To keep your car running smoothly, it needs constant care and maintenance. Of all the technical procedures, changing the oil in the rear gearbox is not the most frequent, but extremely important. A gearbox is a special gear mechanism that connects two axle shafts, which is responsible for converting engine power and transmitting it to the wheels. It allows the wheels to rotate at different speeds. Despite the complex design of the gearbox, changing the oil in the gearbox is quite simple with experience and skill.
How often should the gearbox oil be changed?
How often do you need to change the oil in the rear gearbox? It all depends on the car model and operating conditions. Experienced auto mechanics will tell you that when standard conditions operation, oil change in the gearbox is required on average every 40-60 thousand km of run.
With intensive use of the car, over time, slow oxidation and decomposition of the filled oil occurs in the gearbox housing. The reason for this phenomenon is the ingress of heated air into an insufficiently sealed system. The inevitable decrease in oil viscosity during operation also has a negative effect.
Why do they pour m aslo in gear rear axle? Timely filling of oil fluid into the rear axle gearbox is necessary in order to improve the interaction of the unit parts, to extend their operational period. Usually, car parts break down due to wear and tear, poor maintenance.
Prevention of malfunctions makes it possible to prevent the occurrence of various malfunctions in the unit. You need to understand how the oil is changed in the transfer case and the rear gearbox, to be able to choose which oil to pour into the rear axle gearbox.
How does the rear axle work, why does it wear out?
The rear axle reducer (transfer case) is a unit combined with each other, transmitting torque from power unit to the wheels. The gearbox is subjected to different loads, the degree of which depends on the speed. In view of this, friction appears in him, which has a destructive effect on his state. In order to compensate for this effect, a special lubricant is used to soften the movement of the moving parts and ensure their integrity. Changing the oil in the gearbox is an important procedure that must not be neglected.
It is necessary to change the oil in the rear axle approximately every thirty-five thousand kilometers. This replacement frequency is recommended by renowned car manufacturers. There are certain signs, upon detection of which it is necessary to immediately replace the consumable (having previously determined which oil to pour into the rear axle gearbox). These include:
- reducing the amount of car oil;
- the appearance of gray dust in the lubricant;
- change the shade of the consumable.
The influence of harmful factors on the rear axle of the car
A decrease in the amount of lubricant may be due to a deterioration in its technical characteristics, leading to a change in the viscosity index. Also, the level of the consumable may decrease due to the usual leaks arising from increased loads.
The appearance of gray dust is a sign of worn parts. The outer layer of spare parts wears off over time, precipitates. Getting into the car oil, the sediment begins to circulate throughout the lubrication complex. If it gets on an important part, its holes may be partially blocked. This could lead to damage. Pour fresh lubricant into the gearbox immediately if this problem is detected. If you find metal particles, shavings in the car oil, then you need to overhaul the engine and completely replace the damaged parts.
A change in the color of a petroleum product from gold to black is considered a sign that the lubricant is functionally worn out. Prolonged use, high loads, dustiness - all this gradually leads to a deterioration in the performance of the car oil. The molecular structure of the petroleum product is disrupted. Such oil is incapable of efficiently lubricating parts.
If you find at least one of the above symptoms, replace the oil fluid immediately. You can use the services of a car service. Its employees will replace the car oil in a short time. transfer case... You will only need to pay them for the work. If you change the oil product yourself, you can save a lot (provided that the replacement is carried out correctly). However, changing the lubricant, it is difficult to make such a mistake that could completely remove vehicle out of service. The most dangerous thing that can happen is that you get burned with waste oil. If you are careful, this will not happen. You can save your money if you know how to fill the rear axle with oil.
Algorithm for changing the car oil in the rear axle gearbox
How is the oil change in the rear axle gearbox carried out? The algorithm is as follows:
Now you know how to change the oil in the rear axle of a VAZ (and any other car). Changing the oil in the rear gearbox is a fairly simple procedure.
Which car oil to choose?
What kind of oil to fill? It is possible to use both mineral water and synthetics. Due to its own composition, synthetics resist wear better than mineral water made through petroleum refining, which must be changed frequently. Plus mineral oil its rather small price is considered. Special additives are added to synthetics, which increase the operating period of such a car oil several times. However, the cost of synthetic consumables, especially from well-known manufacturers, is quite high.
Before deciding which oil to pour into the rear axle gearbox, remember that there are still semi-synthetic oil products. They are not as expensive as synthetic ones, while they have rather high technical characteristics(constant viscosity index, excellent lubrication performance). It is not for nothing that semi-synthetics have become so popular among many car owners in the Russian Federation.
The task of a gearbox in a car is transmit and distribute torque from the engine to the wheels. This function is realized due to the interaction of rotating toothed gear shafts, differing in the number of teeth. Depending on the ratio of the number of teeth at the gears, the gearbox can either decrease or increase the torque, depending on the design features of the car.
Obviously, the constant interaction of metal elements in the absence of lubrication would be extremely short-lived. Therefore, a significant role in the operation of the gearbox is played by transmission oil... It allows for optimal adhesion of the gear teeth to each other, reduces metal abrasion and, as a result, increases the life of the gearbox.
Performed, as a rule, simultaneously with the oil change in transmissions(and the oil itself coincides with the transmission oil), and its timely implementation is no less important for the gearbox than for the gearbox. For most cars, it is optimal to change the oil in the gearbox during the seasonal maintenance of the car (when changing from winter to summer operation and vice versa).
When is a gearbox oil change required?
Conventionally, there are three main reasons why it is important to change the oil in the gearbox:
- during intensive operation, thermal and oxygen exposure leads to the decomposition of hydrocarbons that make up transmission oil, that leads to metal corrosion;
- over time, the viscosity of the oil decreases, its properties deteriorate and, as a result, wear increases gear teeth of the reducer;
- in oil gradually wear products accumulate, which also impairs its lubricity and accelerates wear.
There are other situations in which changing the oil in the gearbox is recommended regardless of the mileage.
As a rule, the oil is changed upon purchase. "From the hands" of a used car if you do not have reliable data on the previous oil change (for example, in the form of a record in service book). Otherwise, there is a high risk of significantly exceeding the recommended replacement interval if the previous owner misleads you.
In addition, the oil is changed after serious renovation corresponding vehicle units (and, of course, after overhaul). Moreover, in this case, a repeated oil change is required after a break-in period (after 2-3 thousand kilometers, as in a new car).
Gearbox oil change intervals.
Define periodicity, with which the oil in the gearbox of your particular car should be changed will be easiest by studying the operating instructions. In the absence of such, you can focus on standard recommendations. Generally for vehicles with Manual transmission the recommended replacement interval is 50-60 thousand kilometers mileage. For vehicles with Automatic transmission mileage will be shorter by about half and will be 25-30 thousand kilometers.
It should be borne in mind that the frequency of replacement depends on the operating conditions of the car. In "difficult" conditions, the oil change in the gearbox must be carried out significantly more often.
To the conditions shortening the oil change interval in the gearbox, include:
- regular transportation of large loads, towing trailers or other vehicles;
- driving on unpaved country roads, driving with frequent slippage, driving on loose snow;
- driving for short distances with frequent braking and stopping (as a rule, this mode is typical for any metropolis).
When buying a new car, the manufacturer or dealer often notes the need for the first oil change after 2-3 thousand kilometers mileage. Such a short period is really justified. During the initial operation, intensive grinding of all vehicle units takes place, this process is inevitably accompanied by a significant formation of wear products. For the subsequent long-term trouble-free operation of the car, the oil must be changed after the first couple of thousand kilometers of running-in.
Self-change of oil in the gearbox
When changing the oil in the gearbox on their own, you need to pay attention to several nuances.
On most cars, changing the oil in the gearbox is not a laborious procedure (as opposed to repairing or replacing the gearbox itself), but it is optimal to perform it on inspection pit or overpass... This will allow you to install the car with the possibility of subsequent overhang of the wheel for flushing the gearbox.
The oil is drained when the engine is warm, so care should be taken when working to avoid burns as the oil temperature is very high. In this case, it is important to let the oil drain completely, since the heaviest suspensions remain in the thick sediment, which is the last to flow down.
On most vehicles, the drain plug design contains a magnetic part that attracts metal deposits. Therefore, when changing the oil, it is important to flush and drain plug.
If, upon external evaluation, the drained oil appears to be heavily contaminated, it is advisable to additionally flush the system special flushing liquid. Its density is much lower than that of ordinary oil, which literally allows to wash away the residues of dirt that have settled on the working surfaces of the gearbox.
After draining and cleaning, the gear unit can be filled with fresh oil.
As a rule, the oil change in the gearbox is carried out with an oil similar to the previously used one recommended by the car manufacturer.
In some cases, a car owner wishing to change the brand of the oil used can use the compatibility tables offered by the oil manufacturers. But, of course, it is most effective in this case to seek advice from specialists.
Also during maintenance, in addition to assessing the condition of the oil itself, it makes sense to pay attention to the condition oil seals gearbox, as through them oil can flow out of the gearbox.
Automotive gearbox is a transmission element that receives torque from the crankshaft and transmits it to center differential... Depending on the type of transmission, a distinction is made between gearboxes integrated into the gearbox. front axle(front wheel drive) and rear axle (rear wheel drive). For all-wheel drive models, respectively, both gearboxes are present. The transmission of torque through the gearbox is carried out by means of gear wheels rotating at a certain frequency. To prevent abrasion due to friction in the gearbox, gear oil is used.
When to change
There is no definite period for changing the oil in the gearbox. It is customary to pour new oil into the unit at the same time when other transmission elements are serviced and the rest are changed. transmission fluids... The standard period for servicing the transmission is 45 thousand kilometers, then every 60 thousand kilometers, or every 2 years of vehicle operation.
With intensive operation, the period for changing the oil in the gearbox is reduced to 30-35 thousand kilometers. These conditions include:
- transportation of heavy loads, towing trailers or vehicles on a cable;
- frequent driving in city mode (start - stop);
- operation in unfavorable conditions (off-road, in conditions of snowy roads, etc.).
In the manuals for the use of some models, it is indicated that the first oil change in the gearbox must be made after 1-2 thousand km of run. The fact is that at this stage, the vehicle components are lapped, which is characterized by increased friction and the formation of wear products.
How to check the oil level and quality
During the operation of the car, the oil in the gearbox loses its viscosity, and later oxidative processes occur as a result of the ingress of heated air due to insufficient tightness of the system. As a result, the oil decomposes and ceases to perform lubricating functions, there is an intense wear of the gear wheels and overheating of the gearbox.
Checking the quality and level of oil is carried out on an overpass or inspection pit - it is important that the surface on which the car stands is absolutely flat. The check is carried out, as they say, "cold", when all the oil is collected in the gearbox housing.
The first step is to unscrew the filler plug using a hexagon. If, after unscrewing, a certain amount of oil spills out, its level in the crankcase is sufficient. If no oil is pouring out of the filler hole, then you can check its level by inserting a finger, stick, wire, etc. into the hole. Ideally, the oil level should not be lower than a few millimeters from the bottom edge of the filler hole. If the distance is greater, the oil level is insufficient. You can check the quality of the lubricating fluid by pumping out a small amount of oil with a syringe and evaluating it. appearance and consistency.
What oil to fill in and how much
Suitable for filling is the gear oil recommended by the manufacturer in the user manual. If the manual is not available, and the car owner is not firmly sure which gear oil is suitable, then you need to focus on the API classification and viscosity indicators.
All manufacturers recommend using on modern cars transmission oils numbered GL-4 or GL-5 - these are the fluids that contain the necessary extreme pressure additives. As for the viscosity, the choice here depends on the climatic conditions of operation. For transmission oil, it is advisable to choose all-season options - hardly anyone will change the oil in the gearbox for one season. Such products are indexed with double numbering, for example, 75W-90, where the first digit indicates the viscosity at negative temperatures, the second - the viscosity during summer operation. The lower the first digit, the lower the temperatures at which the transmission oil retains its viscosity. For example, 70W oil can be used at extreme temperatures of -55 ° C, 75W at -40 ° C, 80W at -26 ° C, etc.
As for the required volume, for passenger cars with a drive on one axle, usually 1-2 liters of transmission are enough. For vehicles with four-wheel drive and two crankcases may require 3 liters or more. For commercial vehicles, the required volume of transmission oil can be up to 10-15 liters. Before filling, it is advisable to stock up on an additional volume (up to 1 liter), since you may additionally need to flush the gearbox.
Oil change instructions
It is advisable to change the oil after a short trip - it will allow the oil to warm up and become less viscous. To carry out the operation, again, it is advisable to use a lift or a viewing hole - this will facilitate access to the gearbox.
- The first step is to drain the old gear oil. To do this, unscrew the drain plug with a hexagon. The used oil must be drained into a previously prepared container.
- When draining, you should pay attention to the consistency and appearance of the waste fluid - if it contains impurities in the form of metal inclusions, then before pouring a new transmission, you will have to flush the gearbox.
- Then it is necessary to remove the plug from the filler hole of the gearbox housing with a hexagon.
- A large medical syringe or lever pump (grease gun) can be used to pump new oil into the gearbox.
- The gearbox must be filled with oil until it overflows. When using a grease gun, it will take 10-15 minutes, when using a syringe, a little more time.
- After filling, wipe off the remaining oil from the gearbox and fit the plug filler neck on the sealant.
Gearbox flushing
To flush the gearbox, special flushing fluids are used (Loctite 7840, DS Lavado, etc.). Alternatively, you can use a mixture of gear oil (70%) and kerosene or diesel fuel (30 %).
This mixture must be poured into the gearbox housing using a grease gun or a syringe. Then you should hang out the wheels of the drive axle using struts, start the engine and engage the first gear, simulating a trip. In this mode, let the engine run for 10-15 minutes, allowing the flushing mixture to clean the gearbox. After that, the mixture should be drained in the same way as used transmission oil was drained.
In the process of replacing the gear oil in the gearbox, you can at the same time assess the condition of other parts and consumables, for example, axle oil seals. It is the wear of the oil seals that can cause the oil level in the gearbox to be low. If any gland leaks are found, they should be replaced with new ones.
