The hydraulic valve plate (Valve Body, valve body, valve block, "brains") is the "dispatcher" of the automatic transmission, the node automatic box, consisting of valves, sensors, accumulators and channels connecting them.
The hydroblock, like a board with transistors, converts electrical signals fromcomputer, distributes \ directs oil pressure from the pump to the desired clutch drum for gear shifting in automatic transmissionor blocking . 
We can say that the valve body plays the role- our footpressing the clutch pedal and
- our hand, shifting gearshift lever,
Moreover, he is also by such a lever
and also also brain (spinal) transmitting commands to the arms and legs.
The movements of the race car driver worked out to automatism, instantly and unmistakably shifting gears up or down - this is how the "brains" of the automatic transmission are programmed and according to the most efficient and economical scenario, switching is performed: squeezing the clutch of the working clutch pack - equalizing the speeds of the shafts - engaging the clutch of the next speed.
The whole technology of switching to another speed has been worked out by the designers so perfectly that the power gap in the most intelligent 6 ... 8-speed automatics during acceleration is less than 0.2 seconds. That is, almost infinitely.
The computer settings have been adjusted to save fuel and optimize acceleration so that the driver can squeeze the maximum out of the engine in the most loaded and aggressive modes. And the slightest sticking of clogged (or worn) valves first leads to jerks when switching, and later to clutch slippage in general.
 The hydraulic valve plate is called in professional slang - " Brain".
This is partly because it purely outwardly resembles the brain with its convolutions. Partly - because in the 20th century the valve body performed the function of the "brain" of the car, making decisions: when and which node should be included in the work. Indeed, the valve body was the true brain of the hydraulically controlled transmission, controlling the shifts with simple mechanical devices like Governors (compare: "tutor" - manager of the household). And that hydroblock hydraulic automatic transmissions The 1980s looked like the brains of lizards or fish. With the advent of electronics and solenoid valves, the real "brain" was not the valve body, but the ECU ( electronic control unit). And the hydroblock has become something like a "spinal cord". Together with the ECU - automatic transmission computer, the automatic transmission valve body is the real brain of the transmission. |
TCM, ECU, PCM and Valve Body - what's the difference?
The "brains" of an automatic transmission consist of two important nodes: Electronic transmission control unit ( ECU or TCM-eng.- transmission control module - left - yellow block) And Hydraulic valve plate (valve body, in the picture on the left - below is a gray valve plate). And between the valve plates - the most capricious part that needs to be replaced - the valve body gasket. The first (ECU) works electric shock and impulse-commands (like the cerebral cortex - through neurons) based on information from sensor sensors, and the second (Hydroplate) - works hydraulic oil- "supplies blood and produces hormone chemistry", controlling the entire body. Previously, the ECU was located under the hood or under the panel of the car. And since the beginning of the century, it has become customary to combine capricious electronics with a hydraulic plate inside the automatic transmission, where working temperature considered more stable. That is intellectual brain (ECU) automatic transmission connected to hydraulic brain (valve plate).This made it possible to simplify the design of the automatic transmission, but complicated the task for electronics manufacturers. But this is not the whole "brain" of the car. There is also the "brain" of the entire machine - the ECU (Engine Control Unit or Module). Some adventurous automakers have combined all the computers into one and called it the American Powertrain Control Module. This is the "brains" of the whole car. Rather, this is a combination of the "brain" (ECU), which controls the engine and the entire machine, and the "spinal cord" (TCM), which controls the automatic transmission. |
Typical malfunctions hydroblocks.
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Wiring fault Short circuit or broken wires. A favorite malfunction for craftsmen, which usually starts with valve body diagnostics. Easy to diagnose, easy to treatreplacement of wiring without expensive and time-consuming dismantling of the box. On the right - the most popular German machine wiring in repair . |
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Cleaning the valve body and solenoids very often solves switching problems. The hydromechanical valve plate is usually very mature and robust construction, which is designed to serve the entire life of the car. But it requires regular maintenance: changing the oil as soon as it gets dirty and maintaining a “normal” temperature fork (each box has its own “norm”) The main problem of hydroblocks is "old age" individual elements and dirt channels - "atherosclerosis": Valves, spools and plungers clogged with frictional dirt prevent the springs from returning the valve to its place or the solenoids from opening this valve, (cleaning solves these problems) The surfaces of channels, couplings, spools scratched by abrasive "garbage" wear and oil leakage through them (checked by Sonnaks equipment - No. 100301.) Worn consumables: Weakened springs returning the plunger to its place, crumbling paper gaskets or worn out metal gaskets, balls, filters clogged with dirt, hard rubber rings, etc. (replacing consumables solves most problems).
A home-made disposable pallet (usually a couple of pieces: on the right and on the left) is made of thick cardboard, bending an "accordion" out of it, into the furs of which the parts are folded in the order in which they stood in the hydroblock. |
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Faults solenoids - electrovalves . ( ). Checked with diagnostic equipment (resistance, operation, wear...). Washed, repaired with replacement of bushings or replaced completely.Solenoid malfunctions - more . |
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On the left is a table for checking the automatic transmission JF414 (Lada Granta), which helps to diagnose all the solenoids and the sensor through the chip. |
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Malfunction electrical boards, diagnostics is performed according to . Most electrical boards are successfully repaired by replacing burned-out elements. Most often, the sensors built into the board burn. See your page. |
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Malfunction (contamination or wear) of the elements of the hydraulic plates, aging of consumables - valve body or separator plate gaskets, rubber seals, metal elements, filters. The most common source of all problems caused by overheating and dirty oil, mainly due to worn clutches and adhesive layer, which friction linings glued to a steel base. Cleaning the hydroblock with complete disassembly this is the same routine operation for an automatic transmission master as cleaning a Kalashnikov assault rifle for a soldier after shooting. |
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Violation of tightness due to hardened rubber, due to which the oil does not get where it is needed, or vice versa - it gets where it is not needed. So the most popular consumables were "glasses" from the bestseller ZF6HP or "adapter" for the same machines, responsible for emergency oil leaks. Every year hydraulic plates become more reliable, all elements of the plate subject to wear are transferred to the solenoid design. On the page of each automatic transmission, the most likely reasons for which the valve body requires service are described. |
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For bulkheads, a home-made or special pallet (100301) is very helpful for sorting and storing valve body parts.
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Modern valve plates in 5 and 6-speed automatic transmissions that use linear solenoids operate in very different conditions: One of the problems is fever. Since 2003-2005, the operating temperature of the engine (and in the automatic transmission) has increased from 95°-100º to 20-30 degrees. Electronics age faster when operating at temperatures above 120ºС.
When the oil in the valve body does not move along the full section of the channel, but through a partially open valve, then at this moment in the narrowest place friction occurs increased wear surfaces: both the spool-plunger (left) and the valve body metal itself. The body of the plate is made of aluminum alloy, and this problem was solved by anodizing abraded aluminum surfaces.In the 2000s, a way was found: - to transfer this "bottleneck" from a massive plate - to a small solenoid. Now the solenoids have their own spool valve. And more expensive anodizing made it much easier to repair worn valves. It became easier to change the worn-out assembly (with the solenoid itself). |
 Fast acceleration are achieved due to the fact that all clutches (and especially the donut clutch) are switched from the "" torque converter (and clutches!). Now the switching takes place according to a complex kinematic scheme and is almost imperceptible, using clutches much more intensively.
Because of this, the oil heats up faster, and the clutches litter more. Oil pollution causes "atherosclerosis of the brain" - deposits of compressed friction dust mixed with metal chips from the wear of metal parts. This dirt is deposited in all quiet corners (plate valves, spools, solenoids) and makes it difficult for the valves to work, as well as wear out the friction surfaces and impair cooling. It is these fresh deposits that are washed out during the change, which, together with the exfoliated friction paper, clog the channels of such an "old and sick" plate. |
Hydroblock maintenance
The design of modern (6-speed) automatic transmissions began to be designed in such a way that the valve body is located not from below, where it is rather difficult to maintain, but from the side, and instructions for adding oil(for example -) as follows:
- At the first stage, when removing the side cover of the valve body (enough to change the solenoids) - it is required to add only 1.3 liters of oil. - With more complex repairs- removing and cleaning the valve body, you will need to add 3.9 liters of oil. And already at complex maintenance (when the "donut" is removed for repair - ) - 5.3 liters of oil.And only with the complete dismantling of the automatic transmission is full change oils.Thus, the intellectual leader of automatic transmission manufacturers, Aisin Co, constructively prepared services and owners for the fact that automatic transmission maintenance is divided into stages:
The first maintenance of the automatic transmission: cleaning and replacement of solenoids and repair with the removal of the side cover and cleaning of the valve body (without expensive dismantling and installation of the automatic transmission itself).
The next regulatory level: Removal and repair of the Torque Converter with the replacement of a worn clutch (or 2-3 clutches in some ZF -32 or).
And only after these routine worksoverhaul of the entire transmission with dismantling will be required.
What if you still ride with a "kicking" valve body?
Depending on the location of the failure, you have to pay differently.
On the Sonnaks diagram ( left) shows where problems occur in case oil leaks V different places hydraulic plates:
Some leaks lead to abnormal operation of switching 1-2, ... 3-4 speeds.
Others - to an inoperative blocking of the transformer with the ensuing problems of overheating and excessive fuel consumption,
Still others - to a general lack of pressure, which leads to the development of metal for axles and bushings. - Frequent problem for the legendary ZF boxes 6HP26.
The most popular place for repairs is a valve that includes a torque converter lock-up and a corresponding LockUp solenoid. It is here that the dirtiest and hottest oil passes until it is cleaned and cooled by passing through the sump, radiator and filter.
The longer the spools work with crumbs that have fallen on the sliding surfaces, the deeper scratches or abrasion of the valve body. When the body of the valve body is worn out over the allowable 30-50 microns, it is necessary to change the hydraulic plate itself.
Hydroblock repair.
Some valve body problems are solved by "remote repair" - read about your valve body on the corresponding page. Click on the orange part number to learn about this possibility.
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№1: Of the most popular, Mechatronic for - 26 - # 181740 . They order the so-called "Rebuild" - Restored Mechatronics. Restoration and sale of these not so difficult, but very capricious boards is made byZF. |
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No. 2. Often they order a new Electrical board for the Mercedes automatic - #194446.
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№3. Another frequently repaired valve body board is Dzhatkovskaya: - № 319446 , board elements burn out. Repair of the removed board is carried out according to fault codes and usually takes 2-3 days. Masters attribute this problem to voltage fluctuations, which usually occur when lighting up or when the battery terminals are removed on a running car.Prices can be found by clicking on the part number on an orange background. |
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Of the most popular replacement valve bodies - Control Plate / Valve Body /09G. №134740 . The problem is most often the abnormal operation of worn out solenoids. Previously, craftsmen habitually sentenced the valve body itself to be replaced, but now more and more often they simply replace a pair of faulty solenoids. (). In non-started cases, when the hydraulic plate itself has no leaks ( see test purge -) then replacing the solenoids helps extend the life of the box by several years. ( When working with clean oil). |
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Another popular replacement hydraulic plate is from Aisin's bestseller. There, too, recently, the craftsmen began to change the stove itself less often and more often order solenoids (a typical set of -3 pieces - 351428K) for replacement. In principle, it is very difficult to kill this plate. Quite technological cleaning of the plate itself. And a very difficult and unpredictable job of cleaning the solenoids. Therefore, both the Americans and the Taiwanese have produced exact copies of the original solenoids, which are currently being ordered instead of replacing the entire hydraulic plate. |
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In third place in terms of popularity of orders for the replacement of the valve body is the growing Hydroblock - No. 346740. And in this valve body, the same problems are repeated as in the 5-speed brother. The most replaceable solenoids that usually solve the beginning problems of the valve body are Large: 346421, 346422, and small gas turbine lock solenoid: 346425. But if the channels during purging give numerous leaks, then you have to change the entire valve body. automatic transmission. You can find out the price by clicking on the part number on an orange background. |
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The problems of both boards are associated with overheating and violation of the characteristics (temperature-resistance) of some elements of the board (sensors). Once installed, this Board may require a dealer registration.Repair and cleaning
Repair of modern hydroblocks begins with the collection of computer data - codes and most often consists in the bulkhead of the valve body.
Dismantling and assembly with cleaning and replacement of consumables - routine work, which is done every day in all automatic transmission services and which automatic transmission manufacturers recommend doing at the same time as repairing the torque converter and replacing the filter.
Without waiting for the clutches to wear down to the adhesive layer, in order to finally clog the plunger and abrade the plate channels to unacceptable backlash. It's like with brake pads- if you drive to the squeak "iron-on-iron", you will have to change everything.
Many people clean the valve body on their own, if you have patience, photos and collect the experience of online forums for repairing your transmission.
Restoration of hydroblocks is a work of a completely different level. Automatic transmission repair guru - the American company Sonnaks produces a lot of materials, instructions, tools and parts with the help of which specialists with golden hands and brains perform complex operations to restore the work of a worn hydraulic plate.
But this is such a difficult job with an unpredictable result that for most specialists it ends with replacing the valve body with a new one. And the replacement of "brains" is always expensive pleasure for those who are easy on them.
The easiest case of valve body repair is at an early stage of the disease. When it is enough to clean and rinse the valve body, replace its consumables and, if necessary, -.
No, an even easier case is when the wiring that powers the solenoids and sensors is faulty. This is generally done in a few minutes and is quite inexpensive.
This is partly true, but knowing design features Automatic transmission and the principle of its operation, you initially extend the life of your gearbox. In this article, we would like to tell you about the basic mechanisms and principles of operation of an automatic transmission..
Content:
What is an automatic transmission?
An automatic gearbox is an important structural element of a vehicle's transmission, which serves to change the torque, direction, and speed of the vehicle. and for long-term separation of the engine from the transmission. There are stepless (CVT), stepped (Hydraulic) and combined gearboxes (Robotic).
It's no secret that the transmission has a major impact on the dynamics of the car. Manufacturers are constantly testing and implementing Newest technologies into our cars. Nevertheless, most motorists prefer to operate cars with a manual transmission, as they believe that the latter brings much less headaches. This is partly true, but knowing the design features of the automatic transmission and the principle of its operation, you initially extend the life of your gearbox. In this article, we would like to tell you about the basic mechanisms and principles of operation of an automatic transmission.
What better manual transmission or automatic transmission
As a rule, our domestic car enthusiast treats automatic transmissions with certain prejudices. Apparently the reason for this is our chronic unwillingness to shift our problem onto someone else's shoulders and an attempt to eliminate it on our own. For example, the Americans, and it was they who invented the automatic transmission, do not suffer from this. In America, mechanical gearboxes are not very popular, and only 5% of American motorists out of a hundred use mechanics. The popularity of automatic transmission in Europe is growing from year to year at a tremendous pace. Of course, there are also fans of the machine gun among our compatriots, but not everyone succeeds in operating them correctly. According to auto mechanics, it was the untimely tech. maintenance and improper operation is often the root cause of all automatic transmission failures.
How does automatic transmission work?
In order to understand the principle of operation of an automatic transmission, we will conditionally divide it into three parts: hydraulic, electronic and mechanical. As you might guess mechanical part is directly responsible for gear shifting. Hydraulic transmits torque and creates an effect on the mechanical. Electronic is the brain that is responsible for switching modes (selector) and feedback with vehicle systems.
As you know, the heart of the car is the engine, in the case of the gearbox, this is just as appropriate. The transmission must convert the power and torque of the engine in such a way as to provide the necessary conditions for the movement of the vehicle. Most of this hard work is done by the torque converter (aka "donut") and planetary gears.
torque converter depending on the speed of the wheels and the load, it changes the torque automatically and performs clutch functions (as in a manual gearbox). In turn, it consists of a pair of bladed machines - a centripetal turbine and centrifugal pump, as well as between them is a guide vane-reactor.
The turbine and the pump are as close as possible, and their wheels are shaped to provide a continuous circle of circulation of working fluids. It is thanks to this that the torque converter has minimal dimensions and minimal energy losses during the flow of liquids from the pump to the turbine. The engine crankshaft is connected to the pump wheel, and the gearbox shaft is connected to the turbine. In view of this, the torque converter does not have a rigidconnections between the driven and leading elements, the flows of working fluids transfer energy from the engine to the transmission, which is thrown from the pump blades onto the turbine blades.
How automatic transmission works video:
Fluid coupling and torque converter
As a matter of fact, the fluid coupling works according to the same scheme, without transforming its value, it transmits torque. The reactor is introduced into the design of the torque converter in order to change the moment. In principle, this is the same wheel with blades, only it is rigidly planted on the body and does not rotate until a certain time. A reactor is located on the path along which oil returns from the turbine to the pump. The reactor blades have a special profile; the interblade channels gradually narrow. Due to this, the speed of the working fluids flowing through the channels of the guide apparatus gradually increases, and the liquid ejected in the direction of rotation of the pump wheel from the reactor drives and pushes it.
What is the automatic transmission made of?
1. torque converter- similar to a clutch in a mechanical box, but does not require direct control by the driver.
2. planetary gear- similar to a gear block in a mechanical box and changes the relative ratio in the machine when shifting gears.
3. Brake Band, Rear Clutch, Front Clutch- they are used for direct gear shifting.
4. Control device- this is a whole assembly consisting of a gear pump, a valve box and an oil sump. The valve plate (valve body) is a system of channels with valves (solenoids) and plungers that perform control and management functions; it also converts the engine load, the degree of pressing the accelerator and the speed of movement into hydraulic signals. On the basis of such signals, due to the sequential inclusion and exit from the operating state of the friction blocks, the gear ratios are automatically changed.
torque converter planetary gear
Differences in the device of automatic transmission of rear-wheel drive and front-wheel drive cars
There are also a few differences in device and layout. automatic transmissions rear wheel drive and front wheel drive vehicles. In front-wheel drive vehicles, the automatic transmission is more compact and has a compartment inside the case. main gear i.e. differential. Otherwise, the functions and principles of operation of all automatic transmissions are the same. To ensure movement and perform all functions, the automatic transmission is equipped with such components as: a torque converter, a command and control unit, a gearbox and a drive mode selection mechanism.
rear wheel drive car front wheel drive car
Has survived for over a century evolutionary development. In recent decades hydromechanical box gear that does not require the driver manual switching transmission stages, has become a very popular vehicle layout option and is increasingly being installed on vehicles various price segments.
Hydromechanical gearbox: principle of operation and device
The classic design of the car implies the presence of two mandatory blocks in it:
- gear box;
- clutch.
Such a description is suitable for a mechanical box familiar to motorists for many decades. But over time, as technology develops, other variations of the gearbox assembly began to appear, providing a person behind the wheel with greater comfort of movement.
The transmission is one of the basic components of a car. Thanks to it, transmission from the engine of the car to the wheels is ensured. In the automotive business for many years reigned supreme manual transmission, which provides for the blocks described above in its design. The driver had to perform three consecutive operations:
- disconnect the car engine from the transmission at the time of switching (depress the clutch);
- give a command to change the torque by moving the gearshift lever to the desired
- position;
- depress the clutch, returning the engine to the wheels.
But the situation has changed, engineers have created a checkpoint where there is no clutch pedal. The process of driving a car for a person in this case is greatly simplified: the ECU switches to desired gear myself. Management is made by brake and gas pedals.
Starting off, the driver depresses the brake, moves the selector to position D (Drive), releases the brake, and starts moving. The automatic transmission shifts to 1st gear, 2nd and further by itself, depending on the speed of the car, the position of the gas pedal, engine speed and other factors, the control of which is carried out by many sensors.
This process is ensured by the use of several technologies, among which the hydromechanical gearbox is the most famous, “run-in” in production and reliable. In it, the change of gears on the clutches is carried out by means of circulation under pressure gear oil by box.
A modern hydromechanical transmission is a complex device consisting of the following main components:
- ECU - the electronic "brain" of the box, and control mechanisms;
- oil pressure pump;
- springs and channels of the hydromechanical system;
- mechanical box.
The latter is not a typo, the automatic transmission is really based on “mechanics”, structurally supplemented with blocks automatic switching with a torque converter - hence the name of the unit. A typical hydromechanical gearbox in the context:
The history of the automatic box began in the first quarter of the 20th century: then concern Ford began to introduce the first samples of "hydromechanics" into their products. In the USSR, automatic transmission did not receive mass distribution among the end consumer, although, for example, at the end of the 50s, the LAZ plant, in cooperation with NAMI, developed and introduced a hydromechanical transmission into buses of the LAZ-695Zh series. Later, it was also used in the LiAZ-677 model, about 200 thousand buses were produced with automatic transmission.
Hydromechanics LAZ in the context:
In the modern automotive industry, “automatic” is very common, even in budget models of cars.
About torque converter
The heart of the type of box under consideration is a node called a torque converter. His device can be seen in the diagram:
IN general case device and principle of operation of hydro mechanical box gears created on the basis of the planetary system can be described as follows:
- the force is transmitted to the main, or sun, gear (central, number 6);
- auxiliary satellites (indicated by the number 3) freely rotate along the axis and
- constantly linked by teeth with the central one;
- a carrier (number 4) is mounted on these satellites, communicating with the shaft (number 5);
- auxiliary elements are also engaged with the ring gear, indicated in the figure by the number 2.
The carrier, when the ring gear is stationary, transmits force to the driven shaft, when it is disinhibited, then through the satellites the force goes to gear number 2. The shaft itself remains motionless. Direct switching takes place by means of belt mechanisms and friction clutch packages.
Pros and cons of fluid mechanics
Summarizing the above, we can conclude: hydromechanical automatic transmission- this is a unit consisting of a torque converter, a manual transmission module (in most cases planetary), equipped with a clutch package, a system hydraulic control and controlling electronic block.
Of the advantages of such a bundle:
- driver convenience: no need to change speeds manually;
- power transfer from engine is coming without "drawdowns" and jerks, which is especially important when starting off.
But there are also obvious disadvantages. One of them is a relatively small, compared with mechanics, efficiency, which is due to the presence of a torque converter.
Important: in the process of circulation of the working fluid, part of the efficiency is lost: according to research, the efficiency of a mechanical box is about 98%, the same indicator for an “automatic” is in the range of 86-90%.
In addition, there are other disadvantages:
- high complexity of the assembly, an abundance of components, as a result, relatively lower reliability (although hydromechanical gearboxes can, with proper care, “walk” for decades, which is successfully shown by Japanese, Korean and German cars);
- higher cost of the box, which makes the car equipped with it more expensive;
- fuel consumption in a car with such a box is slightly higher;
- low maintainability, in comparison with the "mechanics"; successful repair requires sophisticated equipment and specialized knowledge.
But the advantages of hydromechanical gear shifting still outweigh its disadvantages, especially for novice drivers who do not have sufficient experience. In addition, in the urban rhythm of traffic, with constant traffic jams, the hydromechanical automatic transmission saves both strength and nerves of the driver, who does not have to perform endless “clutch-gear” manipulations and move at 1st speed with the clutch half depressed.
The automatic transmission valve body or hydraulic valve plate is the gearbox control organ and the most complex mechanism in it, a bit reminiscent of the human brain with its convolutions. It is a metal plate with milled channels into which control valves, sets of sensors and solenoids responsible for the operation of the box are installed. The valve block controls the clutch and torque converter lock-up, taking over the role of the clutch pedal and shift lever.
According to a certain program located in the control unit, it switches, aligning the speed of rotation of the gears and including next gear. The automatic transmission takes much less time to perform these actions than a person. The computer builds the gearbox control in such a way as to adapt as much as possible to the nature of the car owner's driving and provide the necessary smoothness and fuel economy, while squeezing the required power out of the engine.
The valve body of modern automatic transmissions consists of the plate itself and the electronic control unit. The plate itself is the body and blood vessels of the automatic transmission, the control unit is the brain.
Depending on the manufacturer and automatic transmission model, valve bodies have a very different resource. It is not eternal and the part will break. Do-it-yourself repair is not possible. Repair of an automatic transmission valve body is not uncommon and it is well mastered by repair service specialists, it is much better to give your car away.
Typical malfunctions of the valve body on the example of different automatic transmissions
Automatic transmission 09G was developed Japanese concern Aisin. Volkswagen engineers took part in the development and adaptation, who in the Aisin team customized the 09G with their own hands to various engines. Automatic transmission 09G was installed on the Volkswagen Passat B5 and B6, Golf, Jetta, Tuareg, Audi A3 and other cars with engines up to 3.5 liters.
The box itself was not so reliable. On Volkswagen Passat B5, B6 and Taureg cars, this transmission often runs only 50,000-60,000 kilometers before the first serious breakdown. On the 09G automatic transmission, heat transfer is poor and the 09G valve body quickly fails due to overheating.
Owners of the Volkswagen Passat B5, B6 and Tuareg often violate the obvious rules of operation and overheat the automatic transmission, naively relying on the novelty of the car and German quality.
Because of this, the Passat B5, B6 and Tuareg may experience incorrect automatic transmission operation: shift delays, kicks and jerks. On some Passat B5, B6 and Tuareg cars, shifting can be accompanied by noticeable wheel slip even at a decent speed.
Slippage and emergency modes of automatic transmission on the Passat b6 and Tuareg can also be associated with incorrect operation of sensors and electrics. Often entire wiring harnesses fail in this transmission. At bad contact valve body with some automatic transmission sensors on the Passat B6 and Tuareg, a frightening behavior of the box can be observed, which, fortunately, does not require replacing the gearbox mechanisms.
In case of trouble with the Passat b6 and Tuareg box, you should start with an oil change, which you can do yourself. At the time of diagnostic procedures, when the first signs of a breakdown appear on the car, it is better not to drive, but immediately take it to the service. If there are no options and the car is needed for some time, then the transition to manual mode switching may be a temporary solution.
If instead of oil in the box there is black sludge that has not changed for 120,000 kilometers, the Passat and Tuareg boxes simply will not work normally. If the matter is not in the oil, then everything, of course, is sadder. If the oil has been changed recently, then it should not be changed. For Tuareg and Passat, this procedure is not cheap at all.
Prices for the repair of the Passat and Tuareg valve body start from 35,000-50,000 rubles. Replacing an old one with a new one will cost about twice as much. It is possible to determine the cause of the malfunction only in the service, complex diagnostics may be required, for example, at the stand Valve Body Hydro Test.
You can extend the life of the box on the Passat and Tuareg as follows:
- Monitor the condition of the oil and change it in a timely manner;
- Always ride only on a warm box;
- In traffic jams, switch to manual mode to second gear. That will save the box from endless gear changes and dangerous overheating.
BTR boxes
The Ssang Yong Aktion Sport was equipped with a 4BTR M74LE box, developed in 1988. The Ssang Yong Aktion Sport box is notorious for the fact that it can begin to show the first signs of wear and incorrect operation on a run of only 12,000-30,000 kilometers. Many Ssang Yong Aktion Sport owners are forced to undergo long diagnostics and frequent repairs from official dealers, which often take 1.5–4 months. Not the best gift for people buying new SsangYong Aktion Sport.
Sang Yong Action with box 4BTR M74LE
Aktion Sport has a very “fun” automatic transmission. Often neither official dealers, neither the most professional specialists can figure out the defect and the reason for the strange behavior of the box. The scourge of Aktion Sport is usually strange, but very noticeable vibrations that occur at any speed, and accidental operation of the automatic transmission emergency mode. Quantity possible troubles appearing in the Aktion box can be described for a long time. Here are a few examples of Aktion malfunctions: when worn, the torque converter gasket clogs the valve body with its remnants, old filters are equipped with bad magnets that simply do not catch metal dirt that clogs and breaks everything that is possible in the automatic transmission, when slipping, the box often switches to emergency mode due to for initially incorrect operation of the speed sensors. In general, Aktion with a gun is better not to take.
6T box family
A six-speed automatic transmission 6T- was installed on Chevrolet Cruze, Aveo and Epik cars. This gearbox is of a modular type and it is maximally unified with its entire family. Therefore, spare parts for the repair of the Chevrolet Cruze gearbox are always full. Typical problem valve body Chevrolet Cruze is a failure of the internal electronics due to obsolescence.
The entire solenoid block on the Chevrolet Cruze has to be changed, in order to soften the switching, it always works as a team, however, it serves a lot, and this gearbox design saves the torque converter for a long time. When bushings and rings are worn on a Chevrolet Cruze due to oil starvation these solenoids will wear out very quickly.
Worn or clogged valves lead to jolts when shifting gears, or even to the failure of the box to work with one or more of them.
At high temperatures operation of the Chevrolet Cruze gearbox and if the oil is old, the Hall sensors may not work correctly. Which leads to incorrect operation and shifting of 4-6 gears on a Chevrolet Cruze. This is usually indicated by the twitching of the Chevrolet Cruze while driving. Like all modern machines, The Chevrolet Cruze gearbox is very sensitive to overheating and running on dirty and old oil.
Four-speed automatic transmissions u241e from the manufacturer Toyota were installed on the most popular and reliable front and all-wheel drive models, such as Camry, Avensis, Celica, etc. The u241e gearbox is a very reliable transmission and it is still installed on cars.
Compared with younger brother u240, u241e it has been slightly strengthened for more powerful motors which made it even more reliable. Although the concept of "reliable" should be used for u241e only in the light of modern realities. In terms of the number of requests due to failure, this gearbox is only slightly inferior to the DP0 and ZF 5HP19. Although in defense of Toyota cars it is worth saying that cars with this gearbox go much more and break down rather because of the unwillingness to part with reliable car too much for a long time. Childhood illness u241e is poor wiring of contacts inside the valve body, due to which pressure jumps and packages burn. Fortunately, such a malfunction for the u241e is easily fixed without removing the box. Basically, trouble occurs on old Toyota Rav 4 equipped with u241e.
Toyota Rav 4 equipped with u241e
Unfortunately, with the introduction in early 2000 of worldwide controlled wear and tear in the production of cars and their parts, and laws that make the use of old cars unprofitable, the quality of cars and automatic transmissions has dropped terribly. Manufacturers simply stopped making their cars reliable.
Cars must now serve no more than three years and then the motorist must buy a new one (in a number of countries, for example, in Japan, this is prescribed at the legislative level). For the sake of comparison: automatic transmission 31TN, produced from 1981 to 2001 (part of the design has been preserved from its predecessor from 72–78) for american cars with multi-liter powerful engines, it still serves easily, it is easily repaired and 10–20 times cheaper than boxes on new cars with the first problems. The mileage of such boxes can exceed 1 million kilometers before the first overhaul. But unfortunately they don't do that anymore. Modern automatic transmissions require very careful handling and do not like violations of the operating instructions.
