Der Fox 30.11.2010 - 20:13

Today winter suddenly came, and even with a storm, the snow was terrible... as always, the city was “ready”... well, there was a sapper shovel... I spent half an hour digging out a puzoter at work, where the snow was already up to the hood, and it looked like in a station wagon... it seemed like I was in no hurry to get home... and at home I sat down a little...
I didn’t turn the speed... I tried to swing it a little bit by moving D-R... a little bit at a time, like it rolled out a snowball... I got out. Out of curiosity, I decided to look on the Internet... I read a bunch of senior students that “fse is an arctic fox”... you can’t slip on an automatic transmission, the gearbox is cranky, etc., etc....
I didn’t find anything smart... so is it correct to slip on an automatic transmission and what should not be done? that instead of D it is better to use 1 or L, I already understood 😀

gnom 01.12.2010 - 06:54

Slipping in itself cannot harm the machine in any way. The machine itself works on one continuous slip. It can be bad if unexpectedly the wheel grips the road well and confidently, and then the impact really doesn’t feel good.
And yes, you can slip in 1st gear so that the gearbox doesn’t switch.

crack 01.12.2010 - 07:30

you have to start with a snowflake. in this case, the automatic transmission immediately switches on the second or even the third and the fluid coupling cannot produce enough force to turn the wheels.

mnkuzn 01.12.2010 - 07:36

It all depends on WHAT EXACTLY you did, HOW you did it... Slipping in itself is just zilch. It is harmful to move the selector to a position that does not correspond to the direction of movement of the car.

How we swing on the “handle”:
1. We stick in the first one (well, or the back one, depending on where it’s easier to go at first).
2. We drive forward as much as possible.
3. Approximately at the extreme point we stick the back one - still IN MOTION.
4. When the car starts to roll backwards, we accelerate and drive back as far as we can.
5. Again, at the extreme rear point, we change the gear to first. Also on the move.
6. We repeat until we go in the direction we need.

And with an automatic transmission, we do the same actions, only points 3 and 5 are not done in motion, but we stop the car at the top of the trajectory with the brakes. In the stopping position, engage the opposite gear and repeat the swing. The main thing is not to change gears while driving. Well, instead of D, we turn on the first one (if there is such an opportunity) or drive in winter mode.

But... Everyone says: you can’t move, it’s harmful to the machine... Well, let them say. And it's really harmful. BUT!!! It’s up to you to decide whether to do it or not, but a couple of times I automatically drove out of a snowdrift into the swing without stopping. Those. I'm in APPROXIMATELY top point put it in the opposite gear, but did not stop completely (of course, when turning on R, I had to press the brake, but not for the purpose of stopping, but for the purpose of simply sticking this R). In short, as they say, “once, not...” (although this is debatable and I do not agree (please put this on the record), but that’s what they say 😀)...

The simple fact is that by sticking gears not when stopping, but while moving, we use the inertia of a moving car to a greater extent, thereby increasing the amplitude of the car's swaying - and constantly increasing the amplitude is the essence of swaying. If this is done regularly, I think it will harm the box. If a couple of times a season, I think it’s not a problem.

So I try to do it at a complete stop. But if THAT doesn’t work out, then I can do it manually.

Postoronnim V 01.12.2010 - 08:55

crack
you have to start with a snowflake. in this case, the automatic transmission immediately switches on the second or even the third and the fluid coupling cannot produce enough force to turn the wheels.

And before, yes, I pressed “manu”, the knob to two and it was clearly easier to get out of the snowdrift (or sand).

dikiy 01.12.2010 - 09:12

mnkuzn
And with an automatic transmission, we do the same actions, only points 3 and 5 are not done in motion, but we stop the car at the top of the trajectory with the brakes. In the stopping position, engage the opposite gear and repeat the swing. The main thing is not to change gears while driving.

That's what I do. And for more than one winter. And I’ll climb out of the snowdrifts.
The main thing is that you can “swing” at least a little

sergo_k 01.12.2010 - 09:38

Der Fox
So what is the correct way to slip on an automatic transmission and what not to do?

It depends on the car... On the Santa Fe you need to increase the gas for the viscous coupling to work...

crack 01.12.2010 - 09:41

only this is no longer swinging, but riding in the “groove”

mnkuzn 01.12.2010 - 10:32

Postoronnim V
Somehow these “snowflakes” are not visible now. And there is nothing good in this, IMHO.

Hello Andrei. We haven't talked to you for a long time. Why do you think that there is nothing good in the absence of winter mode? I drove in winter mode for some time until I got tired of the crazy fuel consumption. I stopped using it, the consumption immediately returned to normal (well, if this standard can be determined at all when driving in winter in city traffic jams), and in terms of starting from the first, and even uphill, I never had any problems - you just press on the gas smoothly, and the machine will do the rest itself. I didn’t see any advantages when starting from the second one.

Postoronnim V 01.12.2010 - 10:52

2 mnkuzn: Glad to welcome you, Mikhail! To be honest, I didn’t notice any crazy consumption in winter mode. He might have been bigger, but not by much. I drove in this mode in icy conditions, in snow and on sandy forest roads. To remove excess playfulness in the car. Maybe, of course, this was a feature of a particular machine, but it skidded in this mode less often, and when it got stuck, it went to R and 2 with manu better than to R and L without manu. Then there were (and still are) two cars with adaptive automatic transmissions - IMHO, for slightly extreme people road conditions worse.

mnkuzn 01.12.2010 - 11:18

To be honest, I didn’t notice any crazy consumption in winter mode.

I had an Impreza - clean a budget option: 1,5, front-wheel drive. In winter it was stored in 15 liters - taking into account warming up, traffic jams, etc.

In the first winter after purchasing this car, I initially drove in winter mode, and the box, as far as I remember, was like this: P-R-N-D-3-2 (in mode 3-2 it did not switch higher), the power button (switched up to more high speed), without manual mode. So the consumption when driving with the winter mode always on was about 18-20. I was just going nuts. It felt like gasoline was just leaking out... I went to the dealer and checked it at the stand. No violations were found, the master only advised not to press this button. Simply, he says, take off more smoothly, so it won’t slip into the axle box in first gear. I listened, and the consumption immediately returned to normal. But this did not affect the convenience and safety of driving...

And if I had to drive through snow or mud (this does not last long), then I simply set the winter mode and 2. The car started from second, but did not shift higher than second. Well, “in the build-up” I went to R and 2 with winter mode.

In short, I didn’t like the winter mode on THAT car due to the lack of advantages in control, but when increased consumption. And now there is not even such a button - neither winter nor power. But there is the possibility of manual switching - it’s very good on descents.

Postoronnim V 01.12.2010 - 11:40

2 mnkuzn: I had a RAV4-1, a permanent P.P. as a second machine and for the forest. In normal winter mode in the city I consumed 14-15 liters, in winter mode 15-16. Despite the fact that standing in traffic jams was approximately 3/4 of the total trip time. And the selector there 1-2-D-N and vice versa switched without stopping just with a push of the palm. Well, manu and power modes. At the same time I used another RAV4-2, constant P.P. The box is adaptive, there is no manual control of modes. The selector switches by pushing forward only. It is clear that to protect against fools - so that they don’t turn it on at two or below at 100 km. And everything seems to work well, but I still felt more confident on the first one. At least getting to the dacha on the second one in winter is a noticeably big problem.

Voices 01.12.2010 - 12:55

I wonder if Americans know that axle boxes are bad for gearboxes? They even have automatic transmissions on military trucks, but it’s hard to imagine what they’re doing with automatic transmissions.

crack 01.12.2010 - 13:48

why imagine? In America there is no snow and dirt - there is sand and stones.

dikiy 01.12.2010 - 13:55

crack
in America there is no snow and dirt - there is sand and stones

Yah?
Have you ever been to Alaska? Or in Canada? Or at least on the Lakes in winter?

dikiy 01.12.2010 - 13:58

What the hell is winter mode?
My old lady has an automatic transmission. So the modes are P-R-N-D-2-1. Plus Manu, PWR (I don’t use them). And also CDifLock Auto. I use them often. Both in winter and on mud.

mnkuzn 01.12.2010 - 14:17

What the hell is winter mode?

A button with a picture of a snowflake and the inscription Hold or Winter... When pressed, the car always starts in second gear. And the first one turns on when the speed decreases, as usual.

Postoronnim V 01.12.2010 - 14:20

2 dikiy: “Manu” is the same thing as “winter” mode. It’s just that on some machines that have the possibility of some additional. For manual control of automatic transmission modes, this button is indicated by a snowflake, but on others it is written “manu”. The bottom line is that gear shifting occurs at lower speeds, and if the selector is on two and “manu” is pressed, the box is forced into second gear. And on this second machine begins to move under tension.

Micro 01.12.2010 - 20:28

On old car That’s exactly what I did, went into a swing, changed gears at the highest points of the amplitude.
Now the gearbox is isitronic, you can safely start moving without fear of ruining something.

Der Fox 01.12.2010 - 21:42

I have it on the machine.. L-2-D-N-R-P... “snowflakes” I didn’t see anything there...
but don’t give a damn... at -23 it won’t start 😀 ...tomorrow I’ll remove the battery... strange... the voltage on the voltmeter seems to show 12 V, but it doesn’t really turn... as if mineral water is -40.. .although 5w-40 is synthetic...
Stsuk in general... but my ex “Zaparozhets” would have rattled off the first time..
p.s. damn I forgot to set up autorun yesterday... (...crying smiley...)

and what do you want from a battery with a capacity of 45A... even if it’s VOSH...

gnom 01.12.2010 - 22:20

I started it up at night at -27 on mineral water without any problems. Only interesting behavior. At first it immediately seizes, goes crazy and stalls, the second time everything is ok. And this has happened 5 times already. The truth is that it takes 15 minutes to warm up to working time.

Postoronnim V 01.12.2010 - 22:25

2 Micro: So the isitronic seems to be not an automatic transmission, but a robot.

2 Der Fox: That’s what I was talking about above. that nowadays snowflakes or “manu” are no longer visible for a long time. I don't have them on my last two machines either.
L-2-D-N-R-P... From manual control - only overdrive can be turned off and that's it. Adaptive automatic transmission, which kind of knows what it needs to do. And in practice, everything usually seems to be fine... And the car drinks a little less gasoline with it... But how does it know that sometimes it needs to start from second gear?
And older automatic transmissions had the ability to additionally control gears and their shift timing.

Der Fox 01.12.2010 - 22:27

Let's go... tomorrow I'll take a picture and measure the density... we're on the 2nd day of wild oak... at night it was -25... they promise until 30... for December 1st in the Volga region this is nonsense...

gnom 01.12.2010 - 22:31

Nevermind, you can’t tow a machine gun... that’s an ambush...

Slowly in neutral you can. The main thing is that there is something to grab onto 😀

Voices 01.12.2010 - 22:43

Der Fox
Nevermind, you can’t tow a machine gun... that’s an ambush...

why would this happen all of a sudden?

Postoronnim V 01.12.2010 - 22:50

Yeah. A common horror story. Which is not true
It is written in the manuals that a car with an automatic transmission can be towed. Well, maybe the formulas differ: 50x50 or 40x60... - these are little things.
By the way, about the build-up on an automatic transmission - the same thing. I often hear an argument against automatic transmission, and yet in the manual rocking is mentioned among the acceptable techniques.

crack 02.12.2010 - 01:33

what kind of swing is this if in a hole of one and a half wheels you need to switch from first to rear in a second, which is impossible with an automatic transmission.
but to tow it.... Fic knows what position the clutches and brakes are in when there is no oil pressure, and even the oil is frozen. rear-wheel drive cars with a manual transmission must also be towed with caution, periodically pressing the clutch and engaging the gear, because the gearbox is not properly lubricated if the input and intermediate shafts do not rotate

gnom 02.12.2010 - 05:46

Fic knows what position the clutches and brakes are in when there is no oil pressure, and the oil is frozen.

So P is neutral when all clutches are open. Put N and make sure the car rolls...

crack 02.12.2010 - 06:41

You might think that it won't roll to D if the engine is stopped.

gnom 02.12.2010 - 06:57

When the pump is not working, the car is turned off, the selector is in P, then the car is in neutral and in order to engage any gear, oil pressure is required, i.e. either start the engine or carry it in position D on a cord. By the way, the car also drags around quite well on D, and is not much heavier, but of course you shouldn’t do this...

Voices 02.12.2010 - 07:32

All automatic transmissions are different, of course, but on Lexus and Volvo there is a special little trick hidden, which you press when the engine is off and calmly move the selector to position N and slowly ride it on your tie.

in general, every car has a book that contains towing instructions, read it and you will be happy 😀

crack 02.12.2010 - 07:38

the point is that while there is no oil pressure, the selector can only pull out and push the parking clutch between the output shaft of the box and its body, and all other gears are actually equivalent and correspond to N

Postoronnim V 02.12.2010 - 08:05

Voices
All automatic transmissions are different, of course, but on Lexus and Volvo there is a special little trick hidden, which you press when the engine is off and calmly move the selector to position N and slowly ride it on your tie.

There is a service button for forced shifting of the selector on all automatic transmissions (at least that I have seen). On some it is disguised and to get there you need to pull out the plug (those who read the manuals know where and how to pull it out), and on some old Japanese ones the button is visible, and it’s red with a hieroglyph. When an inexperienced passenger sits down and asks “what is this button?”, the driver casually replies “yes... so..., a catapult for the passenger” 😊

Voices 02.12.2010 - 08:16

Postoronnim V

There is a service button for forced shifting of the selector on all automatic transmissions (at least that I have seen)

ugh, I just didn't pay attention to others. I just like our people (and not only ours, everyone is like that), religion doesn’t allow me to open the instruction manual. But what Uncle Vasya said from the fifth entrance, which the automatic transmission saw only in the picture, is perceived as the ultimate truth about the fact that you can’t tow / pull / drag trailers with an automatic transmission.

Der Fox 02.12.2010 - 09:36

Postoronnim V
the button is visible, and even red with a hieroglyph

this is exactly what it looks like... but I don’t think it will come to towing...

What kind of winter is this... I also can’t charge the battery... because... the locks open and close with the alarm without any problems, but if you remove it, then there is no way, because the larvae are frozen .. the defroster does not help...
By the way: there is a normal VAZ battery for 60A. Is it possible to connect it to my 45A circuit through crocodile clips for starting in severe frosts? Will there be any overloads there?

Novice car enthusiasts ask experts “whether it’s possible to skid with an automatic transmission.” Even before the machine gun came into life modern car owners There has been a lot of debate on this topic. Some experts were even inclined to believe that with two radiators on frame SUV, you can overcome mud and swamps.

But, after several dozen experiments, experienced car owners can accurately answer that skidding or a sharp start can only be done by mechanics. The automatic is designed for city roads and does not tolerate swamps.

Operating principle of the machine

The operating principle of the automatic transmission is:

1. The pump wheel in the torque converter builds up pressure and moves lubricating fluid to the turbine.
2. The donut transmits torque to the planetary gear when the drive clutch from the drive shaft is engaged.
3. And the valve body sets the algorithm for oil circulation and gear movement in the planetary gear by shifting gears.

Due to the fact that automatic transmission is independent system, almost independent of a person, it is prohibited to skid on an automatic vehicle.

Attention! Cannot be withdrawn vehicle out of a snowdrift by rocking back and forth, as manual drivers do. Constantly switching the selector lever will not only damage the switch itself, but will also harm the automatic transmission.

What happens to an automatic transmission when it slips?

The consequences of machine slipping are fraught major repairs Automatic transmission. As the temperature inside the machine rises, the friction force of the metal parts against each other increases.

The box must cool down in case of long-term slipping.

The torque converter and friction discs are heat sources in the automatic transmission. If the loads are huge, then more heat is generated. The operating temperature can not only be similar to the engine temperature, 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, most rarely, installed separately, and in this case cooling occurs with the help of air.

An unnecessary result may appear in the event of prolonged slipping; in the automatic transmission, the temperature of the lubricating water (ATF) increases. This liquid may boil if heated. In this situation, this fluid stops lubricating the automatic transmission parts. 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 breakage of the box.

There is no need for long slipping; the box needs some time to rest. It is not recommended to turn off the engine when slipping.

If the car is not warmed up, it is better not to skid.

Similar consequences await you in this situation. The ATF fluid has not yet been heated to the required temperature and, accordingly, has not received the appropriate viscosity. Automatic transmission parts that are subject to movement without lubrication will wear out sharply.

Before you start driving your Automatic transmission out of a snowdrift, first switch to R mode with the brake pedal pressed. Stay in this position for a few minutes. Start moving in this case, when the torque converter itself fills with the required amount of lubricant and goes into working condition.

Delay transmission.

Let's take a closer look at the buildup. During slipping, a large load is placed on the torque converter, which can lead to its failure. If the temperature rises, the oil loses its characteristics, the pressure decreases - this will lead to the torque converter being cut off or the clutches to burn out.

During long slipping, you need to delay the transmission. The most important thing is to switch from R to D mode with a fixed gear; this can be done through the brake pedal. It is not recommended to immediately press the accelerator and brake pedals.

Try to avoid getting sudden traction after slipping.

Slipping, towing or long driving at high speed - all this shortens the life of the clutches.

Inside the differential gearbox, located in automatic transmissions, there are heavy gears, and an axle passes through the entire gearbox housing. If the wheel hits a hard surface while slipping, the impact can lead to the axle breaking. The part pierces the body of the automatic transmission at high speed.

So, try to avoid sudden traction after slipping.

What cars are not recommended to slip on?

The enormous 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 80-90s

You can find a box with an air cooling system in old Japanese and European cars. Vanes on the torque converter housing provide air flow to dissipate heat. It is impossible to slip on such automatic transmissions, because... Cooling occurs only while driving. Today's “Europeans” and “residents of the land of the rising sun”, who have such automatic transmissions, are in no way among those “not leaving the snowdrift”.

Tips for owners of cars with both automatic transmission and manual transmissions(everyone will find something useful for themselves when slipping).

• When 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 there is a small opportunity for acceleration, you can continue your journey.

• Try to drive slightly in the opposite direction when there is a danger of slipping. 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 traction while driving, it is recommended to place corrugated floor mats from the interior under the front wheels.

• In order to ensure that the next time you move from a stop without hindrance, it is not recommended to brake sharply, since the tires will create a smooth surface underneath. Under the influence of rest, the car's wheels will not stop in uncompacted snow.

• A car with an automatic transmission does not need to skid in place for a long time. Try to leave “swinging”. Do not forget about the position of the selector R and D in order to switch between modes in a short time. If there are fixed stages “1,2,3”, swing in mode R and 2. Do not forget that it is often not recommended to accelerate in the snow. Under no circumstances should you step on the gas suddenly.

• Janitor's shovel winter time more productive, unlike sapper or other shovels.

• If you cannot get out of a 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 forward and backward, using 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, this directly concerns the car that will free your car. Before securing the cable, first check that the eye is securely fastened. Then engage first gear. When the cable starts to tighten, you can start driving out. In this situation, be careful and vigilant.

On the drive wheels, and automatically selects the desired stage.

Also, during operation, the owner may encounter that the automatic transmission is slipping, gears are not engaged in a timely manner, jerks, bumps, shocks of the automatic transmission, etc. occur when switching. Next, we will talk about why the automatic transmission slips, as well as how to fix this problem.

Let's start with the fact that the automatic transmission consists of three main parts, each of which performs certain functions.

• . The torque generated by the engine is increased by the 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 blocking 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 a planetary gearbox.

Normally, an automatic transmission ensures ease of driving a car with automatic transmission and maximum comfort. However, during operation, an automatic transmission, like any other vehicle mechanism, can fail.

As mentioned above, transmission breakdowns often manifest themselves as noticeable jolts when changing gears. And also slippage may occur automatic transmission gears at different stages. At the same time, the difficulty of diagnosing an automatic transmission malfunction often lies in the necessary complete dismantling of the entire unit.

Signs of automatic transmission slipping

Slipping of the automatic transmission is manifested by slight slipping when the accelerator pedal is sharply pressed or when shifting to a higher gear. With such slippage, traction is lost and the car engine begins to idle.

If you continue to operate the automatic transmission without paying attention to this malfunction, then in the future the slipping will increase significantly, the box will begin to slip even when starting from a standstill, as well as when the automatic transmission is switched to both a lower and higher gear.

Why the automatic transmission slips: reasons

Slipping when shifting gears of an automatic transmission to a higher gear often indicates the use of poor quality or one that has lost its properties. transmission oil. Also in this case, it is recommended to check the oil level. The oil should not be below or above the required level.

In this case, the problem is solved by replacing the transmission oil and air filter Automatic transmission. It should be remembered that replacement can only help with slight slipping when changing automatic transmission gears.

• If slipping occurs only when the automatic transmission is switched “to cold,” then it is necessary to check the clutches (friction discs). Friction discs are installed on the 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 the planetary gearbox (sun gears in a certain order) to be rotated. At the same time, clutches are short-lived and wear out over time (with a vehicle mileage of 200-250 thousand kilometers).

The problem of clutch malfunction is solved by replacing them. The work of replacing friction rings is quite labor-intensive and complex, as it requires dismantling, full analysis transmission, after which the condition of all moving elements inside the automatic transmission is assessed.

• Hydroblock. Clogged valve body channels do not allow for a high-quality supply of ATF to the moving elements. The hydraulic unit channels are cleaned using cleaning chemicals under the influence of ultrasound.

This work is carried out only on the removed valve body and is very labor-intensive. Also, after repairing the valve body, it is recommended to replace all filters of the car and, accordingly, the transmission oil in the automatic transmission.

• If the oil change is completed, but slipping occurs when the automatic transmission is switched “to hot,” this means that the solenoid block and/or 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 a low level, then the problem lies in the solenoids or in the pump.

It is solved by replacing all failed elements, and for more correct operation of the automatic gearbox, it is recommended to change the solenoids in “packages”. This will ensure their proper operation and reduce the risk of recurrence of this breakdown.

• Another one of possible reasons If the automatic transmission slips, there may be a malfunction 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 at each specific moment in time about the state of the controlled area during the operation of the automatic transmission itself, actuators, etc.

To accurately check the automatic transmission ECU and determine the problem, you must contact service center for high-quality and accurate diagnostics. If a defect is detected, the problem is often solved only by complete replacement. electronic unit automatic transmission control, since the device is often irreparable.

Let's sum it up

If slipping, jolting or jerking in the automatic transmission begins to appear when the car is moving, you need to contact a service station for high-quality and accurate diagnostics.

In the first case, the nature of the breakdown is determined based on the readings of diagnostic instruments; it is often possible to normalize the operation of the box using a trivial procedure.

In the second case, in order to determine the degree of complexity of the breakdown, the automatic transmission is dismantled and completely disassembled. The specified actions are carried out if the cause of box slipping may be a malfunction of the valve body or a malfunction of the automatic transmission friction rings.

Accordingly, the cost of the repairs performed will depend on the specific breakdown of the automatic transmission and the total scope of work. It is important to remember that even a simple oil change and oil filter in the machine is a rather labor-intensive and costly procedure. For this reason, you need to clarify in advance how much it costs to change the oil in an automatic transmission.

Checking the oil level in an automatic transmission: how to check the ATF level. What else to pay attention to: color, smell, ATP contamination, etc.

Automatic transmission solenoid: design of solenoids, operating principle. Frequent malfunctions and breakdowns of solenoid valves, diagnostics, repair and replacement.

1. Let the box cool down in case of prolonged slipping

The main sources of heat generation in an automatic transmission are the torque converter and friction discs. Moreover, under heavy loads the heat generation is quite large. The operating temperature of the transmission is comparable to the engine temperature, and may even exceed it. Therefore, cars with automatic transmission have a special cooling system, the radiator of which is either built into the radiator of the engine cooling system, or - much less often! - installed separately and cooled by air flow.

Most often, adverse consequences arise for the very reason that during prolonged slipping in an automatic transmission, the temperature of the automatic transmission lubricant, called ATF (Automatic Transmission Fluid), increases. When heated, this liquid has poor viscosity and sometimes boils. As a result, it ceases to perform its function and no longer lubricates the automatic transmission parts. As a result, the friction discs are destroyed.

We should not forget that when friction clutches rub, the temperature in them also rises sharply - up to 200-250 C. This thermal shock reduces their service life, and in some cases (if you do not stop slipping) leads to instant transmission breakdown.

So, in principle, you can skid, but not for long, periodically giving the box a rest. However, the engine should not be turned off.

2. Do not skid when the car is not warmed up

Similar consequences await you if you start slipping in a cold car. Only in this case, the ATF fluid, on the contrary, has not yet warmed up to the required level and has not acquired the required viscosity. If you act hastily, automatic transmission parts that move with virtually no lubrication will wear out intensively.

Therefore, before trying to drive an automatic transmission out of a snowdrift, turn on R mode with the brake pedal depressed and wait for about a minute. The torque converter itself will pump in the required amount of lubricant, bringing it into working condition - after which you can start rocking the car, trying to pull it out of the snowdrift.

3. Lock the gear (on tiptronics or in mode L1, L2)

Now about the buildup itself. At the moment when the car slips, a huge load is created on the torque converter (sometimes even a shock), which can instantly disable it. As the temperature rises, the oil loses its properties (after all, performance depends on the pressure created in the box by the oil), the pressure drops, and either the torque converter (aka the donut) cuts off, or the clutches burn out - this depends on the situation.

Therefore, when slipping for a long time, you need to fix the gear and not jump from one to another. And most importantly - switching from R mode ( reverse) in D (or L1,L2) with a fixed gear can only be done through the brake pedal. You cannot press the gas and brake at the same time!

4. Avoid the possibility of sudden traction after slipping

Any increased load reduces the service life of the clutches. This applies to slipping, towing, and long-term driving at top speed.

There is such a part in an automatic transmission - a differential gearbox. inside there are small but heavy gears, an axle passes right through the entire gearbox housing... If a slipping wheel hits a hard surface, the impact on the axle can be so strong that the axle is torn out, the parts fly apart at the speed of a bullet and pierce the automatic transmission housing in several places at once...

Therefore, it is impossible to allow sudden traction with the road to occur after slipping.

What cars are not allowed to slip?

Increased heat generation in the torque converter can be critical if the cooling system has low efficiency (the automatic transmission cooling radiator is clogged with wear products). As a rule, this occurs in cars with high mileage - old American monsters built in the 80-90s. It’s high time for them to change the gearbox, or even better, scrap them themselves.

In addition, on old European and Japanese cars you can find boxes with air system cooling. There are additional external blades on the torque converter housing, with the help of which they organize air flow to remove heat. Such automatic transmissions are cooled while driving, which means it is not recommended to slip on them. However, the above applies only to ancient small cars that are rare among us. They are not intended for use in harsh conditions. Modern “Europeans” and “Japanese” equipped with automatic transmissions are not among those “not allowed to leave the snowdrift”.