Changing the oil in the gearbox
Changing the oil in the gearbox is performed to maximize the service life of this node, which is rightly considered one of the most important mechanisms of the car. The functions of oil in automatic transmission and transmission gearboxes are somewhat different. In the first case, the lubricant plays the role of the working body, replacing the clutch pedal and controlling the work of the box itself, in the second case, the transmission fluid is responsible:
- For the lubrication of the parts that come into contact. The gears of the mechanism are constantly meshing with each other, so you need a product that reduces their friction. Lubricant slows the wear of elements and removes metal chips from the working area, which can act as an abrasive;
- protection of washed surfaces against corrosion and oxidation processes;
- cooling of the assembly. When the machine is in motion, the temperature in the clutch areas of the gears reaches 250 ° C. At the same time, the oil does not heat up above 150 ° C, absorbing the excess heat.
How often should the oil in the gearbox be changed?
Frequency of oil replacement in manual transmission should be sought in the technical documentation to the car. If such a parameter is indicated in the user instructions, you only have to follow the manufacturer’s instructions. The problem is that some automakers do not stipulate the procedure of oil replacement in manual transmission. In this case experts recommend to be guided by the 100 thousand km of run or 5-6 years of exploitation, after which it is necessary to replace the lubricant in the gearbox. It is important to understand that these figures are averaged and rather relative: the date of replacement largely depends on the car brand, vehicle operating conditions, driving style and age of the car. If we take Renault Clio II of 2006 production year as an example, it is better to change oil in gearbox of this car every 60 thousand km of run or once in 4-5 years with careful driving.
What signs tell about the necessity to change the oil in a gearbox
In some cases, it is better to replace the transmission fluid without waiting for the terms prescribed by the manufacturer or recommended by the service. This may be necessary if:
- during movement of the vehicle an extraneous noise and increased vibration is heard from the box;
- in a cold season gears are engaged with difficulty before gearbox is warmed up;
- gear shifting is accompanied by jerks, shocks and knocks, which were not there before.
Procedure of work
It is necessary to drain the warmed up transmission oil, so before starting the procedure it is better to drive 5-10 km and only then place the car on the observation pit, a trestle or an elevator. To perform the work you will need a set of keys, a screwdriver, pliers, a funnel with a hose or a technical syringe, as well as any container for used oil drainage. The oil is changed in the following sequence:
- make sure the machine is horizontal;
- unscrew the drain plug, with a container for the waste material. It is better to replace the sealing ring;
- Waiting until all the liquid is drained out, the plug is put back in place;
- unscrew the filler cap and use a syringe or funnel to fill the box with new oil. The normal level is the lower edge of the filler neck, i.e. you must stop filling the gearbox when the excess lubricant begins to pour out from under the hose or syringe.
Offer of Obninskorgsintez JSC
In the catalog of JSC Obninskorgsintez there are Sintec Trans gearbox oils in different modifications, including:
The product is made on a highly purified mineral basis with a carefully selected package of imported additives. Transmission fluid is well suited for units operating in the most adverse conditions, including low temperatures and constant overloading.
It is intended for use in commercial vehicles and trucks, buses, as well as road maintenance equipment and other machinery. The fluid not only reduces wear of parts, but also lowers noise level of transmission operation. The material is not subject to foaming and enables easy gear shifting in winter.
How often should I change the oil in the gearbox?
The list of works on the maintenance of any car includes changing the engine oil. But we should not forget that there is also oil in the gearbox. But how to determine whether it’s time to change it? Does it burn out during work and should it be added, like in the engine? And is there a maintenance schedule for the car transmission?
Why do you need oil in a gearbox?
All engine and transmission oils consist of a base oil and a set of additives.
At these temperatures the oil begins to foam and lose its lubricating properties.
The properties of oils are determined by the quality of their base chemical composition, and the additives added to oils serve to adjust and improve their performance.
Besides lubrication, gear oils have another important function, that of heat removal from meshing gears. The average temperature of the oil in the gearbox of a moving automobile is about 150 degrees Celsius, and in the contact area of meshing gears it is about 300 degrees. At these temperatures the oil starts to foam and lose its lubricating properties. In automatic transmissions the oil is also the working body which transmits the torque from the engine to the gears and the foaming oil simply does not let the car move. Even special radiators, installed for oil cooling, do not help. To prevent this from happening, a special additive package is added to the oil.
When and why change the oil?
The oil has to be changed, first of all, because the additive package has lost its effectiveness. Over time, during operation, the additives lose their properties and no longer provide reliable protection for the working surfaces. The oil begins to foam and scuffing of the main gear can occur. The consequence is a tedious humming of the transmission differential gears, which will intensify, and after 300-500 kilometers of run the gear teeth will start to deteriorate. Eventually the gearbox will jam. This happens on all-wheel drive and front-wheel drive vehicles. The gearbox is not exposed to such thermal stresses at the cars with rear drive and manual gearbox, and the oil can serve for 10-20 thousand longer without losing its lubricating properties. But its replacement is usually timed to coincide with the oil change in the gearbox. It is done to remove particles of dirt and swarf which are generated by the gears and come out of the gearbox crankcase together with the drained oil.
To avoid this, the manufacturers recommend changing the oil in the gearbox once in 50-60 thousand km of run, and if you drive with intensive “acceleration-braking”, the period of replacement is reduced to 30-40 thousand km of run. These recommendations do not depend on the total mileage of the vehicle.
In some models of cars, the transmission oil is filled for life. In this case, there is no drain plug in the transmission crankcase.
Speaking about the maintenance of automatic transmissions, it is impossible not to mention the variator boxes, which have become widespread in the modern automobile industry. Although they are considered to be automatic, but they are designed quite differently and work in a very harsh temperature regime. Conventional automatic transmission oil is not suitable for them – there is a special fluid. It is recommended to change liquid in variator every 40-50 thousand km, and with intensive driving the change is reduced to 30 thousand. The frequency of changing the CVT fluid must be strictly observed as the additive package breaks down much quicker than in conventional transmission oil due to the constant high load on the CVT belt and the harsh temperature conditions.
Gearbox crankcases are not flushed when changing gearbox oil – this is not necessary. When repairing by disassembling the box, all dirt is manually removed from there and the magnet is cleaned, which collects on itself the shavings resulting from the gears. It is not worth saving, and after assembly of the unit, the engineers of dealer centers recommend new oil, even if the planned replacement was quite recently, since the use of fresh oil is the pledge of reliable and long-lasting gearbox operation.
Modern synthetic gear oils are all seasonal and can operate without losing their lubricating properties in the temperature range from -50 to + 50 degrees Celsius. They don’t get thick, they don’t lose their viscosity properties in cold and heat, that is why cars can be driven with these oils practically everywhere.
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March 27, 2015 Tags: transmission , transmission , acp , transmission oil , automatic , manual , variator , differential