Are you tired of uncomfortable mechanical box gears of your car? Do you want a more comfortable ride? Now it is clear why you are reading this article - you still decided to buy a car with an automatic transmission. Great choice!
The choice of a used car with automatic transmission must be approached wisely. If you want the automatic transmission of your car to serve for many years, then you simply must heed the advice of experienced mechanics.
Checking the level and condition of the oil in the automatic transmission
First of all, when inspecting the car, you need to check the oil level in the automatic transmission. The oil level in the automatic transmission in most cars is controlled using a dipstick inserted into the filler tube. On the probe, as a rule, there are several marks. To fully warm up the automatic transmission, you need to drive 15-20 km. Checking the oil level should be carried out on a flat horizontal platform with the engine running in the "P" mode, and on some boxes - "N". A low level may be the result of unskilled automatic transmission maintenance or fluid leakage. The elevated level may have been deliberately maintained due to a strong leak. If the level cannot be distinguished, and the liquid on the dipstick is foamy and contains small air bubbles, then this may indicate both insufficient and excessive amounts of liquid. Fixing a severe leak is already an expensive automatic transmission repair, and prolonged operation with a low oil level can lead to intense transmission wear.
You can also assess the condition of the automatic transmission by appearance oils. Drop the fluid from the dipstick onto a sheet of white paper after the automatic transmission has been running for a long time. An opaque liquid, a liquid with small black particles or with a whitish emulsion tint, a burning smell already indicate serious automatic transmission malfunctions. When visually inspecting the automatic transmission, it is necessary to pay attention to oil smudges, the condition of electrical harnesses and connectors, and oil lines. If there are mechanical damage or traces of welding on the pallet, then they could cause damage to internal elements and parts located almost close to the pallet.
Diagnostics of automatic transmission in motion
It would be time to move on to checking the automatic transmission in motion, but take your time - everything has its time. First, evaluate how the automatic transmission modes are turned on. Start the engine, press the brake pedal and move the automatic transmission lever to different positions. If every time you turn on you feel a characteristic slight push, then the box is working. And strong shocks when switching on modes or a delay in switching on modes by more than 1-1.5 s may already indicate automatic transmission malfunctions. Now you can check the automatic transmission in motion.
During a test drive, you should pay attention to the quality of gear shifting in all modes. There should be no shock, vibration, extraneous noise. With moderate pressure on the gas pedal, the gearshift "up" should occur without increasing engine speed. It would not hurt to also check the forced inclusion low gear kickdown. If all the above checks did not find out the malfunctions of the automatic transmission, then it should be serviceable.
For greater certainty, you can also conduct a parking test, which will allow you to find out the condition of the gearbox and the engine as a whole. The parking test must only be carried out by an experienced mechanic! Unqualified performance of the test can lead to automatic transmission failure!
For this you need:
1. fully warm up the automatic transmission; securely block the wheels of the car with a parking brake, wheel chocks etc.;
2. start the engine and press the brake pedal with maximum effort (hold it in this position until the end of the test), turn on the "D" mode, press it all the way and hold the gas pedal (no more than 5 s!), Determine the maximum speed using the tachometer engine.
Attention! If the tachometer readings exceed 3000 rpm, the gas pedal should be released immediately!
After a 5-minute break, repeat the test in "R" mode. For a serviceable engine and automatic transmission, the maximum speed value in both tests should be the same and be in the range of 1800-2500 rpm (depending on the car model).
Majority modern cars with automatic transmission have electronic system management automatic transmission. Please note that if the control lights "0D OFF", "HOLD", "S", "CHECK TRANS", "POWER", etc., flash, the inscriptions "Getribe Program", "Gearbox Malfunction", "Check Engine" light up etc., then fault codes are stored in the memory of the control unit. You can decrypt them at the service station.
We hope that our advice will help you choose nice car with an excellent automatic transmission that will delight you with its flawless operation and comfortable ride.
The disdainful attitude of the male half of the multi-million army of motorists to the automatic transmission has sunk into oblivion: today this type of transmission is no longer put in line with insufficient driving skills. Moreover, gradually mechanical transmission becomes bad manners, and it is equipped mainly with initial configurations. But the automatic transmission has a serious drawback that weakens its main advantage, the ease of driving. This is a high repair cost. That's why it's so important when buying a used car to make sure you don't end up with such an expensive repair any time soon. Today we will tell you how to independently check the condition of the automatic transmission when buying a used car, which will help solve the above problem without involving specialists.
Conversation with the seller
It is far from always possible to count on the frankness of the owner of the car, but this must be done - often it is after a conversation with the car owner that it becomes clear that you need to look for another option.
You should be interested in three things:
- in what modes / conditions the car was operated;
- whether scheduled maintenance automatic transmission;
- Has the automatic transmission been overhauled?
You should be very suspicious of a car that has:
- there were many hosts;
- if it was used (for example, as a taxi);
- with a towbar (this means that the machine was often used to transport heavy loads, which for automatic box very bad);
- if the owner of the car is an active hunter, fisherman or a lover of long-distance travel.
Check for abrasions on the towing eyes - for automatic transmissions, towing is even more harmful than transporting goods. Note that this type of transmission is unsuitable for operation in extreme conditions: even 15-20 minutes of active slipping is enough to overheat gear oil followed by gear failure.
Try to find out if the transmission oil was changed on the car you liked. If not, then with a mileage exceeding 80,000 km, problems with the box are inevitable soon, even if you immediately change the oil.
If the answer is yes, ask how many times and at what mileage the change was made, who changed the oil, and for which one, whether the filter located in the pan was changed. Most manufacturers recommend that this operation be carried out with a mileage of no more than 60,000 km., A value of about 35,000-45,000 km is considered optimal. ATF type transmission oil is poured into the automatic transmission, but the products of far from all manufacturers are compatible with each other. The procedure itself is not as simple as replacing engine oil, and in models with on-board computer this operation requires a mandatory connection to the "brains" of the car, otherwise there will be problems.
You should also refuse to buy in the case when the automatic transmission has been repaired - even if the car owner shows documents confirming the fact that such work has been carried out in a car service, it is not known how the box will behave in the future. A repeated breakdown will leave practically no chance for a successful repair, and replacing the automatic transmission completely is a very dubious pleasure. As an exception one can mention complete replacement gearbox, and even then, if such work was carried out at a certified car service. In any case, ask what caused the replacement of the gearbox.
If you notice signs of insincerity in the owner's answers to your questions, you should definitely continue the examination.
Checking the condition of the oil
And you need to start by checking the quality of transmission oil. Formally, all automatic transmissions are divided into two types, serviced and unattended. But if we put aside formalism, then it should be understood that all automatic transmissions, without exception, need maintenance. Therefore, any arguments against non-compliance with the timing of replacement lubricating fluid such as "the box is unattended" are untenable.
Alas, many car owners are unaware of this issue, which in most cases becomes the main cause of premature.
So, what can be understood by examining a transmission oil sample taken from the box? It can be examined according to five important criteria, without the need for laboratory tests:
- check the oil level;
- liquid color;
- consistency;
- smell;
- purity (presence/absence of suspended particles).
If the type of transmission is maintenance-free, then it will be difficult for you to obtain an oil sample (due to the absence of the necessary technological hole), so you will have to limit yourself to studying the smell from filler plug. All other tests without visiting the service station will not work.
Serviced automatic transmissions have a probe that allows you to do everything.
The first of these is the analysis of the level of TA. It should be between extreme risks (usually they are denoted by the words Cool and Hot). Too much oil is just as bad as too little.
The color should be close to the original, that is, vary from red to dark red. Brown color without the presence of suspended impurities can also be considered a variant of the norm, but in this case it is not worth delaying the replacement of the lubricant. The darker the oil, the worse, and if it is also opaque, then it is better not to buy such a car.
Normally, TG has a thick consistency. If it flows off the dipstick like water, what lubricating properties can we talk about?
Gear oil usually has a characteristic odor that should remain so. If you smell burning, this indicates that the friction discs are burning. The smell of rotten fish is proof that the oil has not been changed for a long time. In both cases, the purchase must be abandoned.
Finally, if foreign suspensions are visible in the test liquid, regardless of origin, this indicates that it was replaced quite recently, that is, before sale. And this is also something to think about.
Automatic transmission check at XX
Indirect signs only indicate potential problems, but real ones can be identified by checking the operation of the automatic transmission in real conditions. And you need to start with the diagnosis on Idling, after turning off all electrical appliances that are sources of noise in the car.
Algorithm for checking the operation of an automatic transmission on a car at XX:
- depress the brake pedal;
- we run the selector lever in all modes, with a small time delay between switching (within 3-5 seconds). Gear shifting should occur clearly, without delays of more than one second. And - no additional symptoms such as creaking, jerking, kicking;
- repeat the same operation with the brake pedal depressed, but without time delays. Again, everything should happen clearly, without suspicious manifestations;
- another way to check is to switch the selector in the sequence: “Drive” - “Reverse” - “Drive” with a maximum delay between switches of one and a half seconds. In this mode, there should also be no jerks, jerks and incomprehensible sounds. Smooth shocks with a small amplitude during this check are acceptable, but if they are intermittent and short, if clicks and other sounds are heard during switching, we do not recommend buying a car with such an automatic transmission.
A serviceable automatic transmission should work quietly, without complaints.
Driving check
But the maximum information can be obtained only by testing in real conditions. Only such a check of the car's automatic transmission will give an idea of the condition of the torque converter.
Tests are carried out in all four main modes of operation of the automatic transmission: neutral, driving, reverse and in parking mode. Depress and release the brake pedal before shifting the selector lever. So, if you select the Drive mode, the car should move smoothly, without slipping and sharp jerks. When choosing mode N, the box should turn off, and without a time delay.
Signs of the normal state of an automatic transmission are soft, smooth and almost instantaneous switching in all modes. If there is a pause between pressing the selector and switching, we can talk about the inaccuracy of the device, but when the pause lasts more than a second, we can conclude that the box is very worn out.
In mode D, check for slippage: if, as a result of actively pressing the accelerator pedal, the speed of the car remains unchanged, this indicates worn clutches or another malfunction of the automatic transmission that prevents its normal operation.
Stall speed test
Another rather revealing test, carried out at idle with the accelerator pedal depressed. Its essence is to determine the maximum value of the number of revolutions in all modes except N and P. It is recommended to perform a stall speed test in cooperation with an experienced specialist who can determine everything possible problems in the operation of the automatic transmission.
Fast acceleration and deceleration
It is best to check the effectiveness of the switching of driving modes in this way. Its essence is as follows: carried out.
When the speed drops to the level of 800-850, we press the brake pedal and then just as smoothly - on the gas pedal. Before reaching a speed of about 60 km / h, the box must move from the first speed to the second, and then to the third. Subsequent acceleration to 80 km / h must be accompanied by another switch. With each such action, a decrease in the number of revolutions should occur, the moment of switching can also be monitored by sound.
When braking hard, the box should immediately shift into first gear.
If such a check of automatic transmission switching when buying a used car did not reveal any problems, you can proceed to the remaining testing modes.
Checking kickdown
The term kickdown should be understood as a sharp pressing on the gas pedal while the car is moving. In this case, there should be a transition to one or two gears in the direction of reduction. The mode is needed for more active acceleration of the car (for example, when overtaking). Upshifting will occur automatically only when power unit maximum rpm. Such a check when buying a car allows you to identify changes in the automatic transmission, indicating its wear.
Checking for oil leaks
Another type of test does not even require starting the motor. We are talking about the study of the car and the place of its parking for the presence of transmission oil stains. However, their presence does not always allow you to correctly localize the place of loss of tightness, but the very fact of the presence of leaks will eloquently indicate the presence of problems with the automatic transmission. Of course, the level of TJ can be corrected, the spots on the box and the motor can also be removed, but if there is a leak, it will manifest itself as oil stains found under the car. If the owner refuses to rearrange the car under a fictitious pretext, think about whether it is worth dealing with such a car.
Summary
If you are determined to buy a used car with only an automatic transmission, you should be very thorough in checking its performance, using all available methods. Failure to provide a car for inspection while driving is a clear sign that the car owner is hiding something. Remember that a problematic automatic transmission practically guarantees you expensive repairs in the short term, and the cost of this event can in some cases reach 25-40% of the price of the car. So it's better to look for an instance with a known-good automaton, even if .
Pay attention to the smell of oil in the box, there should not be any foreign smells, especially the smell of burning. It is also recommended for color, drop it on a piece of paper. The color of the oil should be reddish, if the oil has been changed for a long time, it may acquire a brownish tint, but in no case black. The dark color of the oil, the presence of any particles in the oil, or the presence of an extraneous odor are those signs in the presence of which it is better to immediately refuse to buy. Metal particles or even flakes in the box are absolutely unacceptable. The automatic transmission has a large number of precise elements that are easily damaged by such particles.
Some cars are not equipped with the probe described above, then it will be possible to check the level and condition of the fluid in the box only with the help of computer diagnostics.
So, if the car passed the preliminary selection, we go directly to testing the box in action, that is, in motion. Do not forget about accuracy and caution - the car is not yours yet. There are several lever positions: neutral, praking, drive and reverse, that is reverse, they are denoted respectively by the letters N, P, D, R.
Squeezing out the brake pedal, try several times to smoothly switch the box to each of these positions. Switching should occur instantly and with a characteristic push, in the neutral position of the automatic transmission lever, the box is turned off. If the reaction of the box is delayed by at least one second, this indicates the inaccuracy of the box. And any inaccuracy subsequently turns into a breakdown and costly repairs.
By ignoring the automatic transmission diagnostics, you can “get” for its repair
The next stage of verification is the check-in itself. Before leaving, the engine needs to be warmed up a little, when the speed has dropped to 800 per minute, you can go. With the brake pedal pressed, move the lever to the Drive position and gradually accelerate the car. Already when accelerating to 60 km / h, you should feel the gear change twice, first to second, and then to third gear. Here, when working, the box should also not be extraneous sounds or strong shocks, as well as delays in the response of the box to commands.
If the machine is equipped with an overdrive button, this should also be checked. This check is made at a speed of 60-70 km/h. When this mode is turned on, a working box switches to a higher gear, and when turned off, to a lower gear. When the Overdrive mode is activated, the mode will start flashing ” check engine” - the box may be faulty.
Now, knowing how to check the automatic transmission, you will be careful when. No matter how the seller assures you that the noise, for example, disappears when the car warms up, or vice versa, it appears only when it is hot, you should not fall for the trick. should not slip when switching, that is, there should not be a phenomenon when, when you press the gas pedal, the speed increases, and the switching is delayed. There should be no noise or knocking, jerks or jerks in the box, it should not jerk the car, but work smoothly and silently.
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Instruction
An automatic transmission is a very complex device, consisting of numerous parts and seals. Wear of just one element leads to incorrect operation of the entire unit. Also, the automatic transmission is sensitive to overheating. Half an hour of slipping in the deep is enough to burn the box. The oil in an automatic transmission should be changed more often than in a mechanical one, and driving on the "old" oil is more deplorable. The wrong choice of oil poured into the box can ruin it on the very first day of operation. In addition, machines do not tolerate repairs well and do not last long after it. Therefore, practical Americans and Europeans do not repair the box, but change the assembly.
It should also be remembered that the repair of an automatic transmission is very difficult and very expensive.
Before checking the automatic transmission, it is useful to find out the cars. This can save time and money. If the car was used at a rental or was restored after a serious accident, the automatic transmission will not last long. The same can be said about the already repaired box. All repair automatic transmissions have problems. And not all workshops can professionally repair automatic transmissions. The presence may indicate increased wear on the machine caused by the transport of a trailer.
Checking the automatic box.
First, you should check the oil level in the box and its condition. In this case, the engine must run on idling, the selector of the machine to stand in the "parking" position. The transmission dipstick is removed, wiped with a clean cloth and inserted back. Now pull out the dipstick again. To assess the condition of the oil, the dipstick is wiped with white paper. The paper should leave a clean and transparent mark without metal or foreign particles. New oil is red. Not new may be brownish, but not black. And it doesn't have a burnt smell.
Please note that modern automatic transmissions do not have an oil dipstick. Checking the level and condition of the oil is possible only in a specialized technical center.
Testing automatic transmission on the go.
The delay between the moments of selecting the position of the selector "D" or "R" and before turning on these positions of the selector is a sign of a defect. First, you should warm up the car and the box in the "P" (parking) position until the speed drops to 600-800. Holding the car in place with the brake pedal, the selector switches to "D" (driving). The machine should immediately select this mode and start trying to drag the machine forward. Everything should happen smoothly, without pushes and knocks. Further, when switching to "N" (neutral), the box should turn off. Now, when you turn on "R" (reverse), the automatic transmission should also turn on instantly, without clicks and knocks. The car should try to crawl back.
While holding the brake pedal, you should check the box, switching from "D" to "R" and vice versa. There should be no jolts or knocks. Delay more than 1 sec. when you turn on any mode, it indicates wear or damage to the box.
To further check the box on the go, it is necessary to develop a speed of up to 50-60 km / h. Gears should shift at least two times, smoothly, without shocks and delays. The fact of a gear shift is determined by a slight change in the noise of the motor and a drop in its speed. With excessive wear of the automatic transmission, a push, delay or shock is felt at the moment of shifting.
At a speed of 40-50 km / h, you should drown the accelerator pedal to the stop. A properly working machine will shift to a lower gear, engine speed will increase.
If there is an overdrive mode (button to the left of the automatic transmission selector on Japanese and American cars), it is also checked. To do this, at a speed of 60-70 km / h, the ON mode is turned on by pressing the overdrive button. The transmission should shift up one. When overdrive is turned off, the gear shifts one down.
The problem of slipping gears is as follows: when you press the gas pedal, the speed increases, but the speed does not increase.
Checking the automatic transmission for defects and malfunctions when buying a used car about a very important part of the inspection of the purchased car, because its cost is not a small fraction of the cost of the car as a whole.
How to check automatic transmission
The automatic transmission is a fairly reliable thing, but compared to the rest of the car, it is practically its most vulnerable part. A few jams in the snow or mud and the gearbox simply “burns out”.
It is possible to repair an automatic transmission, but it has a large number of precise parts. The ingress of dust particles, specks or an error during repairs - all this can cause another breakdown. To avoid such situations, when choosing used cars, special attention should be paid to the condition of the automatic transmission.
If you can not do this work yourself - contact for.
Checking under the hood
Check the oil level in the gearbox and its condition. To do this, put the automatic transmission lever in the "Park" position. Start the car, remove the dipstick from the transmission of the gearbox and wipe the oil from the dipstick. Then insert and remove the dipstick again. Now touch the oil dipstick to white paper (you can nail). There should not be any foreign flakes or metal particles on the oil stain. The color of the new oil is red. If the lubricant is already old, then it becomes brown, and in some cases almost black. Evaluate the smell of the oil - it should not have a burning smell
If there is no oil dipstick, then you need to go to a specialized technical center, where specialists will perform all the necessary work.
Standing check
Check the work automatic boxes standing on a horizontal platform. Put your foot on the brake and move the handle to the “D” position, after that the car starts to pull forward, as it were, when the gear is engaged, there should not be any jerks or jerks. R ”- almost instantly turns on, and the car starts to pull back slightly. There should also be no unnecessary knocks and jerks. Release your foot from the brake without adding speed, the car should roll slowly in accordance with the selected “D” or “R” mode. Please note that if at least a second delay occurs when the gear is engaged, then you can speak about the wear of the box and the need for its repair.
Stall test
The check is carried out only in a warm state while standing on a horizontal platform. Press the brake pedal and move the handle to the “D” position, without releasing the brake pedal, press the gas pedal smoothly to the stop, while the car should immediately pull in front, and when you further press the gas pedal to the stop, the engine speed should not exceed 2500 rpm. , if the speed continues to grow, then the torque converter has a slip, if the engine speed does not reach up to 1500 rpm, this also indicates that the automatic transmission is not working, and the internal combustion engine may not produce the required power. This method of checking automatic transmission is called Stall Test and it is carried out exclusively on a warm car, while pressing the gas pedal with the brake pedal depressed should not exceed 5 seconds, and a second test should be carried out no earlier than after 10 minutes.
Check on the go
Take a test drive with the vehicle being inspected. Accelerate to a speed of 50-60 kilometers per hour, the gear shift should be carried out at least twice. At the same time, there should not be any delays, shocks or jerks. Pay special attention to the moment of gear shifting. Shocks, delays or shocks are a sign of a worn automatic transmission that needs urgent repair. At a speed of 60 km / h, press the accelerator pedal all the way. If the machine is working, then the automatic transmission will switch to low speed and the tachometer speed will increase.
Another manifestation of a worn gearbox is when, when you press the gas pedal, the speed increases, but the gear does not change, the box “slips”.
Drive the car in various modes, be it hard acceleration or smooth acceleration, the car should behave naturally without showing any incorrect operation of the gearbox.
For a more complete understanding of the operation of the automatic transmission of your chosen model, you need to test several cars.