If everything is clear with motor lubricant, the question of when to change the oil in the gearbox and whether it should be done at all is still an open question for many motorists. It seems that everything is tight there, no pollution gets inside, so there seems to be no need for replacement. Moreover, some manufacturers claim that the oil they fill will be enough for the entire life of the vehicle.
So whether to change the oil in the gearbox or drive and not worry about it?
Why replace?
The composition of both motor and transmission oils includes a base and additives. Based on this, their properties are revealed, and additives also improve the work by performing various functions.
In addition to lubricating oils, transmission oils perform another important task: they remove heat from the gears that are engaged.
On average, the temperature in the checkpoint is kept at one hundred and fifty degrees, and in the gearing itself it reaches three hundred. At such high loads, the lubricant naturally begins to foam and lose its beneficial properties. In automatic transmissions, it also plays the role of a working fluid, transmitting torque from the engine to the gears.
If it comes to foamed grease, the machine simply will not be able to drive. In this case, even special radiators designed to cool the liquid will not help. However, the situation is saved by special additives that are part of the oil.
When to change gearbox oil
So, a replacement may be required precisely because additives lose their functionality over time. They cease to reliably protect friction parts, which is why the latter undergo rapid wear. Foamed oil can cause seizure of the final drive.
As a result, the gears begin to buzz. And after fifty kilometers, the process of their destruction will begin. It will all end with the box jamming and it will be impossible to drive. This is characteristic of front-wheel drive and all-wheel drive. For rear-wheel drive vehicles with a manual gearbox, the oil does not experience such strong temperature loads. Therefore, it can be used up to twenty thousand kilometers longer than with automatic transmission. Usually, when the time comes when it is necessary to change the oil in the gearbox, the period of changing the oil in the gearbox also applies. The procedure is carried out in order to remove dirt and chips released during the operation of the gears that come out with the grease.
In order for the mechanism to wear out less and last longer, manufacturers usually designate the period after which the oil in the gearbox is changed, from fifty to sixty thousand mileage, and even under extreme operating conditions, from thirty to forty thousand.
However, there are a number of models in which transmission grease is poured for the entire duration of operation. In such cases, not even a drain plug or dipstick is provided to check the level.
CVT
Separately, it should be said about the automatic transmission, namely about the variator varieties. To understand when to change the oil in an automatic transmission of this type, you need to study their principle of operation. The fact is that they are not arranged like a conventional transmission, although they belong to the automatic class. The mode of their functioning is more rigid, therefore, lubrication for such boxes requires special. It is recommended to change it once every fifty thousand kilometers, and if usually the ride is intense, then once every thirty thousand. The frequency of such a replacement must be strictly followed, since under such conditions the additives lose their properties much faster.
Regarding whether to rinse the unit when replacing or not, as well as in the case with engine oil, experts have no consensus. I just want to say that if this is done, then it is best to use the same oil, which will be filled in the future. Such washing will be the key to stable and long-term operation of the transmission in the future.
Check
Manual transmission oil levels are usually checked after a night of machine downtime. The longer she stood with the engine turned off, the more accurate the results will be in order to understand when to change the oil in the gearbox.
To do this, wipe the crankcase, where the speedometer drive is located. The bolt is turned out, the fasteners are removed, and then the assembly is removed. The bolt itself, of course, is better to pour a “wedeshka” and be careful not to rip off the head.
Check is carried out by a driving gear of a speedometer. Slight overshooting is permissible. But his lack should not be in any case.
Replacement
If the recommended mileage has been passed, and the time has come when to change the oil in an automatic transmission or mechanical, as well as if during the check you came to the conclusion that this must be done urgently, the process starts on a pre-warmed motor.
Draining is done by unscrewing the plug located at the base of the crankcase. It is pre-wiped and the container is substituted. After leakage, the thread is wiped, a new washer is put on, and the cork is attached in place.
It should be noted that automatic transmission does not completely drain the oil. However, it will be enough to remove the abrasive from the inside.
What kind of oil to fill
It is important not only to know how often to change the oil in the gearbox and follow this, but also to use exactly the grease that is suitable for your car. You must purchase the fluid that is prescribed by the car manufacturer. However, if the instruction manual is not preserved, then follow the general recommendations.
Oils, both motor and transmission, are mineral, semi-synthetic and synthetic.
Minerals are usually used only in individual trucks and domestic rear-wheel drive cars.
Semi-synthetic is also shown to our cars and those foreign cars that are operated at low speeds. It is inexpensive and has better characteristics compared to mineral water.
Synthetic oils are the most expensive, but they are also equipped with the best package of all kinds of additives, whose properties last much longer. Therefore, the period through which to change the oil in the gearbox, when using synthetics, will increase.
For the excellent performance of the gearbox, it is better, of course, not to spare money for oil and use synthetics. ATF ( automatic transmission oil ) can often be used for mechanics: it has better characteristics compared to those recommended for manual transmission.