Issues addressed in the material:
- How oil works in automatic transmission
- How often do I need to change the oil in the automatic transmission
- What kind of oil do I need to fill in automatic transmission
- What is a full and partial oil change in an automatic transmission
- How to replace oil in automatic transmission yourself
Automatic transmission, or automatic gearbox, is a very significant and expensive mechanism (after the engine) in the latest machines. In order for the machine to work stably and correctly, you should change the ATF in the gearbox in time. If you do not carry out the replacement on time, then this mechanism may become unusable, and the repair will be quite expensive. From the article you will learn about why it is necessary to replace the transmission fluid and how to replace the oil in the automatic transmission.
The purpose of the oil in the automatic gearbox
First, let’s see how the “automatic” box in a car works. An automatic transmission connects the motor to the wheels, converting the torque of the power device into the energy that is needed for movement. In the “automatic”, the engine crankshaft is connected to a torque converter (GDT), in which the output shaft does work with transmission devices. The latter drive the wheels of the vehicle.
Reasons why automatic transmission requires ATF (Automatic Transmission Fluid):
- The correct operation of the mechanism is normalized . The oil helps to evenly transmit torque to the transmission. As a result, the car moves smoothly, smoothly. Transmission fluid is like a clutch pedal in a gearbox. ATF also helps move HDT mechanisms.
- It is an actuator . The electronic control unit sends an ATF command, which puts pressure on the necessary channels in the device. Thus, gear shifting is carried out.
- Cooling is in progress . Metal devices heat up during operation. The fluid normalizes the operation of the mechanisms, removing heat into the crankcase.
- It plays the role of lubricant . Automatic transmission mechanisms are made of metal. They are constantly moving, interacting with each other. Without lubrication in this process can not do. It extends the working time of parts, reduces friction, wear.
- Displays processed products . During the operation of the devices, various debris appears: chips, dust, etc. Using additives that are added to the transmission fluid, it cleans the mechanisms of litter, contributing to their better work.
Not so long ago, some manufacturers of popular brands came up with a chip: in their cars there is no need to change the oil. Such information was indicated in the service documents for servicing the machine. One of these “smarties” was the German triumvirate: Audi, BMW, Mercedes.
Drivers were pleased with this turn, because no one wants to pay extra. However, the experience of subsequent years showed what to do: it is better to replace the oil in the automatic transmission completely than wait until the mechanism wears out and becomes unusable.
Manufacturers soon realized this, because the number of cases when the automatic transmission failed after a significant mileage increased.
Today, technical fluids are produced an order of magnitude higher quality than several years ago. Modern oils can work at critical temperatures and in various extreme situations. However, this is not a reason to save on the purchase of oil.
The movement has become more intense, significantly increased loads on parts, mechanisms. The gearbox is no exception. Transmission fluid loses its properties over time, becoming unsuitable for lubrication and cooling of automatic transmission devices.
Timely replacement of ATF will protect the gearbox parts from various debris formed as a result of friction of metal mechanisms, pads, wear products. If you postpone the oil change for an indefinite time, then liquid based on various debris will adversely affect the entire automatic transmission as a whole. As a result, you get an unusable device.
When you need to change the oil in the automatic transmission
Each manufacturer prescribes the rules, which indicate the date of the oil change. It is different for each brand of car. Although everyone writes an approximate interval in the region from 50 to 120 thousand kilometers. For example, BMW AG, which assured that there is no need to change its ATF, advises to fill in a new transmission fluid after overcoming a threshold of 50 thousand km, or after three years of operation of the machine.
If the car is used in normal mode, then you can change the oil after two years of operation or after 60 thousand kilometers.
ATF can be replaced earlier, without waiting for the recommended date, if the fluid has exhausted its life.
In areas where high humidity prevails, sudden changes in temperature, oil should be replaced more often: once a year or after 30 thousand kilometers. If the car is experiencing increased loads every day, then in this case you need to change the transmission fluid before the time specified by the manufacturer.
In this case, it is necessary to take into account the influence on the car of such factors as:
- weather;
- load;
- driving style.
Let’s talk a bit about driving style. For drivers who prefer to drive too energetically, the transmission fluid resource is much shorter.
This happens:
- with a constant change in speed modes, accompanied by sharp braking;
- at the beginning of movement from a traffic light with the gas pedal depressed all the way – kick-down technique;
- when entering a turn at high speed.
Such methods of transportation very heavily load all the mechanisms of the car. In this case, intense heating of the parts occurs. Accordingly, ATF loses its properties very quickly and requires more frequent replacement.
It is easy to test the structure of ATF yourself. Pull out the dipstick and inspect it. Fluids of proper quality will be a light shade. If it is dark enough or it smells bad, then you have a direct road to a car service.
In some cases, if the automatic transmission does not work very well, this may indicate a low oil level or an exhausted ATF. Here are the most common situations:
- Oil pressure in the line is not very high.
- During gear shifting, the car begins to slip.
- With a long rise at extreme speed, the gearbox begins to slip and a shift to a lower gear occurs.
- The car does not go at all.
- There is no way to switch from P or N to another speed.
- During the inclusion of speed there is a push, speed switching, but the car stands still.
What kind of oil do I need to fill in automatic transmission
Before you change the oil in the automatic transmission yourself, you should find out its brand.
The fluid that is poured into the manual transmission contains components that are not suitable for use in automatic transmission. Oils have different viscosity properties. If you fill in the wrong ATF, then the system may fail. Vehicle manufacturers have agreed to use red liquid for the automatic gearbox.
The question is how to determine what kind of oil was poured into the automatic transmission?
At first glance, there is nothing complicated. However, this only seems so. It happens that the document where the ATF brand is registered is lost or is somewhere lying around among other papers, or it is impossible to understand what color the oil on the dipstick is.
In such situations, we recommend the following:
- sometimes the manufacturer places the data under the hood on the information plate (on the nameplate);
- Ask for information from a dealer or authorized representative;
- find out the necessary information using the Internet.
Automatic oil change methods
Essentially, the oil change process is pouring a certain amount of ATF through the hole in the sump and adding a new transmission fluid. With the improvement of the automatic transmission structure and the advent of devices without a probe, replacing ATF has become a little more difficult. However, the principle of the procedure has not fundamentally changed.
There are two ways to replace ATF in automatic transmission:
- Change ATF completely in gearbox.
- Partially change the ATF in the gearbox.
Suppose that in an automatic transmission is about 10 liters of transmission fluid. During a normal change, only part of the liquid, approximately 5 liters, can be drained. The remainder will continue to be in the channels and “bagel” of the city traffic control. A small amount of dirt will flow out with the old ATF. However, a significant portion of the wear products will remain in the gearbox. Such a process is a partial replacement for ATF and is used most often.
Alas, vehicle owners primarily resort to partial ATF replacement in automatic transmission.
There are several reasons for this:
- Cost reduction. It is not a matter of the cost of the replacement itself, although it is quite cheap. All “salt” is in additional expenses for ATF, which is necessary in order to completely flush the entire automatic transmission system from the waste product.
- Walking Availability. In any service where a specialist can replace the oil in automatic transmission partially or completely. Although special equipment is required for a complete oil change.
Partial replacement of ATF has also disadvantages:
- About half of the waste products remain inside the gearbox.
- Almost 50% of transmission fluid that has lost its quality remains inside the system.
Full ATF replacement in automatic transmission
Quite rarely, drivers want to replace the entire fluid. However, the effectiveness of this procedure cannot be compared with the partial replacement of ATF. It is possible to completely replace the oil in the automatic transmission with the help of special equipment, or independently. Moreover, special equipment allows the use of certain mixtures for washing automatic transmissions.
The washing stage of the gearbox is necessary, since contamination is removed and good oil circulation is restored, the automatic transmission as a whole also improves, the elasticity of the rubber and plastic gaskets in the gearbox increases, which has a beneficial effect on the automatic transmission. Remember that flushing should be carried out when it is possible to completely remove it from the gearbox when replacing the ATF.
Pros of a complete oil change in the gearbox:
- Removal of various layers, pollution resulting from the automatic transmission.
- Increase gearbox life.
According to statistics, the money spent on a complete oil change in the gearbox will pay off due to the extended service life of the box.
Despite the additional expenses, a full-fledged oil change is most popular in Siberia and the Far East. This is explained by the fact that in these areas difficult conditions for the use of cars. But car owners in the central regions of our country do not know much about this method.
Drivers who do not want to spend extra money can replace ATF on their own. The process will not cause any problems if you follow a certain technology when working.
It is necessary to remember an important point: the holes for draining and filling the oil in different brands of machines are placed unequally. Beginners in this business need to use the help of the Internet. In the search line, write a request on how to replace the transmission fluid in the automatic gearbox. You should also indicate the model of your car. In a couple of seconds you will get a great list of tips.
Partial oil change in automatic transmission
ATF replacement is possible in two ways: in whole or in part. When using the first method, fresh oil is added to the existing one, thereby making the performance better.
Consider how to partially replace the oil in the automatic transmission:
- unscrew the crankcase cover;
- drain used ATF;
- through the neck add a volume of oil equal to what was drained.
This method will help replace about 35% of the total mass of ATF and at the same time save your money. Car service experts recommend carrying out such procedures repeatedly if the mileage of a car has crossed the line of 400 km.
However, the best option, according to car service workers, is to completely replace ATF, which will ensure excellent gearbox operation.
Step-by-step instructions for a complete oil change in the automatic transmission
Components required for work:
- suitable container for old oil, new ATF, small funnel;
- sealing material, automatic transmission pallet gasket;
- gasket for drain cover;
- basin to rinse parts, brush, acetone, gasoline;
- a new automatic transmission filter if you decide to replace it;
- special keys to remove the bolts (for each car its own size).
You will also need a partner who will drive the car at the end of the fluid filling. Before the start of the process, it is recommended that you drive about 10 km by car to warm up the ATF.
So, a step-by-step guide on how to replace the automatic transmission oil yourself:
- Drain ATF.“Put the car in the pit, check the handbrake, move the selector to neutral. Next, unscrew the drain plug and let the ATF drain into a suitable container. When all the oily liquid has drained, unscrew the bolts that support the sump. Then gently pull it off the sealed layer. Attention: there will be a transmission fluid in the pan that can be accidentally poured onto itself. If everything went well, then pour the ATF from the pan into the prepared container. It’s the turn of the filter. We need to remove it and collect the leaked liquid in the container. “
- Handle the pan.“Use gasoline and a brush to rinse the tray and magnets. Remove old seal, if equipped. Dry all elements with a rag that does not leave a lint. If you find different objects in the pan, metal shavings, it means that you need to inspect the automatic transmission.
If you plan to replace the filter, then now is the time to do it. You will not change, then you need to rinse the old filter with gasoline. Although it’s impossible to completely clean it. ”
- Install the pan.“The pan and the place where it will be installed should be degreased with acetone. Install the pan gasket. Next, apply sealing agent to the pallet and to the bottom of the machine where there is docking with the pallet. Install everything back and tighten the bolts.
It is important to degrease the area on the drain cover side. If this is not done, then soon the ATF will begin to dig up. We recommend temporarily closing the hole with any rag. Then remove it, immediately securing the pallet. “
- Add oil.“The amount of oil leaked from the automatic transmission should be measured. With the help of a feeler gauge and a small funnel, pour in a new ATF, which is equal in number to merge.
- “Squeeze” the oil and add.“You should find the automatic transmission oil cooling hoses: there are two of them, and they are located at the bottom of the radiator. Carefully disconnect the rubber tube located on the left in the direction of travel. Next, gently lower the hose into a container, for example, in a five-liter plastic bottle. Let your assistant start the engine in neutral without removing the handbrake. Old oil will be poured into the tank, which the automatic transmission pump will squeeze out using the new ATF. A complete replacement of the fluid has been completed.
ATF needs to be drained until you see that a lighter fluid began to flow out of the hose. Then turn off the engine, replace the cooling hose. Next, you need to measure the volume of the leaked liquid and add the same amount of ATF using a feeler. “
- Check transmission fluid level.“It is necessary to check the amount of oil according to the“ hot ”and“ cold ”marks. With a small amount of ATF – you need to top up. However, be careful, it’s better to add a little and check the level than to merge the excess, which is much more problematic. ”
