This preventive service is recommended by several automakers and serves to maintain the proper functioning of the gearbox
When we talk about changing oil in the car, the first thing that comes to mind is the engine lubricant. But the automatic transmission also has a similar fluid, called ATF, which requires periodic changes, otherwise the owner may receive a hefty bill later.
The manual transmission also has its oil, but here we will focus on the automatics. This type of box already represents more than 50% of new car sales and its demand has also grown in the used market.
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Checking the automatic transmission oil or asking the owner if the changes have been made is a habit that should be part of the routine of anyone looking for a used car.
The deadline for changing the gearbox oil is determined by the manufacturer in the vehicle’s manual. If you don’t have this document, you can find it on the manufacturer’s website.
In conventional automatic transmissions, the suggestion is usually to change every 60 km. In older models, the deadlines were shorter, in the range of 40 thousand km. There are also vehicles that promise greater oil durability, the Ford Transit’s 10-speed gearbox requires a change after 250 km.
In CVT transmissions, it is also necessary to change the oil, called CVTF. The range is closer, Honda indicates doing it every 40 thousand km in its current cars, for example.
There are brands that only recommend changing in severe use. It is good to remember that short trips, heavy traffic, traffic jams and mostly urban use is considered severe.
Mechanic Ludovico Ballesteros, owner of Pitucha Centro Automotivo, explains that this fluid works with pressure and temperature inside the gearbox. With use, it loses its properties and accumulates the internal wear of the automatic gearbox.
Happening this starts to jerk in the changes, slippage and increases the wear and tear of the components, which can end in a serious, serious problem in the transmission.
The automatic transmission has oil as an essential element for its operation. It works in a pressurized manner and moves through the component to change ratios.
And the box only works with pressurized fluid. Therefore, when it loses its properties, the operation becomes irregular.
Changing the gearbox oil is not as simple a service as that of the engine lubricant. It needs to be done in a workshop that has the necessary equipment.
Let’s use as an example the Honda Fit of the reporter who speaks to you, which is one of the most sought-after used automatic cars on the market. The manufacturer recommends changing it every 60 km.
The service with the total change of the fluid came out for about R$ 1,780, including labor. A replacement gearbox costs around R$ 10 thousand, but it is a used part. If you add the workforce, it can exceed R$ 15 thousand.
There are two ways to change the automatic transmission oil. The simplest is partial, where the plug is opened and the liquid is removed by gravity. That way not all the fluid comes out and the volume exchanged is smaller, about 2/3 of it.
The total change requires specialized equipment. Motul explains that the process is like dialysis, where the machine is connected to the gearbox and it is put to work.
During the process, the new oil also cleans the box from the inside. Therefore, two liters more is also used. But at the end of the service, the car has all new fluid and avoids contamination.
The car has symptoms if the gearbox oil is not changed. Ludovico says that it can have jerks in gear changes, delays, especially in changes for drive or reverse and can even emit a burning smell.
There is also a warning light on the dashboard. Insisting on running like this can cause internal damage to the box, with very expensive repairs.
Like the engine oil, the automatic transmission also has a dipstick for checking the level. It is more hidden and the procedure for verification is different.
Before pulling it to see the level, you need to run the car’s engine until it reaches operating temperature. Then stop the engine, remove the dipstick, clean it, put it back on the gearbox and remove it to see the level.
The gearbox oil should be checked while it is already warmed up, so be careful when cleaning the dipstick before checking. If the level is below the recommended level, look for a workshop.
Currently the gear dipstick is missing, it is easier to find it in cars over 10 years old, especially in the Japanese. Without it, you need to go to the mechanic to evaluate the fluid.
A controversy that came with the popularization of automatic transmissions in Brazil is that of the gearboxes that do not require an oil change. According to the manufacturers, they come sealed from suppliers and the fluid lasts for the entire life of the vehicle.
The big problem with this is the time they consider as “vehicle life”. In Europe, this period is considered to be 180 thousand km. But that doesn’t mean the car will stop running after that mileage, if the car is well cared for it can run much longer than that.
Cars that do not recommend changing the gearbox oil do not bring the dipstick for checking. The gearbox is already sealed at the factory to prevent air from entering the interior, so as not to contaminate the fluid.
They also use a different ATF oil, already thought of greater longevity. Roberta Teixeira, director of Lubricants at the Brazilian Association of Automotive Engineering (AEA) explains that the longer durability is related to the evolution of base oils and the additives added to them:
Long-life fluids have greater resistance to oxidation, less deposit formation and greater viscosity stability, even when subjected to high temperatures.
The evolution of automatic transmissions also helps with durability, so much so that cars that require changes have a greater periodicity than older models. “Modern gearboxes have more efficient electronic control systems, better temperature management and filtration systems that help reduce fluid contamination throughout use”, points out Roberta Teixeira.
The lower stress of the gearbox contributes to the gearbox oil lasting longer. But the specialist comments that severe use can impact the long-life fluid:
Although it is a real condition due to technological advancement, the driving conditions in large cities have demanded too much of these fluids, causing the km of change to reduce to periods of 60 thousand km to 100 thousand km.
As usual, severe use is always a factor to consider in car maintenance. Not even the oil made to last the entire life of the vehicle is safe.
