Transmission fluid change - step by step guide
How often should I change transmission fluid?
The procedure for replacing the fluid in the automatic transmission is one of the most mysterious and mystical among all the service operations that are only carried out with the car. At the same time, everything is clear with the oil in the engine – if you live in a megalopolis and want the unit to work for a long time, reduce the replacement interval to about 7-8 thousand kilometers. Everything is also clear with consumables in the brake system because you can judge about their wear visually, acoustically or with vibration. The same is with the suspension or, let us say, with the high – voltage part. But the fluid change in the automatic transmission continues to worry minds, and this is not surprising.
First of all, we must answer this question. The fact is that the characteristics of any fluid for automatic transmission begin to change naturally over time. First, this happens as the oil ages.
Secondly, it is influenced by working in difficult conditions, such as overheating or a «sporty» driving style. Do not forget about the particles from the pads of the torque converter locks, frictions, and other internal parts of the unit. The color and smell of the fluid change. Probably, you have seen how the service personnel checks the liquid on the transmission probe for color and smell — the composition should not be black and exude a burnt aroma.
The ATF not only performs the function of lubrication, and serves to remove heat from the parts, but also serves as a working body for the torque converter and hydraulic control system. At the same time, in an automatic transmission, the liquid does not decrease at least due to fumes, as, for example, in the engine.
But there is a large number of friction pairs where the wear occurs with the coloring of the particles. In order to prevent friction and aluminum dust, as well as metal shavings, from floating along the internal channels of the unit, the automatic transmission has a filter and special magnets to attract them.
Can Changing your Transmission Fluid Cause Damage?
Over time, the filter becomes clogged, and its throughput decreases. As a result, the load on the pump increases, and the oil heats up more. One day the paper filter element will simply break, and it will no longer be an obstacle in the way of contaminated oil, which affects the internal components, for example:
- solenoid valves,
- pressure regulator,
- valves of the hydraulic unit.
If the filter is metal, the car may not go anywhere. By the way, some experts advise you to change the grid, while others believe that the metal element should be just washed.
Users were often confused by the information that the fluid was filled for the entire life of the automatic transmission. In particular, a similar step was taken by some German car manufacturers, such as Mercedes-Benz, which produces its own transmissions. But then the information was corrected, requiring users to change the liquid after a certain mileage or after a specified number of years.
Experts say that replacement is necessary, especially if the car is operated in a city with frequent traffic jams, in climatic conditions with hot summers and cold winters, if the driver likes a dynamic driving style when you have to drive off-road or drag a trailer.
There are two answers to this question, the first is the answer of manufacturers of some car brands – the fluid in the automatic transmission is filled for the entire life of the automatic transmission or car, and it is not necessary to change it during operation. The second answer, from automatic transmission manufacturers, is that the oil in the automatic transmission should be changed during intensive operation of the car every 40,000 kilometers of mileage, with gentle operation after 60,000 kilometers of mileage.
Transmission fluid life
Let’s start with what the entire life of the car means. European manufacturers mean 120 000 — 150 000 kilometers of car mileage for 3-5 years of operation. Indeed, the working properties of the oil poured at the factory will be enough for the operation of the car during this period (unlike engine oil, the transmission fluid does not get combustion products formed during engine operation, and it is not spent on carbon monoxide).
In this regard, it is also interesting to refer to the recommendations of the Aisin company, which produces transmissions – according to its instructions, you should perform the procedure every 20 thousand kilometers or every two years. The corresponding image is attached if someone doesn’t believe it.
So the oil needs to be changed. It is very important to perform the procedure before the unit begins to show warning signs such as jerks or delays when changing gears. There is a high probability that the new oil will not help here, and the automatic transmission will have to be repaired.
However, there is a nuance. There are cases when the replacement of the worn-out oil helped the car to serve for a long time. The fact is that there is a friction crumb in the dirty oil and the solenoids continue to hold the pressure with it, and contact is provided in the clutches. It doesn’t happen with the new fluid, with detergents and other additives, and the resulting sludge is washed into the channels of the hydro block with obvious consequences.
The replacement method may differ depending on the condition of the unit. If you are still trying to fill a fresh ATF in a transmission that shows signs of malfunction, even if not critical, it is advisable not to carry out a full replacement, but to limit yourself to a partial fluid change.
How to change transmission fluid (Video)
In this case, the wear products are diluted with new material, and the procedure is repeated after a certain interval. Another case is if the automatic transmission is completely serviceable – then you can completely replace the fluid.