How to check an automatic transmission when buying a car

Checking the operation of the automatic transmission – Automobile magazine AutoMPV.Ru

Checking the operation of the automatic transmission

Automatic transmissions have become much more reliable, but still remain the most vulnerable component of a car.

What's the matter? Checking the operation of the automatic transmission

Modern technology is becoming more and more complicated, and we often use it with little idea of what’s inside.

However, it is not difficult to guess that wear of one of tens or hundreds of parts is the path, first to fuzzy operation, and then to failure of the entire unit. Everything said fully applies to the automatic transmission.

It has many precision pistons. As soon as one of them stalls, the transmission stops working correctly.

The automatic transmission is sensitive to overheating of the transmission oil - if you skid in deep snow for 20-30 minutes, it is very possible to burn the box (there is a known case with an Audi on the day of purchase - the repair cost $2000, and it only lasted for a year).

By the way, the wrong type of oil and its poor quality will more than quickly (within half an hour) lead to breakdown. Many working parts of the machine wear out naturally. There is a magnet in the oil pan that attracts metal powder. Even after 150 thousand.

km it will be covered with a thick layer of metallic plaque. Test the same magnet on the manual transmission and it will be completely clean after a similar mileage.

In addition, machines rarely work for a long time after repair - they have too many precise parts, and the slightest mistake or speck causes a breakdown again.

Therefore, the automatic machine, with all its reliability, requires especially careful attention when buying a used car. Otherwise, breakdowns cannot be avoided. And this leads to expensive (and complicated!) repairs.

What should you pay attention to when testing a machine when buying a used car? Naturally, we turn to a professional to test a used machine.

The main thing is to check, as far as possible, the history of the car. This saves money and time. If the car was used at a car rental place or was restored after a serious accident, pass by. Ask the seller or previous owner if the machine has been repaired. If yes, it's better to look for something else.

The reason here is not the fact of the repair itself - some machines work better than before the repair. However, not all repair shops can repair automatic transmissions professionally. But the quality of the repair is impossible to determine.

Another reason for attention is the presence of a towbar, since transporting a trailer causes additional wear on the automatic transmission.

Checking the operation of the automatic transmission - how to do it?

Let's start by checking the oil level in the machine and its condition. The engine is idling, the automatic transmission is in the “Park” position. Remove the transmission dipstick and wipe it with a clean cloth. Insert it back and pull the dipstick out again. Look closely at the oil. Wipe the dipstick with white paper.

The mark on the paper should be clean and transparent without any metal particles or foreign flakes. New oil is usually red. It will turn a little brownish over time, but should not be black. Smell the oil. There should be no burnt smell. As you can see, there is nothing complicated in this check.

So, if the oil of the machine is too dark, has metal particles or smells like burning, then it is better not to buy such a machine. True, many modern automatic machines do not come with an oil dipstick, and checking the oil level is only possible in a specialized technical center. In this case, only a test drive remains to control the machine.

How to do it? Since the car is not yours yet, be careful and attentive. Adjust the seat, mirrors, check the brakes. The first sign of a defective automatic transmission is the delay between the moment you select gear D (Drive) or R (Reverse) and the gear is engaged. Warm up the car slightly with the transmission in P (park) until the rpm drops to 650-850 rpm.

Foot on the brake pedal, switch to D (Drive). The automatic transmission should immediately select this mode - it feels like it begins to “drag” the car forward. The switching process should occur smoothly, without jolts or knocks. Switch to N (Neutral) - the box should turn off. Now turn on R (Reverse).

Again, the automatic machine should turn on instantly, and you will feel that the car wants to crawl back. And in this case there should be no shocks or knocks. Now, while holding the brake, shift from D to R and back. Again the process should proceed without any jolts or knocks.

If there is a delay of more than 1 second when the gear is engaged, then the box is either worn out or already requires repair.

Checking the operation of the automatic transmission in motion

With the automatic transmission lever in position D (Drive), take your foot off the brake and gently accelerate. Up to a speed of 50-60 km/h, gears must be switched at least twice (from first to second, from second to third). All switching should be soft, without shocks or delays.

The moment of gear shifting is determined by a slight change in the engine noise level and a drop in its speed.
If the automatic transmission is excessively worn, then the gear shifts with a push or delay and even a blow (especially when switching from first to second). At a speed of 40-50 km/h, press the gas all the way, a fully functional automatic transmission will shift to a lower gear and the speed will increase.

Next, check overdrive (if any). This is the button to the left of the automatic transmission lever in Japanese and American cars. At a speed of 60-70 km/h on a flat road, switch to ON mode by pressing the “Overdrive” button. The automatic transmission should shift into an up gear. Shift to OFF, the automatic will go down one gear.

Another problem with the automatic transmission is gear slipping. This is a situation when you press on the gas, the speed increases, but the speed does not increase.

Even one of these defects is enough to stop buying a car.
Don't rush to finish your test drive. It may happen that defects in the automatic transmission appear only when it is warmed up (or, conversely, disappear after warming up).

Time spent on meticulous checking will result in fewer problems in the future. A fully serviceable gearbox that is in working order does not jerk, does not knock, does not slip or make noise when shifting at any speed and at any oil temperature.

If they begin to assure you that noises, knocks and similar phenomena are common and natural for this model, it is better to refuse such a purchase.

If the check engine light (overdrive flashing) appears during a test drive, discuss the problem with a reliable technician you completely trust.

Watch Toyota's instructional video about automatic transmission:

Video : correct use of an automatic transmission:

Video : checking the automatic transmission when buying a car:

Source: http://AutoMpv.ru/sovety/806-proverka-rabotyi-akpp.html

How to check the automatic transmission yourself

Category: Secrets of choosing and purchasing | Published date: June 9, 2016 | no comments

Buying your own car is the dream of many residents of our large country.

Many people prefer cars with a manual transmission, but those who appreciate comfort always choose an automatic transmission.

How to avoid making a mistake when choosing a vehicle with an automatic transmission? How to check the automatic transmission before purchasing so as not to regret the money spent on the car?

Checking the box - "automatic"

You will have to find a flat area to park the car. Then, while sitting behind the wheel, you need to turn it all the way in any direction and engage first gear. Now you need to release the brake pedal without touching the gas pedal, after which the car should move off.

If the car could not move, then the automatic transmission is hopelessly broken and it simply does not have enough power to move the vehicle. Of course, you shouldn’t make a diagnosis from the first test. To confirm your guesses, you need to repeat the procedure with the steering wheel turned completely to the right and left, and then in reverse.

Next, you need to check the operation of the first and second gears of the automatic transmission. To do this, when you get behind the wheel, you need to turn on D i.e. forward position. Press the brake pedal firmly and try to press the gas all the way with your right foot.

When pressing both pedals at the same time, you should pay special attention to the tachometer readings, where numbers from 2600 to 3000 rpm should appear. In this case, the instrument needle should not move or twitch. This procedure should last no more than 10 seconds, and the ideal tachometer reading would be 2700 rpm.

3000 rpm is the maximum tachometer indicator for a working box, while the arrow on the device should remain frozen.

Checking the serviceability of CV joints

With the steering wheel fully turned, you need to depress the gas pedal, and if you hear clicks or crunching sounds from the front, then the automatic transmission is faulty. You can without hesitation refuse to purchase this car or bargain with the seller for a lower price. This method will not harm the automatic transmission, but will help the buyer avoid unscrupulous sellers.

Read Tips and tricks for selling a car

If the above check showed good results, then you need to test the car in motion. The car must be accelerated on a flat road, squeezing the gas pedal to the limit. In this case, you need to monitor the number of engine revolutions, not paying attention to the gear engaged. The revolutions should not float! There can be no jerking, clicking or extraneous noise!

When shifting from third to fourth gear, a slight jolt should be felt - this is normal. Here you need to check how the car brakes and whether it pulls to the side. In this case, you need to brake sharply, and if the vehicle begins to deviate from its trajectory, then there are no problems with the brakes.

At the end of testing, you need to try to move off in all gears in turn. Shifting of the automatic transmission should be smooth, without jerks or shocks.

How to check the oil in an automatic transmission

The oil dipstick makes it possible to carry out initial diagnostics of the automatic transmission. First of all, you need to check the oil level, and then wipe the dipstick with a clean cloth and pay attention to the remaining mark. If the color of the oil has a reddish or yellowish tint, then everything is normal. If the color of the oil is black or dark brown, then there is no need to purchase such a machine.

When choosing a car with an automatic transmission, you need to be extremely careful and if anything is in doubt, then it is better to refuse such a car.

Source: http://drivedrom.ru/sekrety-vybora-i-pokupki/kak-proverit-korobku-avtomat-samostoyatelno.html

How to check an automatic transmission when buying a car

Buying a used car with an automatic transmission must be done responsibly. In this matter, it is important not to make a hasty decision, but to carefully check the operation of the automatic transmission.

If you decide to buy a car with an automatic transmission, then you need to know how to identify possible defects. This article will help with this. It describes several methods that are best applied sequentially. You should always start checking with oil.

Checking the automatic transmission oil

It is convenient to assess the condition of the transmission fluid using a dipstick. But not all machines have a design equipped with a probe. To check the oil in such a box, go with the seller to a service station. The specialist will conduct a full diagnosis and tell you exactly what condition the automatic transmission is in.

If the box has a dipstick, then you can check its fluid yourself. This must be done in parking mode (P) and with the engine running. While the engine is running, you need to remove the dipstick from the box, wipe it with a cloth and put it back in place. Then pull it out again and look at the level, color, smell the smell.

Checking automatic transmission gear shifting

After making sure the oil is in good condition, get into the car and check the gear shift. This should be done after the engine has warmed up. Apply the brake before changing gears. Watch and listen carefully to the operation of the machine. Evaluate the smoothness of switching and make sure there are no jerks, jolts or delays.

Smoothness. To check this parameter, move the lever. First, engage reverse gear, then neutral and drive mode. The first time, move the lever slowly through all gears. And in the second, repeat the switching, but at an accelerated pace.
Jerks, jolts, delays. A machine with defects will display its condition during operation. When changing gears, you should not feel any jerking or jolting. Please also note the delay. In a working automatic transmission, the gears engage quickly.

If the delay lasts more than one second, this is a sign of wear on the box.

Conducting a “Stall speed test”

Stall speed test - carried out after the engine has warmed up to operating temperature. The test helps to identify transmission defects in drive (D) and reverse (R) modes. During the test, the number of maximum engine speeds with the wheels locked and the throttle fully open is determined. These values can be used to judge the condition of the automatic transmission.

Test results differ for different car brands. Specific values are indicated in the machine’s service book. If you want to carry out a test, keep in mind that it forces the machine to work at its limit. But the stall speed test is safe and will not harm the box under the following conditions:

the duration of the test should not exceed five seconds;
The machine is initially in good condition.

Therefore, before testing the automatic transmission, ask the seller for permission. Refusal can be regarded as uncertainty that the machine will pass the test. And if he gives his consent, adhere to the technique described below.

Test technique

Warm up the engine to 90–100 degrees Celsius.
Block the wheels completely, to do this, install wheel chocks, raise the handbrake and press the brake pedal.
Switch the automatic transmission lever to drive mode (D).
Press the gas pedal to the floor for five seconds.
Look at the tachometer and note the number of revolutions shown in the last second.
Move the automatic transmission lever to the neutral position (N) and release the brake pedal.
Check the result with the values indicated in the technical book of this car.

The same testing must be done in reverse gear (R). But first, take a break for a few minutes to allow the oil in the box to cool. To do this, let the engine idle.

If the test values are less than normal, this indicates a poor condition of the engine, which cannot develop sufficient power.
If the test result exceeds the permissible speed limits, this indicates worn out clutches of the front and reverse gears.

Checking the automatic transmission while driving

Having carried out the preliminary checks described above, proceed to testing the box in motion. Offer the seller a ride. Find a safe and spacious area where there is not a lot of traffic. While driving, check several operating modes of the machine:

Smooth acceleration. Accelerate smoothly to 60 km/h. While the car picks up this speed, the automatic transmission must switch at least twice. If this does not happen, then the box has problems.
Sharp acceleration. Pay attention to the acceleration dynamics.

If the engine speed is high, but the car slowly picks up speed, it means the transmission is slipping. A car with a working automatic transmission accelerates quickly and without jerking.
Sharp braking. After accelerating, apply sharp braking. If the box is working properly, then the speeds will quickly drop from fourth to first.

At the same time, jerks and delays should not be felt.
Enable OverDrive mode. Accelerate to 70 km/h. At this speed, the automatic transmission will engage fourth gear. Press the OverDrive button, the machine should go into low gear mode, i.e., reduce the speed one step lower.

If this does not happen, then the box again has problems.

Now you know how to check the automatic transmission yourself before buying a car. The methods described above will help determine the general condition of the box and save a decent amount in the future. The main thing is, don’t be lazy to use them and then you will find the car that won’t let you down.

Video: how to independently determine the condition of the automatic transmission

Source: http://car-hz.ru/sovety/avto-stati/6245-kak-proverit-korobku-avtomat-pri-pokupke-avtomobilya

How to check the automatic transmission when buying a used car? (step by step instructions with video)

Good afternoon. As you may have guessed from the title, in this article I will tell you how to check the automatic transmission when buying a used car. The article is a video and its text description.

First automatic transmission check - Stall speed Test (stop test)

This is the most universal test that shows the general condition of an automatic transmission. This test allows you to determine the wear of the clutches in the box, as well as the condition of the oil and donut (torque converter).

The test procedure is as follows:

We warm up the engine and gearbox, for this we drive 10 - 15 km.
We place the car on a horizontal platform.
With your left foot, press the brake pedal all the way.
Move the automatic transmission selector to position D (drive).
With our right foot, we sharply press the gas pedal to the floor for five seconds, while looking at the tachometer, we are interested in the maximum speed that will be achieved by the engine (as soon as the speed has stopped increasing, the test can be stopped).

In no case should you hold the car with the brake in gas to floor mode for more than 5 seconds, since the gearbox is working in heavy duty at this time.

For most cars, when performing a stop test, the speed will be set in the range from 2000 to 3000. Moreover, the transmissions of 70% of cars are designed so that the speed test shows 2200 revolutions.

If, as a result of the test, the engine does not spin up more than 2000 rpm, then the engine itself is probably faulty - it is not developing full power.

If the engine does not spin above 1500 rpm, the automatic transmission “donut” is probably faulty, or the oil in the box has not been changed for a very long time.

If the engine speed exceeds 3000, the clutches of the automatic transmission are probably faulty, and it is living its last days.

In any case, a car that does not pass this test well is not worth purchasing.

Exceptions to this test are tuning cars. Some companies specially modify the automatic transmission donut so as to increase the maximum speed, this is done for more intense acceleration, but has a negative impact on the service life of the transmission. Personally, I highly doubt that a person who buys tuning cars will read this article.

Second check - start of movement

The check is carried out as follows - we stop the car on a horizontal section of the road, press the brake, put the selector in position D, release the brake, while not touching the gas pedal, as a result the car should start moving. We do exactly the same check in position R (reverse).

If the car starts to move, this indicates wear on the clutches in the gearbox; replacing them is expensive.

Third check - acceleration and braking

The verification method is as follows: we start driving by pressing the gas pedal by about 30%, while the car should slowly and without bumps or jerks pick up speed. In this mode, it is advisable to wait for all gears to shift sequentially.

After waiting for the last gear to engage, we also smoothly stop the car by coasting, and all gears should sequentially engage in the opposite direction.

The next check is carried out according to exactly the same scheme, only the gas pedal should be pressed two-thirds. In this case, acceleration is carried out with greater intensity. In this case, there should not be strong kicks, but transmission shifts can be felt.

Fourth check - kickdown

This check is carried out as follows: the car is moving at a speed of 70-90 km/h, the gas pedal is pressed sharply, until it hits the floor.

The automatic transmission should drop one or two gears down, that is, switch to third or fourth gear, the engine speed should increase sharply, and at the same time intense acceleration should begin.

Fifth check - oil check

If the car is equipped with a service dipstick, take it out, check the oil level; it should be between the minimum and maximum marks depending on the temperature: on cold, 25 degrees, respectively, on hot, 80. We look at the oil; there should be no crumbs in it and there should be no smell from it burning.

Sixth check - checking for oil leaks

The last check of the gearbox is carried out under the car in a pit - we inspect the box from below for leaks of gaskets, seals and plugs.

This is where checking the automatic transmission ends; check without opening anything else.

To illustrate how the automatic transmission is checked, I recorded this video:

It is important to understand that automatic transmission malfunctions are usually very expensive to fix, and in most cases are solved by replacing the automatic transmission with a contract one. Therefore, if you have any doubts about the serviceability of the box, it is better to refuse to buy a car, or ask for a discount on a contract box.

That's all for me today. I hope that you understand how the automatic transmission on a car is checked. Smooth roads and reliable transmissions to everyone. If you have any questions, ask in the comments….

Sincerely, administrator http://life-with-cars.ru

Source: http://life-with-cars.ru/pokupka-avtomobilya/proverka-tehnicheskoj-chasti/kak-proverit-akpp-pri-pokupke-poderzhannogo-avto-poshagovaya-instruktsiya-s-video/

How to check the automatic transmission when buying a used car

Sooner or later, a motorist is faced with the choice of whether to buy a car with an automatic transmission or not. And if you decide to buy a used one, but with an automatic transmission, then this option needs to be thoroughly checked. The thing is that automatic machines of early releases, for example right-hand drive Japanese ones, are quite a vulnerable point of the car.

That is, the structure of the automatic transmission itself is quite strong, but if your car is 10 years old and you are no longer the first owner, then God knows how it was used. And the cost of repairing such a transmission will simply go through the roof! So, approach your purchase wisely; in fact, today I’ll give you some useful tips + a detailed video.

It will be interesting, I promise...

Yes, it’s better to test the automatic transmission than to pay for expensive repairs later. Today I want to give you some tips so as not to end up with that very difficult repair.

But it’s really expensive, let’s take the Moscow region as an example - the average cost of repairing a machine is approximately 10,000 - 15,000 rubles and this is only work (that is, it’s trivial to remove, disassemble and put back), but you also need to add the cost of spare parts, this will add even more 30 – 40,000 rubles.

Total 40,000 - 55,000 rubles, on average, of course, repairs can be much more expensive if you have an expensive foreign car. Do you need it? So we check carefully before purchasing.

I would also like to note that if you don’t “fumble” with the automatic transmission at all, then I STRONGLY RECOMMEND you to GO TO AN OFFICIAL service station, let them check there (oil, work in general) - look at the condition, read the errors in the ECU. Give 500 - 700 rubles for diagnostics, don’t skimp. This will give a great chance to get a full-fledged automatic transmission, and not junk.

Well, okay, let’s imagine that you don’t have the money to get it checked at a service station or you’re just “choking on a toad,” so we’ll check it ourselves, and almost anyone can do it. Below there are several points that will help you determine the performance of the automatic transmission by almost 80%.

Conversation with the seller

What you should find out:

This is service. Ask how he cared for the automatic, whether he changed the oil, how he did it (with a filter or not). At what mileage did I change it? Where the money changer is, there are “work orders”, etc. If you changed it at an official service station, say after 40 - 50,000 kilometers, and even changed the filter, then there is a high probability that the automatic transmission is alive, because many manufacturers have a replacement interval of 60,000 km. But if, after a mileage of 70 - 90,000 km, the oil has not been changed, and the owner says, “My oil doesn’t change, my automatic is not serviced,” personally, I would think about buying it! THERE ARE NO MAINTENANCE-FREE MACHINES! These are just tricks of marketers, already in 100 - 110,000 km, MOST LIKELY, such an automatic machine will fail, the clutches will simply burn out, or something even more complicated.
We ask a question about repairs. Maybe the seller has already repaired it. This is not always bad, sometimes there are cases where the repaired version worked better than the new one, but this is only if the technical station is serious and provides a guarantee for its services. That is, there must be “work order” documents, a warranty card and a receipt. Then “you can trust the repair.” But if it happened at I don’t understand which station “at Uncle Vasya’s”, and the seller hesitates, it’s better to immediately refuse this purchase. Because the repair of the machine will most likely have to be repeated.

To be honest, when the seller reacts to these two questions, you can already understand whether everything is good with the box or not! This is a preliminary check, but it is required! Sometimes there is no need to go inside anymore.

Oil check

Let’s say there were no repairs and the seller assures that “everything is fine”, changed the oil and took care of it.

Then we start the car in P “Park” mode Then we turn off the car and go under the hood, if there is an oil dipstick , great! Let's take it out and look:

To the oil level . It should be at a normal level, if below the critical level it is bad! Oil starvation of an automatic transmission also does not bring anything good!
On the condition of the oil . If it's dark, it's not always bad, it just worked and "absorbed" all the dirt. However, it should not contain any fibers or shavings. These are already extreme signs of wear. Therefore, we wipe the dipstick on a cloth or, better yet, on a clean sheet of paper and examine this mark. If there are no third-party products, only oil, then good. But if the oil is also fresh - transparent, in automatic transmissions it is usually pinkish - reddish in color, this is actually even better. True, if it doesn’t smell “burnt.”

The smell of oil . A very important procedure, the whole point is that the automatic transmission has so-called “clutches” (friction discs) in its structure, this is a kind of analogue of the clutch. Due to untimely oil changes, they can “burn” (I won’t go into the building now, read the link above), and this simply makes the oil “smell burnt.” If you pull out the dipstick and it just “reeks” of a burning smell, FORGET ABOUT THIS CAR! This is a 100% renovation! If there is no dipstick, it’s supposedly a “maintenance-free machine,” then we simply unscrew the filler cap from the top and smell it - it also comes into contact with the oil in the machine, and also either smells “burnt” or not.

If everything is fine, then you should move on to checking the automatic switching.

Checking while the car is standing

Now we need to play around with shifting gears while the car is standing, and again, always warmed up.

In general, the process is like this - we need to switch different modes in different ways:

Start slowly, stopping in each gear for 5-10 seconds.
Then quickly, stopping for a second in each gear.

This process is done with the brake pedal pressed, so that the car does not roll either backwards or forwards.

What becomes clear during this process is that we need to eliminate “strong” shocks when changing gears. There will definitely be small, barely noticeable ones, this tells us that the gears are being engaged, they will be especially felt in mode D - “Drive” and R - “Reverse”. But if the shocks are strong, such that the car is being pushed - THIS IS NOT NORMAL! This car is not worth taking.

Check while driving

We checked it on the spot, now we need to check it on the move. ON a warmed up car, to operating condition, the engine speed should drop to 800 - 900 per minute. It is best to check on a long, level place where you can accelerate to 60 - 90 km/h.

Here you can break down the automatic transmission check into three stages:

Smooth and quiet ride, with a gradual increase to 60 - 90 km/h (depending on where you check).
A sharp start from a standing start.
Downshifting

Now a little more detail.

Smooth ride from standstill . Everything is simple here - from mode P “Parking”, switch to mode D “Drive”. And we gradually begin to accelerate, that is, we check the “gentle” mode. The automatic transmission should change gears, you will understand this from the tachometer, with slight jolts when shifting.

At 90 km/h, on a 4-speed automatic, the tachometer will show approximately 2500 - 3000 revolutions, on a 6-speed automatic, about 2000 revolutions. It is also advisable to look at the dashboard and make sure that the maximum gear is engaged, that is, 4 or 6 depending on the design.

If on a 6-speed automatic transmission you have 3000 - 3500 rpm, but the “sixth” does not turn on, then there is something wrong with the box!

If the automatic transmission operates normally in this mode, proceed to the next test.

A sharp start from a standing start . Actually, everything is simple here, you need to stop, put the box in “drive” mode and sharply press the gas pedal. The car should immediately accelerate, the revolutions will soar to 5 - 6 thousand. The dynamics must correspond to those declared by the manufacturer. That is, if you indicate 10 - 12 seconds to 100 km/h, approximately these figures should be.

The second speed test, the purchased car passed, which means the last one is final.

Downshifting . Everything is also simple here, we check how the gearbox downshifts. Many people neglect this test when purchasing, but I believe that it is mandatory! We accelerate the car to 90 km/h, and then simply remove the gas pedal, the car rolls and should gradually lower gears. This should happen softly, barely noticeable!

That's all there is to it. If you go through all the points when buying a used car, and the transmission holds up to everything, then 80 - 90% of it is normal.

I would also advise you to lift the car on a lift and see that there are no leaks from the automatic transmission anywhere! It should not leak, otherwise the oil will leak out and cause death.

Now the video version of the article is INTERESTING, so watch it.

Source

Source: https://4kolesa.mirtesen.ru/blog/43814213599

Checking the serviceability of the automatic transmission | Motorist's benefit

If you were to see how an automatic transmission works and imagine that wear of one of the many parts and seals leads to incorrect operation of the entire unit, the answer would become obvious. Automatic transmissions are also sensitive to overheating of the transmission oil - if you get into deep snow and skid in place for 20-30 minutes, it will be enough to burn the transmission.

There are plenty of examples of this. The machine has many precision pistons. As soon as one of them stalls, the transmission stops working correctly. Many working parts of the machine are subject to natural wear and tear. There is a magnet in the oil pan that attracts metal powder. Even after 150,000 km it will be covered with a thick layer of metallic deposits.

Test the same magnet on the manual transmission and it will be completely clean after a similar mileage. In addition, machines rarely last long after repair - they have too many precision parts, and the slightest mistake or grain of dirt causes a breakdown again.

From all of the above, we conclude: an automatic machine is a unit that requires especially careful attention when buying a used car.

Yes, machines have become more reliable today, but they still remain the most vulnerable and prone to breakdowns, followed by complex and expensive repairs.

If used incorrectly, the machine can be destroyed in half an hour.
One client tried to free his brand new Audi from a snowdrift and burned the box on the first day of purchase! The repair cost $2,000, and a year later the box broke again. The automatic transmission is highly dependent on the quality of the transmission oil and its condition. The wrong type of oil can lead to breakdown within half an hour.

Let's try to consider what you need to pay attention to when testing an automatic machine when buying a used car. Additionally, we highly recommend having a professional test your used machine - a very smart investment.

First, check the car's history if possible. You will save time and money. If the car's history suggests it was a rental car or was restored from a serious accident, don't even look at it. Ask the seller or previous owner if the machine has been repaired. If the machine has already been rebuilt, it is better not to buy such a machine.

It's not that all rebuild transmissions have problems - some run better than they did before the rebuild. The problem is that not all repair shops are able to properly repair automatic transmissions. And since it is impossible to determine how high-quality the repair was, it is better to abandon such a car altogether. Another reason to worry is the presence of a tow bar.

Transporting a trailer causes additional wear on the automatic transmission and the check light comes on.

How to check the automatic machine of a used car

First, check the oil level in the machine and its condition. The engine is idling, the automatic transmission is in the “Park” position. Remove the transmission dipstick and wipe it with a clean rag. Insert it back and pull the dipstick out again. Look closely at the oil.

Wipe the dipstick with white paper to assess the condition of the oil. The mark on the paper should be clean and transparent without any metal particles or foreign flakes. New oil is usually red. It will turn a little brownish over time, but should not be black.

Smell the oil. There should be no burnt smell. At first this check will seem difficult, but after several cars, you will understand that there is nothing complicated here.

So, if you find that the oil of your machine is too dark, has metal particles or smells like burning, then it is better not to buy such a machine.

Keep in mind that many modern automatic machines do not come with an oil dipstick, and checking the oil level is only possible in a specialized technical center. In this case, only a test drive remains to control the machine.

Test drive to check the machine Be extremely careful when driving someone else's car. Pre-adjust the seat and mirrors, check the brakes. The first sign of a defective automatic transmission is the delay between the moment you select gear “D” (Drive) or “R” (Reverse) and the gear is engaged.

Warm up the car slightly with the transmission in “P” (park) until the speed drops to 650 - 850 /min. Foot on the brake pedal, switch to “D” (Drive). The automatic transmission should immediately select this mode - it feels like it begins to pull the car forward.

The switching process should occur smoothly without jolts or knocks. Switch to "N" (Neutral) and the box should turn off. Now turn on "R" (Reverse). Again, the automatic machine should turn on instantly - you feel that the car wants to crawl back. Again there should be no jolts or knocks.

Now, while holding the brake, shift from D to R and back. Again no jolts or knocks.

If there is a delay of more than 1 second when the gear is engaged, then the box is either worn out or already requires repair.

Now you need to drive the automatic transmission lever in position “D” (Drive), remove your foot from the brake and gently accelerate. Up to a speed of 50-60 km/h, gears must be switched at least twice (from first to second, from second to third).

All shifts should be smooth without jolts or delays.

The moment of gear shifting is determined by a slight change in the engine noise level and a drop in its speed.
If the automatic transmission is excessively worn, then it shifts with a push or delay and even a blow (especially from 1st to 2nd). At a speed of 40-50 km/h, press the gas all the way, if the condition is correct, the automatic transmission will shift to a lower gear and the speed will increase.

Next: check overdrive (if available). This button is on the left side of the automatic transmission lever for Japanese and American cars. At a speed of 60-70 km/h on a flat road, switch to ON mode by pressing the overdrive button. The automatic transmission should shift into an up gear. Shift to the “OFF” position, the machine will go down one gear.

Another problem with the automatic transmission is gear slipping. You press on the gas, the revs rise, but the speed does not increase. automatic transmission diagnostics

Even one of the above mentioned shortcomings is enough to refuse to buy a car.
The test drive should be as long as possible. Often boxes work normally when cold, but when warm they start to go on strike and vice versa. Therefore, it is better to spend more time checking than to deal with serious repairs later.

A working gearbox does not jerk, does not knock, does not slip and does not make noise when shifting at any speed and at any oil temperature. If the seller begins to assure you that shocks, vibrations and the like are “common” for this car because it has not warmed up or something like that, do not trust him.

If the check engine or overdrive light appears during the test, discuss the problem with your mechanic.

Source

Source: https://sanekua.ru/proveryaem-ispravnost-akpp/

How to check the automatic transmission when buying a used car?

First of all, you need to determine what type of inspection will be carried out, independent or specialized at a service station? It is difficult to find intelligent specialists who can diagnose the “box” using a computer and visually, tactilely. Therefore, we will consider the features of checking the automatic transmission yourself.

How to check?

Diagnostics will consist of stages, including both diagnostics and the study of the “life” of the car as a whole. So:

1. Let’s find out the history of the “life” of the machine, how it was operated. In general, here it is necessary to pay attention to the most banal “little things”, whether the oil in the automatic transmission was changed, what was filled, how many owners, mileage, who drove, where they mostly drove, etc. Study the service book in more detail.

Find out from the seller what kind of repairs were carried out; perhaps the “box” on the car was replaced, for example, with a contract automatic transmission or a hand-made one. It would be nice to have evidence, marks in the service book, receipts.

It’s good if the car was imported from Europe, it’s very difficult to find illegal service stations there, the likelihood that it was serviced by “officials” and notes were made in the book is high.

An example of an automatic transmission oil change record

We do not recommend buying cars after a taxi or an accident, even if the seller admitted and certified that good repairs and maintenance were carried out. As a rule, resale is carried out by “resellers” or owners who, after the accident, invested a taxi, a minimum of funds to simply “sell off” it.

2. The second thing you don’t forget to do is be sure to check the level and condition of the oil. Often, reddish-colored oil is poured into the “boxed” section. It is better to check the level on as smooth surfaces as possible.

Toyota automatic transmission oil dipstick. The level is above normal. Should be at the Hot level on a warm car.

You need to know that some manufacturers allow you to check the level, as for an engine, without the need to warm up.

In such cases, instead of two stripes, there will be four on the “dipstick”. But, remember, this format for checking the oil when it is “cold” is not reliable; it is better to take measurements when it is “hot”, and for this the car must be driven for at least 10 km.

In general, remember that the level should be between the upper and lower marks in both cases. Sometimes corresponding marks are placed with words such as COOL and HOT, corresponding to “which” oil to measure, cold or hot.

In addition, do not forget to clean the oil from the dipstick before checking, that is, the scale should be clean, then insert it back into the crankcase, remove it and analyze the level.

On some models there are no “dipsticks”; instead, control plugs are installed, or there is nothing at all. An excellent example, most Mercedes “boxes” have a valve in the crankcase that regulates the required volume of oil; no checking is required, it is important to check the driving performance.

In addition to the level, pay attention to the smell; if even minimal “shades” of burntness are felt, then it is better not to buy a car, most likely the wear of internal parts is approaching a critical level.

Inspect the oil for color; shades should range from reddish to light brown.

Check for the presence of metal particles, it’s easy to do, take white paper, “send” a few drops from the probe onto it and see if there are any chips left there.

3. Diagnostics of the correctness of switching is carried out on a warmed-up car. Depending on the model and year of manufacture of the machine, signs of proper operation may differ. On modern gearboxes, the presence of jerks, impacts, clicks, and jolts is not acceptable.

For old cars, in most cases, this type of work is, on the contrary, common. The same situation occurs when switching modes “D” and “R”; a slight vibration is felt; this is normal in old automatic transmissions. What is not normal for an automatic transmission is a delay of 1 second or more in engaging the gear.

There is a delay, which means there are some malfunctions, a more detailed check is needed.

In general, you are looking for a unit with fewer impacts, knocks, and jolts.

Checking operating modes:

• Sharp acceleration while driving. For example, if you were driving at 4, when you sharply press the accelerator, the speed will switch to a mode, below - 1,2 and 3, depending on the modification.

• After acceleration, press the brake sharply, the automatic transmission should turn on 1 without any delay.

• When accelerating to 60 km/h, the position will change at least twice, that is, 1-2, 2-3. If there are small jerks, do not worry, this is acceptable for the “box”, except for the most modern ones.

• The next moment, slipping. Found on most used cars. It is difficult to detect slippage, especially for non-masters. Please note that if the speed increases, the pedal goes down, but the car does not move, that is the same slippage. Depending on wear, the delay is up to a couple of tens of seconds, this is already clearly noticeable. A 1-2 second freeze is extremely difficult to detect.

There is also a so-called parking test. It should be used after the above steps have not revealed any malfunctions. So:

• Warm up the gearbox, block the wheels, use the stops and the handbrake.

• Start the engine and apply the brake as much as possible, holding it until the end of the procedure. During this, move the lever to position “D” and press the gas for a maximum of 5 seconds.

• We look at the tachometer at this time; with the engine and gearbox running normally, the speed will not rise above 2,500 rpm.

If the values are higher, then there is some kind of malfunction, probably even in the electronics.
The same can be done with reverse speed.

A special situation arises when choosing a car equipped with a tow bar. After all, the seller will never admit the actual conditions in which the car was used. In principle, trailers are not dangerous for automatic transmissions, but only if you follow the manufacturer’s recommendations for loading.

In this case, serious malfunctions can be avoided. However, if the permissible weight is exceeded, the impact on the “box” is enormous. You can find out more about the requirements for gearboxes from the official manufacturer.

In general, the “box” must be designed for appropriate loads.

Also, do not forget that there are different types of trailers, there are options with their own braking system, and there are simpler and cheaper ones (the majority of them). So, for those towed devices that have their own braking system, the load can be increased, but it is still better to rely on the recommendations of the “box” manufacturer itself.

Conclusion

In general, it is clear that during normal operation there should not be any serious knocks, jolts, or impacts. The main thing is that there is correspondence between acceleration and pressing the gas pedal.