dissipation is organized.
24. How to start the car with automatic transmission?
Before the start of the movement, you should always press the brake pedal, move the ROV to the desired position, without pressing the throttle control pedal. After a slight push, you can release the brake pedal and start the movement by acting on the throttle control pedal.
25. What are the available methods for checking the status of automatic transmissions? What is "Stall-Test"?
First, check the level and quality of oil in automatic transmission. Secondly, the turn-on time of the transfer when moving the RVD from "N" to "D" or "R" should not significantly exceed 1 - 1.5 seconds. On the inclusion of the transfer can be judged by the characteristic thrust. Pay attention to the quality of switching during run-in. When changing gears, there should be no "bumps", no vibrations, and no noise. The gear shift must not be accompanied by an increase in engine speed. An experienced driver on the behavior of the machine on the road can make a qualified preliminary conclusion about the state of the automatic transmission. For your information: Tahoe-Transmitting provides free services - running a car by an experienced driver (test drive), reading trouble codes and consulting. Another simple method of checking the state of automatic transmission is Stall-Test. The essence of this test is to determine the engine speed with a fully braked car and the throttle control pedal depressed until it stops. By the magnitude of these revolutions, one can judge the serviceability of certain elements of automatic transmission. Immediately make the reservation that the Stall-Test should be performed by an experienced mechanic. Otherwise, you yourself can disable the automatic transmission. In addition, to analyze the performance of the automatic transmission, it is necessary to know the nominal value of the engine speed during the Stall-Test, without knowledge of which this test will not give you anything.
26. Can I do without repairing the automatic transmission, if the car sometimes does not go?
Owners of cars with "electronic" automatic transmissions in the absence of traffic hope that all problems are in the failed sensors, after the replacement of which everything will be fine. Problems with sensors may be, but as they say: "Late to drink Borjomi?". The fact is that control algorithms do not provide for blocking traffic in the event of any failures in the system. Even if the automatic transmission does not tear off all wires and sensors, the car will not lose the ability to move. There will be no good dynamics and gear changes, but you can go. The lack of movement forward, or backward, even periodic, indicates serious problems already in the mechanical part of the automatic transmission, and only one way out is repair. Sometimes you can hear the statement that the cause of all the troubles can be a clogged oil filter in the automatic transmission. Like, replace the filter, replace the oil twice - and all problems will disappear. This does not happen. The process of destruction of friction elements is irreversible. Burned frictions are treated only by replacing them, the new oil can not repair them.
27. What is the difference between "hydraulic" and "electronic" automatic transmission?
The automatic transmissions are the same in the first case, and in the second. The main difference concerns the management system. The control system can be conditionally divided into three parts: generating signals of the state of the automatic transmission and its control; analyzing and executive. In the case of a "hydraulic" automatic transmission, the operability of all these three parts ensures hydraulics by forming the appropriate pressures. In the case of an electronic automatic transmission, all signals (input and output) are electrically generated, and only at the end of the control signal chain is hydraulics used. In addition, an electronic control unit (computer) is used to analyze incoming information and make a decision. This allows you to make the automatic transmission control system more flexible, providing modes of automatic transmission that are inaccessible to the hydraulic control system.
28. What are codes? Why does the "OD OFF", "Hold", "S" or "Check AT" lamp flash? Why there are no gear changes?
Здесь речь пойдет об автоматических коробках с электронной системой управления. Работой "электронных" АКПП управляет бортовой трансмиссионный компьютер, который может быть выполнен как в виде отдельного устройства, так и быть совмещен с блоком управления двигателем. В трансмиссионный компьютер поступают сигналы различных датчиков (скорости, угла открытия дроссельной заслонки, положения РВД, температуры масла АКПП и т.д.), расположенных как в АКПП, так и вне ее. Он обрабатывает эту информацию и на основе ее анализа вырабатывает команды (выходные сигналы) исполнительным устройствам в АКПП (соленоидам). Таким образом происходит управление работой автоматической коробкой передач. Компьютер выполняет также и другую функцию - контроля и диагностики неисправностей. Для всех входных сигналов есть допустимые границы их изменения. Если какой- либо сигнал выходит за допустимые пределы, то компьютер записывает в память некоторую последовательность цифр - код (Diagnostic Trouble Code - DTC), соответствующий данной неисправности. Кроме того, компьютер контролирует сопротивления выходных цепей (либо токи, протекающие по ним, что одно и тоже). Для них тоже существуют допустимые границы, при выходе за которые в память записывается соответствующий код неисправности. Кроме того, компьютер может сравнивать показания датчиков оборотов входного и выходного вала АКПП, тем самым контролировать передаточное отношение АКПП. Отклонения вычисленного передаточного отношения от заданного является признаком проскальзывания во фрикционных элементах управления АКПП, что также фиксируется соответствующими кодами в памяти трансмиссионного компьютера. К сожалению, функция контроля передаточных отношений реализована далеко не во всех моделях автомобилей. Для чтения кодов в памяти компьютера требуется специальное диагностическое оборудование - сканер. Сканер позволяет не только считывать коды, но и стирать их, а также с его помощью можно определить показания различных датчиков системы управления АКПП. Процедуру считывания и определения неисправностей по кодам часто называют компьютерной диагностикой. Что произойдет после того, как в памяти трансмиссионного компьютера появится код неисправности? Это определяется алгоритмом программы, по которой работает компьютер. Реакция управляющей системы неоднозначна. При появлении одних кодов никаких ощутимых изменений в работе трансмиссии не произойдет, а другие коды могут вызвать отсутствие переключений передач. Все зависит от того, в каком контуре системы управления произошел сбой. Одни коды носят информационный характер (например, код "отсоединялась аккумуляторная батарея"), а другие приводят к изменению алгоритма работы системы управления АКПП (например, код "обрыв в цепи соленоида"). В случае возникновения серьезных проблем система управления переходит в режим защиты АКПП. У этого аварийного режима есть разные названия: Limp In, Limp Home, Safe Mode и т.п. Алгоритмы работы системы управления в аварийном режиме во многом определяется моделью АКПП. В некоторых случаях система управления перестает отслеживать качество переключений, и они происходят с "ударами". В других случаях в коробке включается вторая или третья передача, и все переключения передач запрещены. В некоторых автомобилях аварийный режим сопровождается миганием, либо постоянной индикацией на панели приборов одного из сигналов, связанных с работой АКПП: "Hold", "S", "Check AT", "OD OFF" и т.п. В случае совмещенного моторно-трансмиссионного компьютера этим сигналом может быть "Check Engine", либо символ в виде контура двигателя. Если ни один из этих сигналов на панели не светиться, то это не означает отсутствие в памяти компьютера кодов неисправностей, но если сигнал есть, то есть и коды в памяти компьютера. Аварийный режим не предполагает эксплуатации автомобиля, он служит только для того, чтобы добраться до сервиса и устранить неисправность. Если этого не сделать, то может получиться так, что из-за незначительной, вовремя не устраненной неисправности, выходит из вся АКПП. Надо иметь в виду, что "электронная" коробка, по сути - исполнительное устройство. Проблемы с переключениями передач, плохая динамика, рывки, "удары" могут быть обусловлены как неисправностью самой трансмиссии, так и проблемами с проводкой и датчиками, а также неисправным трансмиссионным компьютером. Проблемы в бортовой электронике приводят к выходу из строя самой коробки, после ремонта которой ситуация наверняка повторится. И так до тех пор, пока не будет устранена причина неисправности электронной части системы управления, которая не всегда находится в самой АКПП. Как правило, автомобили, поступающие в ремонт, имеют не одну, а целый комплекс неисправностей. Разобраться в этом клубке проблем поможет квалифицированная диагностика. Но не следует ожидать от диагностики чудес, хотя иногда удается быстро устранить проблему и коробка на глазах "оживает". Возможности диагностики имеют объективные ограничения. Компьютерная диагностика далеко не равнозначна для разных типов АКПП. Ее возможности можно оценить, взглянув на полный список кодов для данной модели АКПП. У одних моделей список всех возможных кодов (а значит и контролируемых параметров) состоит из четырех пунктов, а других насчитывает полсотни.
29. Что такое адаптивные автоматические коробки передач?
Опять таки, этот термин больше относится к системе управления, а не к самой АКПП. Развитие "электронных" АКПП привело к появлению адаптивных коробок передач. Разрабатываемые алгоритмы управления становятся все более интеллектуальными, что приводит к появления нового качества в тех же самых, с механической точки зрения, трансмиссиях. Бортовой компьютер следит за манерой водителя управлять автомобилем, подстраиваясь соответствующим образом под нее. Кроме того, в алгоритм работы такого компьютера заложен учет износа в АКПП фрикционных элементов управления. Все это приводит не только к повышению комфортности поездки на автомобиле, но и к повышению его ресурса и экономичности.
30. Что такое Autostick (Steptronic, Tiptronic)?
Это система управления работой АКПП, в которой на ряду с автоматическим, предусмотрен и полуавтоматический режим управления, при котором команду на переключение передачи дает водитель, а качество этих переключений обеспечивает система управления. В зависимости от производителя этот режим имеет разные названия (Autostick, Steptronic, Tiptronic), реализуется он только на автомобилях, имеющих электронную систему управления АКПП, и то не на всех. В автомобилях оборудованных такой системой, РВД имеет специальное положение, в котором включается режим Autostick. Относительно этого положения есть два противоположных, не фиксируемых положения РВД. Эти положения имеют обозначения "+"("Up") и "-"("Dn"), соответственно для переключения на более высокую или более низкую передачу. Режим Autostick является скорее полуавтоматическим, чем ручным, т.к. трансмиссионный компьютер, не перестает контролировать действия водителя и не позволит ему, например, тронуться с высшей передачи, или выбрать передачу таким образом, чтобы обороты двигателя превысили допустимые. В остальном же, полная иллюзия механической трансмиссии. По желанию водителя можно перейти и на обычный автоматический режим управления, переведя РВД в положение "D".
So that's it. АКПП, работают отлично и крайне надежны во все времена года, кроме зимы. Поэтому рассказываю, как не засадить АКПП если температура ниже 15 град.
1) Надо греть машину до РАБОЧЕЙ! температуры. Маслянный радиатор коробки и двигла один и тот же, а коробка от двигла дальше, поэтому АКПП прогревается ПОЗЖЕ.
2) Если уж очень не втерпеж, догреть хотя бы до 40, а потом на ходу, включив 3 передачу и на скорости не более 40 км/ч до рабочей.
3)Перед зимой смените масло и фильтр. Азбучная истина - но результат отнюдь не азбучный - экономия денег на ремонте.Теперь, что будет, если этого НЕ делать.
В управляющей системе АКПП ("мозгах")есть некоторое кол-во клапанов, состоящих из пластмасски и пружинки, которые открываются от давления. При густом масле давление выше и пластмасску, если вы газанули с пробуксовкой, ломает. Следствие - пружинка с осколками пластика пролетает дальше и клинит шестерни. Поскольку приводная шестерня включения/выключения тоже из пластика - она ломается. Результат - коробка не переключает передачи либо выше 2, либо быстро перетыкается со 2 на 4. Если так поездить - засаживаются фрикционы и ремонт по полной программе.
Для тех, кто любит все делать сам - я бы вообще советовал перед зимой уменьшить рабочее давление на полоборота.
Via wiki & Internet