New automatic transmissions (automatic gearboxes) will greatly facilitate driving, they themselves choose which gear should be engaged at one time or another, thereby allowing the engine to operate in acceptable modes, which, of course, avoids its breakdowns. However, when buying a car equipped with an automatic transmission, it is worth considering some features of such a transmission.
In the classic "machine" there is no clutch. It replaces special device- a torque converter, in which the rotation of the engine is transmitted to the gearbox shaft not by friction of the disks, but by means of a special transmission fluid. In fact, unlike the clutch, which can be engaged or disengaged, the torque converter is always "on", the car's smooth starting is achieved by a non-rigid connection between the engine and gearbox.
Unlike a manual transmission, the "automatic" has one interesting mode - P - parking mode. In this case, the car is in neutral, and the output shaft of the automatic transmission is blocked. This mode is similar to parking brake, however, for example, it is better not to use it on a slope - most likely, the shaft lock will simply fail under the weight of the car.
A car equipped with an automatic transmission cannot be started from a pusher. Therefore, car owners need to carefully monitor the condition of their " iron horse", or rather - behind the spark plugs, battery, electronics, etc.
There is one more feature in the operation of a car with automatic transmission - if the car is stuck, then pull it out by swinging, i.e. method of alternating inclusion of the first and reverse gear will not work.
The resource of an automatic transmission is somewhat less than that of a manual transmission and averages 300,000 km for middle-class cars, 150,000-200,000 km for small cars.
Fulfillment of all recommendations for operation and maintenance, movement in a quiet mode significantly increase the resource of the gearbox.
If there are noises, vibrations, hard shocks and delays in gear shifting in the transmission, please contact us! Timely handling will reduce repair costs.
Our center produces qualified repair, trained personnel on high-quality equipment.
Kickdown. Another one interesting feature automatic transmission, which ordinary "mechanics" does not have. The essence of this phenomenon is simple - when you sharply press the gas pedal, the car accelerates sharply. When driving, this is achieved by switching not to overdrive, but down! In this case, the engine speed increases sharply, and, as you know, by high revs the engine is more “accelerating”, which means it responds faster to pressing the gas pedal. Kickdown is useful when overtaking, when you need to accelerate the car sharply, however, and fuel consumption increases dramatically.
The automatic transmission may not have gears at all! Such a gearbox is called a variator, in it gear ratio does not have a fixed number of levels, the speed switches gradually. With constant acceleration of the car, the engine operates in a constant mode, which favorably affects its condition, and fuel consumption in this mode is minimal. The only minus of the variator is the unusual uniform rumble of acceleration, as, for example, in a trolleybus.
An automatic gearbox is undoubtedly a convenient thing, but do not forget that, like other components of a car, it requires a certain amount of attention. What does this mean?
And this means only one thing - it is necessary to periodically carry out special maintenance of the automatic transmission, which includes checking the oil level (once a year or every 15,000 km) and replacing it (every three years or every 45,000 km). As in any other business, there are nuances here. That is why it is better to entrust the replacement of oil in the transmission to specialists. But you can check its level yourself.
A few rules that allow you to increase the resource of automatic transmission:
- Starting off and changing the direction of movement to the opposite, you need to switch the selector lever with the brake pedal depressed and with the car completely braked.
- You should start moving only after a characteristic push, which indicates full inclusion transmission.
- When stopping at traffic lights, as well as short stops and stops in traffic jams, you do not need to set the selector lever to position N. And it is not recommended to do this on long descents. Violations this rule usually can lead to wrong work automatic transmission mechanism.
- If the car has stalled, then pressing the gas pedal is harmful both for the automatic transmission and for main gear. In such cases, you can try to downshift, work the brake pedal as a clutch, thereby ensuring that the wheels rotate slowly.
- Regularly check the oil level, as oil starvation is one of the main causes of automatic transmission failure.
The operation of the car leaves its mark on the resource of components and assemblies. The more intensively the vehicle is used, the more loads experiencing. Among the mechanisms, the power plant and gearbox experience large friction forces and temperature differences.
Work (ICE) is associated with temperatures generated during the combustion of vapors fuel mixture. During the working stroke, the pressure inside the cylinder reaches 10MPa and the temperature exceeds +2000°C. An automatic transmission (automatic transmission) is also subject to thermal stress. At the moment of gear shifting, the clutch surface temperature reaches +400°С. Full load, heats the hydraulic transformer up to +150° and above. Do not forget that the automatic transmission and the engine are operated at low temperatures, which also leaves a negative imprint.
To protect the machine and the power plant, excessive temperature fluctuations, increased friction, mechanical inclusions etc., the design provides for lubrication. Lubrication in automatic transmission and power unit is designed to protect mechanisms and minimize the negative impact of aggressive environments.
Over time, intense riding and hard use vehicle leads to the fact that the liquid is not able to cope with the task. The basic design characteristics of the oil are not enough to meet the needs of worn mechanisms.
In order to extend the life of installations and eliminate early failure, companies in the field automotive chemistry Resource additive was developed. The use of additives in the engine and automatic transmission improves the quality of the units and increases the operating time.
Description and purpose of additive Resource (DVS)
The Resource additive was created thanks to the use of new technologies, suitable for restoring the performance of the power plant without disassembly. The basis of the substances used are particles of metals with a soft structure, such as tin, silver, copper. Thanks to the formula, the Resource additive is able to restore the crystal lattice of surfaces damaged by friction.
- Functions Additive resource:
- Restoration of damaged surfaces of engine parts;
- Reduces carbonization of oil in the engine;
- Increases engine compression;
- Increases fuel efficiency of the engine;
- Reduces the noise of the engine;
- Reduces the amount of burning in the engine exhaust.
Principle of operation ICE additive resource, indications for use
The task of the additive resource is to restore the working capacity of mechanisms. The principle is based on the creation of a film of small particles that envelop the surfaces of parts and the walls of the units of the unit. Sealed gaps increase the efficiency of the power plant and give an increase in power. Metal impurities fill microscopic cracks, chips and shells, due to which a layer of alloys is formed.
The Resource additive helps convert thermal energy into mechanical energy. The process takes place without disturbing the heat transfer of the power plant, which has a positive effect on the unit.
- The vehicle has traveled 60,000 km. and more;
- Oil consumption is 150 grams per 1000 km. and more;
- Fuel consumption is higher than normal;
- The compression index in one or more cylinders is below normal;
- The operation of the power plant is accompanied increased noise and vibration.
If most of the symptoms described above are present, it is recommended to apply the additive Resource for recovery normal operation motor. The additive will be delivered with the help of oil to the desired areas, in which exposure to temperatures activates microscopic particles. The formed porous structure will create protective film and protect the mechanism.
Application Resource additive for internal combustion engines: features
One tube, 50 ml. it is recommended to dissolve in oil, the amount of which is 4-5 liters. This proportion has a positive effect on the characteristics of the oil and makes the protection process stronger. The use of two packages for the same amount of oil restores the elements of the cylinders and pistons. At a dosage of three bottles or more, it is recommended to fill the drug in portions, the mileage between applications is at least 50 km.
Additive dosage Resource for the engine:
- Start power unit, warm up to operating temperature after driving 10-20 km;
- Stop the engine;
- Intensively stir the contents of the vial by shaking;
- open oil filler neck engine;
- Pour the contents of the bottle into the neck;
- Start the power plant, let it run for 20 minutes at idle.
Important! Before using the additive, it is necessary to replace the old oil with a new one. When changing the oil, change the filter element. Following the recommendation will remove the impurities contained in the engine.
Performing actions in the manner prescribed by the manufacturer will lead to a result after the vehicle has traveled 2000 km.
Important! The additive is also used after the engine has been repaired. The main condition, holding full run-in unit before applying the mixture.
Factors influencing the effect of using additive resource:
- The state of the power plant;
- Quality and condition of engine parts and components;
- The quality of the oil used;
- The quality of the fuel used;
- Grease change frequency.
Description and purpose of additive Resource (automatic transmission)
Just like in engines internal combustion, The resource restores the performance of the box and extends the period of operation until the moment when interference with the product cannot be avoided.
- Additive functions Resource:
- Improved and balanced operation of automatic transmission;
- Extended automatic transmission mileage;
- Makes automatic transmission quieter;
- Restoration of damaged layers and parts of automatic transmission;
- Restoration of automatic transmission products made of rubber and plastic;
- Does inner space Automatic transmission cleaner;
- Elimination of places of lubricant leakage from automatic transmission;
- Makes the automatic transmission work smoother.
The period of application of the additive for automatic transmission is comparable to the change period, every 25,000 km.
Principle of operation Additive resource for automatic transmission: indications for use
Principle of operation The resource of the additive for automatic transmission is similar to the principle of operation of the additive in the engine. The additive contains a component, the basis of which is a powder of an alloy of copper, tin, silver. By creating a solid anti-corrosion layer at the point of contact, the additive evens out the defects. An automatic transmission additive designed to operate at temperatures lower than those experienced by the power plant.
- It is recommended to use the Resource additive for symptoms:
- Automatic transmission shifting is slower than it was before;
- Switching automatic transmission is accompanied by a knock and extraneous sounds;
- Transmission lubricant is subject to frequent overheating;
- Unit mileage, 60,000 km or more.
Application Resource additive for automatic transmission: features
Before using the additive, read the instructions for the automatic transmission, and the Resource. The dose to be strictly adhered to is one tube (50 ml) per four liters of gear lubricant.
Important! It is extremely important that the application of the additive occurs with mandatory replacement transmission fluid. The design of the automatic transmission is sensitive to the presence of foreign impurities in the oil formed by friction.
Sequence of actions when applying additive resource:
- Perform the procedure for draining the transmission fluid from the automatic transmission, according to the rules established for the transmission model;
- Shake the contents of the tube vigorously;
- Pour the suspension from the tube into a container with fresh gear lubricant;
- Stir the mixture thoroughly;
Important! Do not use additive Resource (automatic transmission) bypassing the mixing procedure with gear lubricant in a separate container.
- Pour the resulting mixture into the automatic transmission, based on the instructions for changing the oil for the box model;
- Start the power plant, let it run for 5 minutes, then transfer the gear selector to the modes possible for use, making a delay on each for at least one minute;
- Drive a car in a gentle mode for 20 km or more.
Compliance with the requirements of the additive manufacturer Resurs and the designers of the automatic transmission model will avoid unpleasant consequences with the operation of the box in the future.
Precautionary measures
By manipulating with power plant and automatic transmission, remember that the cost of mechanisms is high. In addition, constructively, each model is individual and requires a differentiated approach.
Compliance with the rules will extend the life of the engine and automatic transmission:
- Before performing work, read the instructions for the engine, automatic transmission, Resource additive;
- Work is recommended to be performed on mechanisms warmed up to operating temperature;
- When applying the Resource additive, change the oil to a new one, both in the internal combustion engine and in the automatic transmission;
- If you have any questions, please contact certified centers for advice;
- The effect of using the Resource additive is directly related to the quality of the oil used in the internal combustion engine and the transmission fluid in the automatic transmission;
- Buy mixtures that meet the requirements, beware of fakes;
- Before buying oils, liquids and additives, visit the official website of the manufacturer, get acquainted with the characteristics of the product, features;
- Request a product warranty from official representative, refusal to provide a guarantee raises suspicion about the origin of the product;
- Compare the packaging and product protection elements with the packaging on the official website;
- Check the date of manufacture of products and the expiration date, do not purchase expired goods;
- Ask for an instruction manual in your native language;
- Demand certificates of quality, compliance and other related papers, check for seals, watermarks, holograms.
Automatic transmission resource
"Burned Oil" Automatic transmission resource. - If the oil has a burnt smell - Oil and gearbox life - When is it worth changing the oil in an automatic transmission? - Is it possible to cure an automatic transmission by changing the oil? There is a common myth: "If the oil is burnt, it is better not to change it, otherwise the car will stop." Indeed, such a pattern can be traced. And there is an explanation for this: What happens inside the automatic transmission when the oil smells "burnt"? From a lack of oil pressure (and not from overheating), the friction clutches are not compressed strongly enough by the hydraulics with each other (or to the steel discs), they slip and start to heat up from this. More often than others, the "eaten" friction lining in the torque converter burns oil. This is the first stage of automaton disease. There are tables for which operating temperature oil traditional friction linings (paper) begin to char. And although at the very beginning of work, when the friction clutch touches the steel disk, the temperature on the surface can point increase above 300 degrees, but the oil quickly cools the surfaces and the average temperature of the friction clutch is kept in the range of 100-130 ° C - the operating temperature of the oil. It is as safe as lightly touching a hot iron with a wet finger. And just as a finger burn occurs when the iron is touched for a long time, so the charring of the friction paper begins with prolonged exposure to temperatures from 130 degrees - when the oil temperature reaches 150 °, the charring process of traditional friction linings occurs like an avalanche, since the charred cellulose stops absorbing oil and cooling surface oil is no longer happening. And the adhesive layer turns into a brittle resin and the pad no longer adheres to the metal of the disc. Pieces of the burnt lining peel off and fly away with the flow of oil into free swimming. The heating of the friction surfaces reaches the "flash point" of the oil, which leads to irreversible changes in the structure of the oil itself and a characteristic odor. But the smell and quality of the oil are not so critical for the operation of the automatic transmission. Worse - consequences: glue and particles friction lining the channels and plungers of the valve body are clogged like blood clots, which leads to a lack of oil in the packages and at the shaft axes, in the nodes of the planets and beyond - no longer sliding, but rubbing parts of the pump, bushings, etc. are worn out. The very charring of the clutches leads to the same effect as a burned-out clutch manifests itself on the "mechanics" - the car seems to pull, but with an increase in engine speed, the speed of the car does not increase. Subtly at first, then more and more. (see "List typical faults Automatic transmission") Steel discs with such overheating get iridescent "tint stains." And they also need to be replaced. and the smartest part of the automatic transmission is the "brains" (valve body). Paper dust from the friction discs turns the oil into a thick abrasive pulp with small and large particles of the "sandblast" type. Like sandblasting, this hot stream under high pump pressure grinds out all the bottlenecks of the aluminum valve body, thinning the walls in places where the valves-regulators open and close the channels. Numerous fountains of leaks form. (left, click-enlarge) Mechanical "stroke". The valve body after this practically cannot be restored and must be replaced. Horror? But this is not the worst thing for our machine.The lack of oil pressure is primarily felt in the central part of the box - near the axle. insufficient oil centrifugal force curls up to the edges. And with a general lack of pressure, dry bushings near the axle, bearings wear out, the axles themselves wear out, the torque converter hub burns, the bearing parts of the drums, covers, planetary gear sets with the sun gear, accelerated wear almost all nodes of the "iron". Here it is: horror-horror. But "iron" is the main resource of the box. The "old age" of the box is measured precisely by the general wear of the rubbing surfaces of the above "iron" parts. A transmission resource can be considered such a state of all the main (expensive) components of the box, when the cost of replacing or restoring worn-out parts (usually a pump, valve body, planetary gear sets, shafts and drums, a cover ...) is comparable to replacing the box with a high-quality second-hand box and after such an overhaul, the transmission will last at least a couple more years. That is, if several important nodes, and the rest are on the way, then usually the masters recommend changing the box. And this end is approaching very quickly if you operate the automatic transmission with burnt oil or insufficient oil pressure. Like a year in three during the hostilities. Or pension 10 years earlier when working in an underground mine.
Will it help if you replace the burnt oil with a new one? Even the most expensive? Burnt oil is no longer a liquid, but a thick suspension of frictional dust and oil breakdown products. It is thanks to this thick friction suspension that the remnants of bald clutches somehow cling to each other and pull the car. They cry from burns and terrible pain, but they pull. 1. As soon as you make their work easier by replacing the thick slurry with clean fluid oil, so they (frictions) in exhaustion will stop clinging to steel discs and begin to slip, deciding that their well-deserved rest has come. 2. In addition, new liquid oil escapes more easily through the cracks of worn bushings and oak rubber pistons, which before that somehow still held the pressure of the old thick slurry. And last but not least: 3. liquid oil their detergent properties peels off the remaining "half-dead" friction linings (see here), which still somehow held onto the friction clutches, washes away dirt that has not yet caked from numerous quiet corners (radiator or heat exchanger) and drives all this suspension into the channels of the valve body and tightly clogs the solenoids and plunger . All in all, simple replacement burnt oil does not solve the problem, and can only exacerbate. In such cases, immediate hospitalization and repair is indicated. Minimum - removal and inspection of the pallet with magnets. At an early stage of the "disease", diagnostics may require: changing consumables and friction clutches, if the process has not gone too far. As a maximum - an autopsy will show. A sad master will leave the operating room and, sparing your feelings, will sadly read you a list of "dead" or "dying" organs that need to be removed and transplanted. Or vice versa - he will say that one Direct package burned out, and everything else is in good condition. There is always a chance for a healthy life after a major overhaul. The only questions are: "how long did you delay the repair" and "who will repair" And what will happen if you do not change the burnt oil and still ride? A normal person always has hope for a miracle: "What if it goes away by itself?" Or "We will solve the problem when the box rises!" It would be inhumane to take away a person's hope for self-healing. Does a cold go away on its own? Therefore, read above about "automatic transmission ending resource" and search in Yandex: "contract automatic transmission". The later you start treating the problem of burnt oil, the higher the likelihood of falling in love with your box to death
How often should you change the oil in an automatic transmission? Each transmission has its own manufacturer's oil change recommendation, but last years boxes have become much more complicated and these recommendations should not be trusted unconditionally. The fact is that synthetic oils, called "non-replaceable", really do not change their composition with time and temperature, unlike semi-synthetics and mineral oils 20th century. But still, there is nowhere to escape from the suspension that appears in the oil from wearing out friction clutches. The clutches of the box itself can last a lifetime and have a sufficient resource even after 300 tkm, but only if they have always worked with sufficient oil pressure. The most important friction clutch, on which the period of the first overhaul depends, is usually the friction clutch of the torque converter. And with the introduction of the controlled slipping mode of the GDT clutch, its life can quickly come to an end if the driver often forces the automatic transmission computer to turn on this mode with the gas pedal. Therefore, as soon as the entire working layer of this clutch is eaten up, in addition to the dust from the clutch, the adhesive composition also gets into the oil. All of these components can be so small and dissolved in the oil that they are not retained by the filter. And when their number reaches a critical concentration, then the accelerated aging of the nodes begins, as described above. So the oil should be changed not according to some standards, but based on its degree of contamination. Moreover, the older the clutches, the more often you should check and change ATF oil.
What if the oil already has a burnt smell? In a mild case (this is like going to a doctor at an early stage of the disease), you will have to change all the clutches of a burned-out clutch pack, repair the torque converter (donut), buy a repair kit for gaskets and seals and clean everything that is being cleaned, including the radiator. Well, if the master has tricky devices to really clean the radiator from the inside and out. But sometimes it makes more sense to replace the heat exchanger or radiator or install an additional one. In a neglected case, the box is so worn out that only someone who is used to dragging his dog (or cat) to droppers to the very end, regardless of spending and the result, will undertake to repair it. But most throw away such a box and look for a replacement BU. In the middle, there are options when the "weak points" of the box are on (see the corresponding page of the automatic transmission). Weak spots automatic transmission is still good. This means that, for example, by replacing burnt oil (with consumables) and drum F in the ZF 5HP18 (the craftsmen will evaluate the pump as undamaged), you can be almost sure that the rest of the iron will pass for several more years without the risk of getting another overhaul. Contract BU-machines are considered quite big risk. Of course, if there is not a single automatic transmission repair service within 500 km in the district, then the automatic transmission control unit is the only way out. In general, if you missed the replacement period and the oil has become dark dirty and has a burning smell, go for diagnostics and repairs as soon as possible in order to save the life of your box. Or take apart the box yourself. Most 4 mortars are easily repaired in the garage with patience, Yandex, a camera, skillful hands and a real "male spirit". There are a couple more alternative options. For example - to buy a lottery ticket along with a used box and then quickly sell a car to a naive compatriot, trying to hide remorse behind an honest look. By the way - in the film Brother-2, most likely, just such a case was described, when a car with a problematic automatic transmission was sold cheaply.
Automatic transmission is a much more popular type of transmission today for a number of reasons. First of all, given type The gearbox greatly simplifies the process of driving a car, driving becomes more comfortable and safer, since the driver is not distracted by gear changes, errors are eliminated when choosing a gear, etc.
At the same time, it is also well known that automatic transmission is a complex and “capricious” unit compared to mechanical box manual transmission. Naturally, the more complex the device, the greater the likelihood of serious damage.
However, in practice it often happens that reliable mechanics one driver fails earlier than the automatic transmission of another. In this article, we will talk about what resource the automatic transmission has, as well as what factors and features directly affect the life of the automatic transmission.
So, today there are several types of automatic transmissions: a classic hydromechanical automatic transmission, a variator or a robot. Although robotic transmissions have recently supplanted the usual automatic transmissions, it is the automatic transmission that remains the most common option.
We go further. Given that there are several types of automatic transmissions, it would be a mistake to assume that all automatic transmissions are unreliable. The fact is that, for example, a robot box is fundamentally different from a CVT or automatic transmission, CVT cannot be compared with DSG, etc.
In other words, the resource of one type of automaton can be very different from another. Suffice it to recall the old 4-speed automatic transmissions with a torque converter, some of which are considered to be the most reliable automatic transmissions in history.
These checkpoints could easily pass 500 thousand km. and more without any repair. If we talk about cheap single-disk robots of the AMT type, problems with the transmission and its elements on a new car may already arise by 40-50 thousand km.
- Robot box. Today, this type of automatic transmission is actively used by many automakers, while in budget segment manual transmission with one clutch (single-disk robot) actively took root.
Simply put, this conventional mechanics, however, clutch operation, gear selection and shifting is carried out automatically using servo mechanisms. The gearbox itself is reliable, however, problems often arise with the indicated servos (actuators) and the clutch.
The clutch often fails by 50-80 thousand km. mileage, actuators are also often non-repairable, that is, they need to be changed entirely. Given the high cost of servos and a small resource, it turns out unreliable and not at all budgetary. In other words, such a robot has the lowest resource among all automata.
Another type of manual transmission is the preselective two-clutch gearboxes, well known to ordinary motorists for Volkswagen Group and DSG gearbox. Such boxes are more reliable than single-disk robots, however, problems with them also arise, on average, by 100-150 thousand km. run. Clutch discs wear out, actuators fail.
To extend the life of a box of this type, you need to remember about updates software, undergo diagnostics, the box needs to be constantly “trained”, adapted, etc. at the slightest deviations and malfunctions.
If we are talking about a new car that falls under a guarantee, then up to 100 thousand you don’t have to worry too much about the resource robotic automatic transmission, however, further problems with the robot can cause a significant blow to the owner's pocket.
- CVT variator. This transmission is often installed on machines of medium and high class, How on passenger cars as well as crossovers. The advantage of the variator is the stepless change in torque, due to which it is achieved high level comfort and smooth running.
At the same time, the resource and reliability of the variator directly depends on the driving style and quality of service. First of all, the variator is sensitive to the quality and level of oil in the box, is not designed for high torque, and is afraid of sharply changing loads. On a car with such a box, it is undesirable to actively start from a standstill, skid, use the car for off-road driving, towing a trailer or other vehicles.
Also, during operation, the variator belt must be changed every 100 thousand km, since its rupture can cause a complete failure of the gearbox. It should also be noted low maintainability and high cost quality repair variator, the need to change frequently oil filter and oil (it is advisable to replace every 30-40 thousand km.).
At the same time, strict observance of all prescriptions and recommendations regarding the maintenance and operation of the variator allows you to increase the resource up to 200 thousand kilometers (taking into account regular replacement oil and variator belt). Otherwise, the variator may require repair by 120-150 thousand km.
- Hydromechanical machine. If we talk about the resource, this type of checkpoint when proper maintenance And competent operation different enough long term services.
Compared to analogues, a simple automatic transmission in this regard definitely wins, and by a wide margin. The design is time-tested, the gearbox withstands high torque, there are no servos and a fast-wearing clutch.
In practice, there are far from isolated cases when a torque converter machine nursed 200-250 thousand km. even without changing the oil and automatic transmission filter. The only thing is that this statement is true to a greater extent for simple and reliable boxes that were produced back in the 90s.
Summing up
As you can see, in terms of reliability, a conventional automatic machine with a torque converter has the largest resource, followed by CVT variator, followed by a preselective robot (for example, DSG) with two clutches and complete the list robotic boxes type AMT with one clutch disc.
At the same time, it is important to understand that the so-called maintenance-free automatic machines and gearboxes, in which oil is filled for the entire service life, are more marketing than real proof of the ultra-reliability of modern technologies.
The manufacturer knows that the oil in the automatic transmission is aging and needs to be changed. However, the calculation is simple and clear, the driver operates the car for warranty period without servicing the box. Then the "outdated" model after 3 years is changed to new car or the owner begins to spend money on expensive repairs or complete replacement worn out units.
Finally, we note that today you can find such versions of gearboxes in which it is simply impossible to change the ATF oil and the oil filter without removing and disassembling the unit. The fact is that these automatic transmissions do not have a traditional box pallet.
If the resource automatic transmission is a decisive factor when choosing, then it is better to refuse to buy a car with this type of “maintenance-free” automatic transmission or immediately prepare for certain difficulties and additional costs.
Automatic transmission resource
There is a common myth: "If the oil is burnt, it is better not to change it, otherwise the car will stop."
Indeed, such a pattern can be traced. And there is an explanation for this:
What happens inside an automatic transmission when the oil smells "burnt"?
From a lack of oil pressure (and not from overheating), the friction clutches are not compressed strongly enough by the hydraulics with each other (or to the steel discs), they slip and start to heat up from this.
More often than others, the "eaten" friction lining in the torque converter burns oil. ( on right)
This is the first stage of automaton disease.
There are tables at which operating oil temperature traditional friction linings (paper) begin to char. And although at the very beginning of work, when the friction clutch touches the steel disk, the temperature on the surface can increase pointwise over 300 degrees, but the oil cools the surfaces quickly enough and the average friction clutch temperature is kept at about 100-130 degrees - oil temperature. It is as safe as lightly touching a hot iron with a wet finger.
And just as a finger burn occurs when the iron is touched for a long time, so the charring of the clutch paper begins with prolonged exposure to temperatures above 130 degrees,
When the oil temperature reaches 150 degrees, the process of charring of traditional friction linings occurs like an avalanche, since charred paper does not hold oil and the surface is no longer cooled by oil - the adhesive layer turns into a brittle resin, crumbles into pieces and the lining falls off the metal.
And the pieces of the lining peel off and fly away with the flow of oil into free swimming. The heating of the friction surfaces reaches the "flash point" of the oil, which leads to irreversible changes in the structure of the oil itself and a characteristic odor.
But the smell and quality of the oil are not so critical for the operation of the automatic transmission. Worse - the consequences: particles of the friction lining clog the channels and plungers of the valve body, which leads to a lack of oil in the packages and at the shaft axes, in the nodes of the planets and beyond - no longer sliding, but rubbing parts of the pump, bushings, etc. are worn out.
The very charring of the clutches leads to the same effect as a burned-out clutch manifests itself on the "mechanics" - the car seems to pull, but with an increase in engine speed, the speed of the car does not increase. Subtly at first, then more and more. ( see "List of typical automatic transmission faults") Steel discs with such overheating get iridescent "tint stains". And they need to be replaced too.
At the second stage of raping the automatic transmission, the thrust disks and rubberized pistons overheat. Then - the clutch drum itself and neighboring nodes burn.
But what is even more unpleasant - the smartest part of the automatic transmission - the "brains" (valve body) is also wearing out intensively. Paper dust from the friction discs turns the oil into a thick abrasive pulp with small and large "sandblast" type particles.
Like sandblasting, this hot stream under high pump pressure grinds out all the bottlenecks of the aluminum valve body, thinning the walls in places where the valve-regulators open and close the channels. Numerous fountains of leaks are formed. ( left, click to enlarge) Mechanical "stroke". The valve body after this is practically not restored and must be replaced. Horror?
But this is not the worst thing for our machine. The lack of oil pressure is primarily felt in the central part of the box - near the axle. The remaining insufficient oil is driven to the edges by centrifugal force. And with a general lack of pressure, dry bushings near the axle, bearings wear out, the axles themselves wear out, the torque converter hub, the bearing parts of the drums, covers, planetary gear sets with the sun gear burn, and there is accelerated wear of almost all hardware components.
In short: horror, horror.
But this is - box main resource. The "old age" of the box is measured precisely by the general wear of the rubbing surfaces of the above "iron" parts.
resource transmission can be considered such a state of all the main (expensive) components of the box, when the cost of replacing or restoring worn-out parts (usually a pump, valve body, planetary gear sets, shafts and drums, a torque converter, a cover ...) is cheaper or comparable to replacing a box with a high-quality BU box and after such an overhaul, the transmission will last at least a couple more years.
That is, if several important nodes in the box are critically worn out at once, and the rest are on the way, then usually the masters recommend changing the box.
And this end is approaching very quickly if you operate the automatic transmission with burnt oil or insufficient oil pressure. Like a year in three during the hostilities. Or a pension 10 years earlier when working in a tunnel face.
Will it help if you replace the burnt oil with a new one? Even the most expensive?
Burnt oil is no longer a liquid, but a thick suspension of frictional dust and oil breakdown products. It is thanks to this thick friction suspension that the remnants of bald clutches somehow cling to each other and pull the car. They cry from burns and terrible pain, but they pull.
1. Once you make their job easier by replacing thick slurry with clean fluid oil, so they (frictions) in exhaustion will stop clinging to steel disks and will begin to slip, deciding that their well-deserved rest has come.
2. In addition - new liquid oil easier to go through cracks worn bushings and worn pistons, which until then somehow still held the pressure of the old thick slurry.
And finally the main thing:
3. Liquid oil with its cleaning properties peels off the remaining "semi-dead" friction linings(see here), which still somehow kept on friction clutches, washes out not yet caked dirt from numerous quiet corners (radiator or heat exchanger) and drives all this suspension into the channels of the valve body and clogs tightly solenoids and plungers.
In general, a simple replacement of burnt oil does not solve the problem, but can only aggravate. In such cases, immediate hospitalization and repair is indicated. Minimum - removal and inspection of the pallet with magnets.
At an early stage of the "disease", diagnostics may require: changing consumables and friction clutches, if the process has not gone too far. As a maximum - autopsy will show. A sad master will leave the operating room and, sparing your feelings, will sadly read you a list of "dead" or "dying" organs that need to be removed and transplanted.
Or vice versa - he will say that one Direct package burned out, and everything else is in good condition.
There is always a chance for a healthy life after a major overhaul. The only questions are: "how long did you delay the repair" and "who will repair"
And if you do not change the burnt oil and still ride?
A normal person always has hope for a miracle: "What if it goes away by itself?" Or "We will solve the problem when the box rises!"
It would be inhumane to take away a person's hope for self-healing. Does a cold go away on its own?
Therefore, read above about "automatic transmission ending resource" and search in Yandex: "contract automatic transmission". The later you start treating the problem of burnt oil, the higher the likelihood of falling in love with your box to death.
How often should you change the oil in an automatic transmission?
The fact is that synthetic oils, called "non-replaceable", do not really change their composition with time and temperature, unlike semi-synthetics and mineral oils of the 20th century. But still, there is nowhere to escape from the suspension that appears in the oil from wearing out friction clutches. The clutches of the box itself can last a lifetime and have a sufficient resource even after 300 tkm, but only if they have always worked with sufficient oil pressure.
The most important friction clutch, on which the period of the first overhaul depends, is usually the friction clutch of the torque converter. And with the introduction of the controlled slipping mode of the GDT clutch, its life can quickly come to an end if the driver often forces the automatic transmission computer to turn on this mode with the gas pedal.
Therefore, as soon as the entire working layer of this clutch is eaten up, in addition to the dust from the clutch, the adhesive composition also gets into the oil. All of these components can be so small and dissolved in the oil that they are not retained by the filter. And when their number reaches a critical concentration, then the accelerated aging of the nodes begins, as described above.
So the oil should be changed not according to some standards, but based on its degree of contamination. Moreover, the older the clutches, the more often you should check and change the ATF oil. Read more - read here: ALL ABOUT AUTOMATIC GEAR OIL.
What if the oil already has a burnt smell?
In a mild case (this is like going to a doctor at an early stage of the disease), you will have to change all the clutches of a burned-out clutch pack, repair the torque converter (donut), buy a repair kit for gaskets and seals and clean everything that is being cleaned, including the radiator. Well, if the master has tricky devices to really clean the radiator from the inside and out. But sometimes it makes more sense to replace the heat exchanger or radiator or install an additional one.
In a neglected case, the box is so worn out that only someone who is used to dragging his dog (or cat) to droppers to the very end, regardless of spending and the result, will undertake to repair it. But most throw away such a box and look for a replacement BU.
In the middle, there are options when the "weak points" of the box are on (see the corresponding page of the automatic transmission). Weaknesses in the automatic transmission are still not bad. This means that, for example, by replacing ZF 5HP18 burnt oil (with consumables) and Drum F (the craftsmen will evaluate the pump as undamaged) you can be almost sure that the rest of the iron will pass for a few more years without the risk of getting another overhaul.
Contract BU-machines are considered quite a big risk. Of course, if there is not a single automatic transmission repair service within 500 km in the district, then the automatic transmission control unit is the only way out.
In general, if you missed the replacement period and the oil has become dark dirty and has a burning smell, go for diagnostics and repairs as soon as possible in order to save the life of your box.
Or take apart the box yourself. Most 4-mortars are easily repaired in the garage with the help of patience, Yandex, a camera, skillful hands and a real "male spirit".
There are a couple of other alternatives as well. For example - to buy a lottery ticket along with a used box and then quickly sell a car to a naive compatriot, trying to hide remorse behind an honest look.
By the way - in the film Brother-2, most likely, just such a case was described, when a car with a problematic automatic transmission was sold cheaply.
