The simplest way to check the variator yourself

A CVT is similar to an automatic transmission in that you do not have to constantly control the gear shift using a lever, as with a manual transmission. But in principle there are fundamental differences. The automatic transmission includes fixed gears, often from four to nine, and the variator (CVT) does not have fixed gears.

The CVT has only one gear without steps. Photo: avto-dny.ru

What causes a variator to break down?

The main cause of known malfunctions of CVTs is violation of basic operating rules:

• the oil or filter element was not replaced on time;
• use of low-quality oil;
• aggressive driving style;
• prolonged driving at maximum speed;
• sudden braking.

Additional causes of malfunctions can be various defects in structural components (defects, ill-conceived design, poor-quality connection), as well as natural physical wear and tear of the constituent elements, which manifests itself after 150,000 - 200,000 km.

CVT malfunctions can occur both in its electronic control module and in mechanical components.

Electronics defects

In the first case, detection of a specific breakdown is carried out using computer diagnostics. A diagnostic code is assigned to each defect. Thus it is easy to determine:

• problems with the electronic control module board;
• defects in the speed sensors of both pulleys, operating oil temperature, pressure in the main line or pulleys;
• malfunctions of the stepper motor, defects in the blocking valves of the hydraulic transformer and control of the operation of the planetary gearbox, solenoid valves for pressure in the main line and the driven pulley.

The probable cause of a defect in the electronics may also be a violation of the integrity of the electrical wiring or unreliable contact in the connector.

Mechanical problems

Computer diagnostic tools are not the only tools used to detect mechanical problems. In this case, it is necessary to approach the problem in a comprehensive manner and monitor the parameters of the working fluid, conduct road tests, read the diagnostic code, and clarify signs of malfunctions.

avtoexperts.ru

Despite the fact that the first production cars equipped with CVTs appeared back in 1958, this type of automatic transmission became especially widespread in the late 80s, and was mainly used by Japanese automakers.

More and more automakers are choosing CVT or CVT (Continuously Variable Transmission) as automatic transmissions for their vehicles. The leaders in the production of CVTs in the world are several companies: Aisin and JATCO, both Japanese companies, the first belongs to Toyota Motor Corporation, the second Nissan Motor Co., Ltd. But you shouldn’t think that only the Japanese know a lot about CVTs. CVTs are also produced by Audi, Mercedes-Benz, Ford...

Read about the variator device here

As with any other gearbox, the principle of a variator is to change the gear ratio of torque from the engine and redirect it to the wheels, but structurally it is a completely different unit. The CVT transmission does not have a specific number of gears, and for this reason it is often called a “continuously variable” automatic transmission.

Despite a number of advantages of the CVT, the owners of the first production cars equipped with such gearboxes were dissatisfied. In addition to some mechanical problems, they also encountered a number of operational limitations, such as the inability to tow a trailer for a long time, CVTs do not like fast acceleration and long slips, and cars with this type of transmission are very limited in raising engine power. All this can cause premature problems with the unit.

Now let's take a closer look at what the owner of a car with a CVT may encounter.

1. The first thing that owners of used Nissans and Subaru began to complain about was the wear of the cone shaft bearings. All this is accompanied by a hum, and can occur both at 50,000 km and at 100,000 km. Although the unit is repairable, it is better to rely on the factory warranty, since replacing all four bearings will be very expensive.

Shafts with bearings and belt

It is better not to delay the repair, since if the bearing is destroyed, the tapered shaft itself will also be destroyed. Also, when play forms on the shaft, the metal plates of the belt also suffer. This problem can be prevented by changing the CVT oil once every 50,000 km. The cost of changing the oil is also not cheap, and the transmission fluid itself is more expensive than ATF for a classic automatic transmission.

2. When changing the oil in the variator, you should strictly adhere to the manufacturer’s instructions and do not skimp on the original oil. Since the CVT is a complex mechanism, it is very demanding in terms of compliance with tolerances and standards. Otherwise, saving a couple thousand rubles can accelerate wear and tear and entail even more waste.

3. Since any transmission does not like high temperatures, heat exchangers are often installed on CVTs.

variator heat exchanger. Photo — drive2.ru Svyazist91

This device is a radiator, which includes transmission oil from the CVT, and through another channel, antifreeze from the internal combustion engine cooling system enters the heat exchanger. The first reason that the oil in your variator has risen above normal is most likely a clogged heat exchanger. It should be washed every two to three years. Overheating can also be caused by the fact that the transmission fluid has accumulated a lot of sludge and deposits and requires replacement. Overheating the oil in the box to a critical temperature will cause the variator to go into emergency mode and everything will return to normal only after the unit has cooled down.

Mitsubishi Outlander CVT overheating signal

4. Like a classic automatic transmission, a variator can “kick” as it is called. The reason very often lies in the oil pump pressure reducing valve. Due to its unstable operation or non-function, the oil pressure may constantly “jump” or not rise at all.

Oil pump

This problem can only be solved by replacing the valve, or the entire pump. In addition, the shafts may need to be ground, and the belt will most likely require replacement. The sooner you contact a specialist for repairs, the cheaper this repair will cost you, since operating a car with a faulty variator will simply aggravate the situation.

Like any complex mechanism, there are a number of conditions in the operation of a variator that must be met for its trouble-free operation. Very often, breakdowns are associated with improper operation or untimely maintenance, but nevertheless problems exist, and manufacturers try to fix them from year to year. Something is working out, something is not yet happening, but the trend of changing classic automatic transmissions to CVT has been visible for a long time, and I think that in the foreseeable future, more and more cars will be equipped with a CVT.

Author - Andrey Chervyakov

Detection of defects by external manifestations

Many variator malfunctions can be identified by characteristic external manifestations, but such “diagnosis” has one significant drawback - the manifestation of different defects may be the same. This is reflected in the table below.

The most serious and materially costly defect of the above is the defect of the variator transmission. It occurs when the belt slips between the pulley cones with the simultaneous formation of scoring at the ends of the belt segments and the working surfaces of the cones. This problem can only be eliminated by complete replacement.

How to check the variator

Let's consider the main ways to check the variator:

• checking the car while driving;
• hearing test;
• checking the condition of the oil.

Most motorists consider the “automatic” to be a more successful option for the gearbox, but the CVT is considered more modern. Of course, CVT has its disadvantages and advantages.

Let's take a closer look at each method of checking a variator, which will help determine its condition and protect you from buying a faulty car.

Everything that is currently known about the UAZ 3170 crossover is in our material.

You can find out how to select and install an electronic tachometer here.

Bearing wear

This is the most common defect in CVT cones. It manifests itself with a characteristic hum after a run of at least 50,000 km.

The belt is assembled from numerous plates interconnected by steel constrictions. With its side surfaces, with subtle oblique notches applied to improve adhesion, it comes into contact with the pulley cones. During operation, the notches wear out, which can ultimately lead to serious damage. Therefore, even the elimination of humming bearings should be accompanied by a preventive replacement of the belt, which guarantees the preservation of serviceable pulleys.

Bearing noise can also occur for several other reasons:

1. Poorly manufactured bearings.
2. Insufficient dynamic load capacity, as well as a low degree of bearing accuracy, lead to their overload and destruction.
3. Penetration of wear products (small powder-forming particles) onto working surfaces, leading to destruction of the latter. This may be due to a large amount of metal powder clogging oil filters and weakening the field of the magnet installed to collect it. In some cases, this problem can be solved by changing the oil more frequently (approximately every 30,000 - 50,000 km).

There is no consensus among manufacturers on this issue. For example, Mitsubishi strongly recommends changing the oil every 75,000 km, while Renault-Nissan only allows monitoring its level and condition during the warranty period (100,000 km).

CVT oil is marked with the abbreviation CVT. Every car manufacturer has such oil. The original composition from Nissan is produced under the symbol NS-2. Mitsubishi is promoting the DiaQueen CVT-J1. The analogue from Renault is known as ELFMATIC CVT. Honda produces HMMF and CVT-F, VAG produces ATF CVT. All these fluids are recommended specifically for CVTs. It is absolutely unacceptable to use oils intended for hydromechanical automatic transmissions.

The amount of oil required for filling is determined by the type of drive and power unit. For example, for a front-wheel drive Qashqai with a 2-liter engine not equipped with an oil cooler, approximately 4.2 liters are required. A couple of liters will “get stuck” between the transformer elements and the hydraulic system components, since it is impossible to pump out these “drops” using the standard draining procedure. To completely renew the filling, they use the replacement method, using an appropriate installation and three times the volume of working fluid.

Is the CVT as scary as it is made out to be?

Some car components are famous for their practicality and durability. But heroes always have an antagonist. In the car, this unenviable role went to CVTs. There are legends about their unreliability and irreparability. Are they true?

"Tragic" but popular

Some potential buyers believe so strongly in the depravity of the CVT that they refuse to purchase the car they like. What if it breaks? So what, throw out tens of thousands on repairs? And many official dealers do not repair CVTs, but simply replace them. And this, of course, is a completely different amount if the unit is not under warranty.

But if the “officials” show conservatism regarding the CVT, then many workshops have mastered the repair of this “miracle beast” - and clearly did not lose money. Moreover, this is typical not only for capitals, but also for more or less large cities throughout Russia.

One way or another, concerns from year to year are expanding the list of cars they produce that have CVTs installed. This forces some to fussily look for a suitable option without the “striped devil”, while others look at the recent “enemy” with less apprehension.

The Japanese Jatco continuously variable transmission has gained particular popularity among automakers. CVTs from this company are installed on French Renault, Peugeot, Citroen, Japanese Suzuki, Mitsubishi, Nissan, and even on American Jeep and Dodge. And the most common CVT model is JF011E. It is she who switches gears on most cars of the listed brands. The company is not weak: X-trail and Qashqai, Latitude and Megane, Lancer and Outlander, Citroen C-Crosser and Peugeot 4008, Dodge Caliber and Jeep Compass - and so on. There is no point in listing everything; the picture is already clear.

If CVTs were really as bad as people think and say about them, it is unlikely that so many brands would have been “deceived by the evil one.” Although, of course, everything that can break, breaks, and what cannot, gets clogged. This “golden rule” of technology has not been canceled.

So what are the main problems with CVTs? Let's look at the three most common ones.

Problem #1

Most often, the cone bearings in a variator wear out. Such an event will not go unnoticed for the car owner, because it is accompanied by “songs” - more precisely, a hum. It is difficult to confuse this sound with something else. The most offensive thing for the car owner is that the sore can appear even with a “children’s” mileage of 45,000 - 50,000 km.

The ailment can be repaired, but it will cost around 40,000 rubles to pay specialists to replace four bearings and some spare parts.

As statistics show, such surprises are most often presented to Qashqai. In second place is the X-trail, and the Outlander is completely immune to the disease. For the “Japanese”, this problem is relevant only when the mileage exceeds 150,000 km.

There are several reasons why bearings begin to make noise. The most common is the contact of wear products on the working surfaces: only two oil filters and a magnet act as a barrier to them in the unit. Agree, the defense is so-so. Changing the oil every 30,000 - 50,000 kilometers will help extend the life of the bearings. (For example, the Renault-Nissan concern recommends changing the oil in the variator only after reaching the 100,000 mark, and Mitsubishi - every 75,000 km. This makes you think, doesn’t it?) But, as statistics show, even frequent oil changes - not a panacea. The quality of the bearings themselves sometimes raises many questions. And this is strange, considering the cost of repairs.

Problem #2

This problem is hardly inferior to the first one in terms of the scale of troubles. Jerks and twitches are signs of a “nervous tic” in a car, and this is not good. Most likely, the pressure reducing valve of the oil pump decided to “cover itself with a copper basin.”

Valve health problems can be caused by the same wear products. They force the valve to jam in intermediate positions. Because of this, the pressure in the system jumps, the drive and driven pulleys are “lost” - and as a result, the variator belt slips.

If you contact a specialist immediately, damaged pulleys can be corrected by grinding. But the belt will most likely have to be replaced, and this is not cheap - from 60,000 rubles.

If the case is “clinical”, then the budget may be reduced by a good hundred.

Problem #3

This is not even a problem, but a warning. CVTs are very sensitive to temperature conditions. Therefore, special attention is paid to it in the unit. “Greenhouse conditions” are monitored by a self-diagnosis system, assisted by a special temperature sensor.

If the oil temperature creeps up, the system reports this to the electronic “brains”, and they light up a malfunction icon on the dashboard and put the variator into emergency mode.

On many cars equipped with CVT, not only the heat exchanger, but also a special radiator is responsible for maintaining the desired oil temperature. It is located in the front of the car, directly in front of the air conditioner radiator.

This location turned out to be not the best. Dirt and midges make their way through the air ducts in the bumper, and the first thing they do is tightly clog the honeycombs of the variator radiator.

It’s not difficult to understand that it’s time to clean the radiator - the oil begins to overheat even at high speed. Therefore, for prevention, it is necessary to flush the radiator every two years. You can do this yourself - usually just unscrew the bumper. It wouldn't hurt to install a protective mesh in the air ducts either.

The era of CVT is just around the corner

Considering the speed with which CVTs are conquering concerns, the future still belongs to them. In addition, according to statistics, modern CVTs do not fail much more often than their counterparts - classic hydromechanical “automatic machines”.

The coming reign of CVTs is also indicated by the fact that concerns that previously turned up their noses at the mere mention of a continuously variable transmission have turned to their “services.” We are talking about Toyota, which has equipped the restyled RAV4 and Corolla with a CVT. Even the archaic management of Subaru decided to take a similar step: CVTs are now equipped in the Forester, Outback and XV. Who will be next?..

Photo: Mikhail Fomichev/TASS

Smooth ride

The next most common defect occurs in the form of jerking and jerking of the car. The responsibility lies with the pressure reducing valve located in the oil pump.

The latter begins to function when the engine starts. The pump is manufactured as a monolithic unit and in the event of a defect in the pressure relief valve, it must be completely replaced. During normal operation, the valve should move freely in a mating sleeve pressed into the pump housing. Constant contact of the valve working surface with abrasive particles of wear products falling on it leads to the formation of many longitudinal scratches. When worn, the valve begins to jam so much that subsequently it is difficult to pull it out even with pliers.

The result is abnormal pressure, leading to disruption of the coordinated operation of the pulleys. This causes the belt to slip. Timely contacting the service allows you to reduce financial costs. Minor damage to the cones can be corrected by grinding. The belt must be replaced.

The most famous CVT oil sold in car dealerships is the product from Nissan NS-2 in a two-liter tin. The container of the new issue is silver, the old one is painted blue. In no case should it be confused with the old, completely incompatible NS-1 oil, bottled in pink containers.

Extreme enthusiasts who are accustomed to pulling out a stuck car by rocking with instant alternate switching of the lever from position D to R and back run the risk of encountering another problem - unpleasant jolts during the process of switching from the “parking” position to D or R. In this mode, there is practically no pause when switching. between positions D and R, although ideally a complete stop of the car is required. As a result, increased wear of the coupling spline joints inside the planetary gear in contact with the friction discs occurs. The result is the need to replace the planetary gears.

Cleaning the Honda variator control unit (with photos)

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Honda CVT. Cleaning the variator control unit.

Warning!

The operation that will be discussed in this article is, in fact, quite complex, very responsible, and in no way “preventative”! The work, as well as the materials used during the work, can cause harm to the car if used incorrectly or if there is insufficient preparation. A prescription for such actions may be an unambiguous diagnosis of the problem with the variator, while eliminating all other problems with the engine (ignition systems, fuel supply, electrical circuit violations).

It is necessary to perform the operation discussed in this article only in a warm, bright room and with maximum care.

End of warning.

So, today we will talk about cleaning the variator control unit in a Honda. I would like to immediately note that the article will contain instructions for CVTs of the first generation, first and second types (cars, for example, Honda Civic EK3 and Honda Civic EU1). CVTs of the third type (Fit) and subsequent generations cannot be repaired using this article, since they have design differences from the first two types.

A prerequisite for such an operation may be problems with the CVT such as “floating” tachometer speed, “kicks” when starting, “smeared” reaction of the box to engine operation. At the same time, all other problems with the car related to ignition, etc. must be eliminated. Before removing the “brains” of the variator, you need to make sure that the problem is in it, and not, for example, in bad high-voltage wires.

The “model” for today’s article will be the Civic EU1, which came to us with a clear problem with the operation of the variator. In one of our previous articles, we talked about how to change the special fluid in a variator. ⅔ of the actions from that article will have to be done this time. Before removing the “brain”, you will need to drain the special fluid and remove the pan. If you haven’t changed the special fluid for a long time, this would be an excellent reason to do it now. We will accompany further actions with photographs and comments.

Slowly, carefully unscrew the long bolts securing the control unit to the pallet. Since the entire structure is aluminum, no excessive force should be applied. If something won't unscrew or detach, take your time and inspect everything carefully first.

Disconnect and unscrew the wire fastening. Attention! Remember the colors and locations of the chips!

We take out the “brains” from the seat.

The landing site itself looks like this.

If you shine a light bulb, you can see that same variable-speed belt.

Let's break the brain down into its component parts. This is a simple job, but it also requires extreme caution and accuracy - a lot of force is more likely to break the knot than help. “Cutting” should take place in conditions as clean as possible, and it is best to use a clean waffle towel as a lining for the parts.

It is best to lay out the parts in the order they were removed, this will make it easier to put them back together.

In our case, we used the tray as a bath for washing and wiping the elements. Simple and convenient, really.

Through all these channels, which look like a labyrinth, a special fluid moves in the assembled unit. Of course, they will also need to be cleaned, but we are primarily interested in valves that transfer liquid in different directions. One of them is visible in the photograph. It is as if “under” the labyrinth and differs in color. These valves are often the source of problems. The fact is that over time they wear out and begin to jam in the channels in which they should move freely under their own weight. When these jams begin, the box begins to behave inappropriately, jerks, puts an incorrect load on the engine, and so on. Our task is to remove them from their seats and, to begin with, at least inspect them and wipe them from possible dirt.

In order to remove the valve from the channel, you need to remove this bracket. To remove it, we used a homemade awl with a long thin end and a ring instead of a handle.

After removing the bracket, ideally, the valve should fall out of the groove on its own. If it doesn’t fall out, you need to help him.

If the valve was poorly removed and the cylinder walls have unevenness (can only be determined by lubricating the valve well with HMMF and dropping it back), you can carefully clean the cylinder with a sandpaper thoroughly soaked in the same HMMF (CVTF). ATTENTION ! This operation requires minimal effort and time. Do not rub the sandpaper in the cylinder for a long time, or even with any force. The gaps in this unit are counted in microns, so sandpaper is only to remove possible inclusions of harder particles from the surface of the cylinder. This operation in itself is incorrect, so the prescription for it can only be unambiguous wear of the variator. Carrying out this operation on a working variator for “prevention” is IMPOSSIBLE.

There may also be wear on the piston itself, such as in this photo. The elimination method is the same. The warnings are the same as in the previous case.

The block with solenoids (solenoid valves) also contains ordinary valves, which must be movable. The logic is simple: if the valve is movable in its cylinder, we don’t touch it; if its mobility is in doubt, we take it out and clean it. In our case, four valves out of eight on large parts and one on blocks with solenoids were cleaned.

After cleaning the valves, the labyrinth platforms themselves are thoroughly washed with a carbon cleaner to remove all kinds of microcontaminants. Note the small metal mesh in the larger platforms. They contain a lot of dirt, so they must also be thoroughly washed. Now you can start reassembling.

Before installation, the metal plate between the two blocks must be thoroughly washed from dirt (there is a lot of it on it) and immersed in HMMF in order to have an oil film on both sides.

We reassemble in reverse order.

The main thing is to take your time and carefully select the sequence of parts. It's hard enough to make a mistake. Bolts must be tightened carefully. Don't forget that all parts are aluminum.

The entire structure is put into place in the reverse order shown in the first four photographs.

As a conclusion, it can be noted that the question of cleaning or brainwashing the Honda variator is raised quite often on the Internet, but few people know HOW it’s done, and even fewer people know how to do it CORRECTLY. The purpose of our story was to demonstrate the process. It is recommended to do it yourself only by experienced mechanics who understand the full responsibility of this event. The cost of a mistake is high—the variator itself.

If you think that your car needs such an operation, first consult with the experts, and be sure to make sure that the problems of your car stem from the variator and not from other components. Otherwise, such repairs can only do harm.

Those who are ready to take a risk and try to repair the unit themselves can use this material as some kind of instructions for the procedure. But, to be completely honest, it is better to entrust this complex operation to professionals.

PS After disassembling the “brains of the variator” in my own car.

Firstly, the operation is really not for the faint of heart or absent-minded. It is difficult to confuse the design elements, but it is possible if you are distracted for at least a minute halfway through. The valves in CVTs of the first type are not steel, but some kind of titanium, or something similar. Some valves in my car (Honda Capa) were stuck to death, I had to take everything apart and clean it.

Secondly. I made a mistake when connecting the wires and attached them incorrectly. Because of this, the box produced errors 31 and 33 (main line solenoid and emergency mode solenoid). I had to remove and install the brains several times before the cause of the problem was discovered. For those who will repeat, on the one hand, a single wire goes to the small solenoid , on the other, the wire with a green winding should be on the lower solenoid!

Third. The box requires calibration after repair. It can be done with a special scanner, but, as they say, for lack of anything better, you can try to do it on the go. I had to do exactly the second scenario. The essence of the calibration is as follows: a fully warmed up car is driven onto a flat straight road, parked, then switches to D and accelerates to 60 km/h (I managed to do this on the third attempt, because twice the car simply stalled at speed), and at 60 km/h the gas is sharply released so that the car starts to coast. In this case, all energy consumers turned off (stove, lights, music, heating, heating, etc.). In winter, doing all this is extremely inconvenient (especially at a temperature of -36 in Novosibirsk), but there was not much choice. The coasting movement should take at least 6-7 seconds! Do not press the gas or brake at this moment! After this, you can try to press the gas on the car. If a kick occurs, the calibration is repeated.

Fourthly. Yesterday's first trip was very difficult - the car stalled, went into emergency mode several times with D blinking and the transmission locking. The second trip was already better. The third, the road home, is even better. The car no longer stalled or tried, it accelerated confidently up to 70 (it was scary to accelerate further, since there was a high probability of sending the transmission into emergency mode at this speed), although there were spreading kicks when releasing the gas and pressing it again, almost with every press. This morning, on the way to work, the situation improved even more, there were fewer kicks, and acceleration and maneuvers in the car began to seem safe already at 80-85 without attempts to go into emergency mode. Climbing a steep hill also did not cause any problems (and yesterday, during the first climb up the mountain, according to the law of meanness, the box went into emergency mode right on the tram tracks, and before I realized that I needed to “reboot” (turn off and turn on the ignition) passengers on two trams pushed me off the rails.

In general, the experiment continues.

PPS 03/20/2012 The variator is much better than it was before the repair. It’s somewhat difficult to call his work “ideal” (after all, a lot of mileage is a lot of mileage), but the fact that it has become better than it was is a fact. The situation returned to normal after 250 km after repair.

PPPS 05/05/2013 Now the variator is doing very well - it is sitting in a warehouse and waiting to be sold as a whole, or for spare parts.