Oil flows between the engine and gearbox: diagnostics and repair methods. Why is oil flowing between the engine and gearbox? How to fix the problem Oil runs between the box and the engine

Many motorists are faced with the fact that there was an oil leak between the engine and gearbox. Of course, as practice shows, everyone goes to a car service in order to determine the reasons there.

But, often, along with existing malfunctions, car service workers also attribute those that do not exist. Therefore, it is worth understanding the causes of the breakdown, as well as how to eliminate it.

Symptoms

Before proceeding directly to the analysis of the reasons, it is worthwhile to understand that oil leaks formed precisely between the internal combustion engine and the gearbox. The first direct sign is the appearance of an oily spot on the asphalt. Of course, an oil leak from an engine can come from anywhere. Therefore, it is worth diagnosing the malfunction in more detail.

To determine that oil is flowing from the engine, you must first remove the dipstick of the lubricant level from the engine and inspect where the oil mark is. According to the technical documentation, for almost all automakers, the power unit's lubricating fluid level should be between the maximum and minimum marks, somewhere in the middle.

If the indicator has dropped significantly, then there are either oil smudges on the engine, or fluid is leaving between the engine and gearbox.

For a more accurate diagnosis, it is necessary to install the vehicle on a pit or lift and inspect from below. Since many vehicles have engine protection, it must be dismantled. After dismantling, it will immediately become clear where the oil leaves the engine. An oil stain will form between the gearbox and the engine and smudges will be visible.

Also, an indirect sign can be considered that oil stains were found under the car, and the clutch began to work hard, while the gears are switched with difficulty. It can be assumed that oil has squeezed out onto the disk and it is wet. This makes it difficult for the transmission to work.

Causes of the problem and solutions

Why is oil flowing? First of all, due to the loss of the sealant of its qualities. So, it is worth noting that the lubricating fluid can flow not only from the engine, but also from the gearbox, which is even more dangerous, since on most cars it is impossible to set the actual oil level in the transmission.

To make sure that oil flows between the engine and the gearbox, the already installed car in the pit should be disassembled. So, the engine protection is dismantled, and behind it the bolts connecting the gearbox and the internal combustion engine are unscrewed.

It is in the clutch pan that there is enough oil, and the drive disc will be all wet.

So, the first thing that throws itself under suspicion is the crankshaft oil seals. These elements can quite simply fail, even after 100 km of run, since it is impossible to immediately determine their quality. To fix the problem, you will have to sweat, because in order to replace the crankshaft oil seal, it is often necessary to dismantle the pan.

Although, most motorists and engine repairers do not. If we take into account such cars as the Volga, then instead of the stuffing box, an stuffing box is installed from which the lubricant will actually leak into the clutch housing.

The wear of shafts and seals also becomes a fairly common cause of a malfunction. This applies not only to the engine, but also to the gearbox. The input shaft is the first to be suspected, especially when it is an automatic transmission. In this case, it is necessary to replace the thrust bearings and inspect the housing for wear. If in this case everything is fine, then it is worth replacing the input shaft.

Also, the cause may be the wear of the sealant, which coats most of the joints of metal parts. If it is worn out, then the oil can easily squeeze it out and a leak forms.

If an inexpensive domestic motor oil is poured into the car, which does not have the best technical characteristics, then it will easily leak out, especially while the car is moving. Replacing the sealant can solve the problem of leaving the lubricant, but for this you will have to disconnect the parts where the leak has formed.

Perhaps one of the common reasons why oil leaked between the engine and transmission is the loosening of the fastening bolts of the connection in the engine, namely between the sump and the cylinder block, where the crankshaft is attached. To eliminate the causes of the leak, it is worth tightening the bolts and inspecting the sealing joints.

The wear of the block housing in the seat of the crankshaft bearing, in this case, it is worth carrying out repair and restoration operations on the housing or choosing a bearing of a larger diameter.

In this case, it should be borne in mind that you will have to adjust the body to the part, for this it will be necessary to make a groove of the mounting and installation seat.

Consequences of late repair

Why oil leaves the engine and where it is determined. Now it is worth considering the consequences of untimely repairs. As you know, an engine without oil cannot move, since oil not only performs lubricating properties, but also has cooling properties. Therefore, the consequences of a low oil level in the engine will be fatal, especially during long-term operation of the power unit. Consider the main consequences:

• Increased wear of the crankshaft and piston group. Thus, an insufficient oil level can lead to the fact that the output will be significantly higher.
• Increased wear of parts will lead to the appearance of a large amount of metal chips in the lubricant residue, which will further increase the degree of wear of parts. So, the seals and sealing elements are the first to be worn out.
• Also, a low oil level, both in the box and in the engine, leads to the fact that the motor overheats greatly, and accordingly, there is a possibility that the motor will overheat and the head of the block will receive deformation or deflection.

Conclusion

The main causes and methods for eliminating leaks between the gearbox and the engine are determined. Also, it is worth noting that due to the high level of lubricating fluid in the engine and pressure, the oil can put pressure on the sealing elements that will not withstand and depressurization will occur. The consequences of untimely repairs can also be quite severe and lead to a major overhaul of the power unit.

During the operation of the vehicle, the driver may notice an oil leak between the engine and gearbox. We note right away that a similar malfunction appears on different cars, and no matter what type of engine (,) and gearbox are installed.

In other words, oil leaks at the transmission junction and on different cars when the car is equipped with a manual transmission, a manual transmission, a robotic gearbox with one or two clutch discs, a manual transmission, an automatic transmission with an automatic transmission torque converter, a continuously variable variator, etc.

In any case, if oil drips between the engine and gearbox, then this is a sign of a serious breakdown. Faults of this kind require immediate diagnosis and quick elimination.

Next, we will talk about why an oil smudge may appear between the power unit and the gearbox, and also what the driver should do if smudges of fresh lubricant are visible between the engine and the gearbox, oil is actively running or the lubricant on the parts is covered with dust (the leak is insignificant, there is fogging).

Read in this article

Oil flows between the box and the motor: why is this happening

For a better understanding and quick identification of the problem, let's start with the features of lubricating fluids in gearboxes and internal combustion engines. The fact is that the operating conditions of the transmission and the power unit are significantly different. For this reason, engine oil is poured into the engine, and special transmission oil is poured into the gearbox. For both the motor and the gearbox, the lubricant may have.

However, this is where the similarity ends. Please note that these fluids differ greatly in their basic properties (viscosity) and chemical additive packages. This is due to the fact that in the engine, lubricant is supplied to loaded components and parts under pressure, and to elements with lower loads it is supplied by spraying.

At the same time, engine oil becomes very hot, subject to oxidative processes, etc. In most transmissions (except for torque converter automatic transmissions), mating parts are lubricated by spraying lubricant during the rotation of the nodes, the loads on parts inside the transmission are much less compared to internal combustion engines.

Such features of work also determine the overall service life of lubricants in each unit (on average, 10 thousand km for engine oil and 50-80 thousand for transmission oil). We also note that for each node, the vehicle manufacturer determines individual tolerances for viscosity and other lubricant parameters.

The viscosity of the engine or transmission oil is not suitable

Now back to our main problem. It is quite obvious that if a leak appears between the gearbox and the engine immediately after switching from a “thicker” SAE oil to a low-viscosity lubricant (for example, mineral water was replaced with liquid synthetics), then there is a high probability of a banal mismatch of the filled material with the recommended parameters.

Simply put, the use of low-viscosity lubricants in gearboxes and internal combustion engines can lead to leaks. So what does this information give us? Most importantly, if the oil in the motor or gearbox turns out to be unsuitable, then leakage can be easily eliminated by replacing the lubricant with the recommended one.

If no other prerequisites for the appearance of leaks have been identified, then it is appropriate to talk about a malfunction. At the same time, the analysis of the oil itself allows you to determine where it flows from, from the box or the engine. Let's dwell on this in more detail.

There was a malfunction in the internal combustion engine or gearbox: how to accurately determine

If the liquids poured into the engine and gearbox meet all the parameters, then oil leakage at the junction of the engine and gearbox is the result of a breakdown of one of these units. Less often, but it is quite possible that problems can occur simultaneously in both nodes at once.

As already mentioned, the lubricant in the gearbox and internal combustion engine differs in consistency, color and smell, which allows us to draw some conclusions. For primary diagnosis, this is very important, since it is possible to more accurately determine which unit leaked and why. To do this, you need to carefully examine the streaks, the color of the oil, dust and dirt on it.

Now let's move on to verification. We note right away that limited access usually prevents the exact cause from being determined. In other words, it may not be possible to visually inspect the junction of the engine and box. In such a situation, the easiest way to determine where the fluid is flowing from is.

To do this, the level is estimated by the dipstick, a decrease in the indicator will indicate problems with the motor. We add that the gearbox on some cars may also have its own oil dipstick. However, such a check allows you to accurately determine the problem unit when the oil flows out intensively. In this case, you can usually also notice oil stains under the front of the car.

If only streaks were found on surfaces and parts at the junction of the transmission and the power unit, then the lubrication level does not always drop significantly. In such a situation, an additional assessment of the leaking fluid helps.

Motor oil has a lighter reddish-amber hue, it is fluid, its smudges conditionally “absorb” dust and dirt. Transmission oil is usually darker, may have a reddish tint (ATF oil). Such a lubricant is thicker, has a characteristic pungent odor, smudges quickly become overgrown with a thick layer of dust, accumulating dirt on its surface in the form of a “fur coat”.

Note that the following method is also often used in practice. Part of the flowing liquid must be collected in a container into which water was previously filled. When it enters the water, engine oil coagulates, retaining the shape of a drop, after which it sinks down. The transmission fluid does not sink to the bottom, spreading over the surface in a spot.

Oil leaks from the engine or gearbox: the main causes and repair

The appearance of various leaks at the junction of the gearbox and engine most often occurs for the following reasons:

• wear or failure of oil seals (for example, crankshaft rear oil seal);
• there were various defects of shafts and seals;
• the appearance and increase in the backlash of the shafts (primary shaft, etc.);
• there was a weakening of the fasteners;
• seals and gaskets have lost their properties;
• there was a depreciation of the stuffing box on the input shaft of the box;
• the main oil seal may be worn out;
• during repair, the oil seal or gasket is incorrectly installed;
• the geometry or integrity of the pallet is broken;
• oil squeezes out as a result of problems in the crankcase ventilation system;
• there was a depreciation of the shafts at the junction of the box and the engine;
• the oil pump or torque converter in the automatic transmission is out of order;

First of all, you need to determine where the oil is flowing from. Then you can proceed to find the cause and troubleshoot.

Lubricant is leaking from the engine

Let's start with the powertrain. As a rule, a leak often occurs in case of problems with . The specified element usually fails on units with solid mileage.

The crankshaft seal is made of oil resistant rubber. However, during operation, the part loses elasticity and hardens, and can also be squeezed out as a result of wear of the crankshaft thrust rings. As a result, after the engine warms up, the oil flows out.

We also note that problems with the crankshaft rear oil seal can be caused by a situation when the car is idle for a month or more without starting the power unit. The fact is that during such downtime, all the lubricant drains into the crankcase, the seals become dry, they are deformed or destroyed.

Also, a leak from the internal combustion engine occurs due to the fact that pressure rises in the crankcase of the engine. An increase in pressure is usually associated with the fact that there is an intensive breakthrough of exhaust gases from the combustion chamber through worn ones, and overall wear is additionally affected. Another reason could be that the crankcase ventilation system is not working properly due to contamination.

We add that a situation with increased pressure may also arise in the checkpoint. If the pressure rises, then the seals, gaskets and seals cannot cope with the load and allow the lubricant to pass out. Lubricant can flow out very actively, which increases the risk of a more serious breakdown of the problematic unit. In other words, if the problem is not fixed in a timely manner, then a gearbox overhaul may be necessary.

It is important to understand that oil leakage through the rear oil seal can lead to a rapid decrease in the level of lubricating fluid in the crankcase. On manual transmissions and manual transmissions, lubricant from the motor can also get on, causing loss of traction, slipping and jerking while driving.

If these symptoms match those on the dashboard, then it is urgent to check the level of lubrication in the engine. Drips in the area of ​​\u200b\u200bthe junction of the box and the internal combustion engine will indicate that it is urgent to replace the rear crankshaft oil seal.

As for the crankcase ventilation, then it is necessary to check the oil deflector in the valve cover and assess its condition. If a dark brown or bluish coating is noticed, then this is a sign of problems in the ventilation system. To confirm the diagnosis, you need to unscrew the oil filler cap, and then cover the hole with a sheet of clean cardboard.

Then the engine can be started and idling, raising the speed to 900-1100 rpm. If the cardboard is pressed tightly against the neck, then the ventilation system is working properly, that is, a vacuum is created in the crankcase. If this does not happen, then the nozzles and other elements of the system need to be cleaned, purged or replaced.

Oil is leaking from the gearbox

As mentioned above, the lubricant found during the inspection at the junction of the box and the motor can be both engine and transmission oil. To begin with, manual transmissions rarely leak in this area, since the oil in them is below the input shaft bearing. Such boxes are more likely to leak grease in the area of ​​\u200b\u200bthe gasket of the gearbox pan cover or from the breather.

Most often, oil leakage between the engine and the gearbox occurs on machines with automatic transmission. Oil in such boxes is supplied to mating parts not by spraying, but under pressure, which creates an oil pump. In other words, the pressure inside the automatic transmission is higher.

Often, oil from the automatic gearbox flows between the automatic transmission and the engine due to a faulty torque converter. As a rule, its malfunction occurs along with the failure of the oil pump. In this situation, an expensive repair or complete replacement of the automatic transmission is necessary.

We also note that in some cases, lubricant leakage is accompanied by foaming. The appearance of foam in the gear oil can occur both as a result of overfilling or a decrease in the level, and after filling in a lubricant that does not meet the tolerances and requirements. This is also true for the engine oil in the internal combustion engine. If the dipstick shows that the oil level in the engine or gearbox is above normal, then you need to remove the excess.

As for the automatic transmission, it is forbidden to add oil to such a box, which differs in properties from the previously filled one. In other words, you can't. To switch to other fluids, you must first or gearbox to remove the remnants of the old grease. After that, a complete one is produced in a box or engine.

Note that in many cases, even a serious repair of the automatic transmission may not bring the desired results, and the costs of such an operation will be quite high. For this reason, it is optimal to carry out a complete diagnosis of this unit, after which you can decide what will be more profitable, repair or replace the box with a contract or a new one.

Also, in the process of diagnosing automatic transmissions or other types of boxes, it should be borne in mind that oil leaks can occur for a number of reasons, which are quite easily and quickly eliminated. This means that it is not necessary to remove the box immediately.

For example, even a loosely inserted dipstick to check the oil level or an insufficiently tightened drain plug will cause a leak. Grease may also leak at the installation sites of various sensors. A common cause is insufficient tightening of the specified elements, damage to the sealing rings at their installation site, etc.

If grease leaks through the sensors, this indicates that the rubber seal is damaged, kinked, or has other defects. The sensor itself can also be destroyed. In this case, the device is replaced with a new one or only the sealing element is replaced (if possible).

The appearance of malfunctions or noises clearly indicates both breakdowns and problems with the lubricant (insufficient or high level, loss of properties, non-compliance of the lubricant with tolerances and requirements, etc.).

For example, if the box is buzzing in neutral gear, then the bearing on the drive shaft may fail or the gear oil level has dropped. If the problems are related to the synchronizer clutch or blocking element, then the noise in the box appears when driving in a certain gear (more often at high speed, 3 speed, 4, etc.).

A hum from the box may also appear when the gearbox mount is loosened. Insufficient clutch pedal depression or problems with this unit (especially on cars with a single-disk "robot" manual transmission) cause a crunch, jerks, jerks, and difficult switching. In this case, the parts experience increased loads, after which defects occur, oil appears at the junction of the box with the motor.

If the situation is emergency, that is, a lubricant leak appeared on the road and there is no way to put the car in for repairs, then many drivers try to stop the leak with the help of special additives. As a rule, softening sealants of the “stop-leak” type contain components that allow the sealing elements to return elasticity.

In other words, it is possible to restore the tightness between the shafts and the seals for some time. This allows you to get to the place of repair of the vehicle on your own. So, we strongly do not recommend using such solutions both in the engine and in the gearbox.

First of all, the additive does not remove the wear of parts, that is, the breakdown itself not only persists, but also progresses. Also, this method is not suitable for large leaks. Moreover, the additive has a serious effect on the lubricant and on the parts themselves inside the assembly. Otherwise, the addition of an additive worsens the basic properties of engine or transmission oil, clogs the engine and gearbox lubrication system.

A frequent result is that after disassembling the unit, into which such additives were previously poured, complete unrepairability or significant wear is found not only of the initially problematic, but also of other structural elements.

For this reason, it is better to choose the right lubricant for topping up and use it as needed than to buy sealants and additives. Also, auto mechanics and experienced drivers do not recommend switching to a thicker lubricant after detecting leaks, which is not recommended by the vehicle manufacturer or does not correspond to the operating conditions of the car.

The same can be said about special oil thickeners. Although this approach in some cases can reduce or eliminate leakage, however, the lubrication of mating loaded parts also deteriorates. As a result, the wear of engine or gearbox parts is greatly increased.

Summing up

A fairly common situation is that the driver may not notice the problem for a long time, especially if the oil seals, gaskets and seals do not flow, but “sweat”. In other words, the level of lubrication is reduced, but gradually. The danger is that the unit is still subject to wear, and sooner or later a strong leak may open. In this case, the gearbox or engine will be left without oil in a matter of minutes.

For this reason, it is important to pay attention to the appearance of noise and knocks in the engine and transmission. For gearboxes (especially automatic transmissions), it is also impossible to ignore difficult shifting, the appearance of jerks, shocks or delays when shifting gears. As for oil leaks, it’s not worth delaying repairs in this case.

Leaking grease not only pollutes the gearbox and internal combustion engine, but also gets on other elements in the engine compartment, having a negative impact on them. Also, you should always remember that a decrease in the level of lubrication in the engine or gearbox quickly leads to wear and further breakdowns of these units.

Lubricating fluid is one of the main components that ensure the performance of a car, so its level and condition must be carefully monitored. Having found signs of oil leakage from the engine or gearbox (gearbox), you must immediately identify and eliminate the cause that caused the problem. This will avoid serious troubles associated with the failure of the power unit directly during the trip and will postpone the period of forced expensive repairs for a long time.

Signs of an oil leak

Oil leakage from the power unit of a car is a common phenomenon that is well known to many drivers. The very design of the engine contributes to the occurrence of this problem - it uses many sealing elements (gaskets or seals), through which the lubricant flows. Signs of fluid leakage, in addition to a decrease in its level, which can be determined with a dipstick, appear in the form of oily drops, streaks and stains on parts or under the bottom of the machine. Problems in the lubrication system are also indicated by the appearance of gray (blue) smoke from the exhaust pipe or from under the hood of a car.

Photo examples

Engine covered with black oil Oil drops appearing from the bottom of the engine Gearbox parts covered with oil stains Oil streaks appear on the engine housing The bottom of the engine is oiled Oil stains under the bottom of the car indicate a leak

Where is the grease leaking, dripping or running from?

This question is asked by every motorist who has discovered an oil stain under the bottom of his car. The first thing that comes to mind is problems with gaskets or cuffs, but which ones? The fact is that oil can flow from the engine itself or from the gearbox, where the input shaft oil seal (manual transmission) or fluid coupling (automatic transmission) is located. How is the source of the leak determined? Experienced craftsmen distinguish gear oil by smell, but for everyone else we will advise a simpler way: place a particle of leaked grease in a vessel with plain water - the motor oil will go to the bottom in the form of a drop, and the transmission oil will “run up” over the surface.

Attention! Only by determining where exactly the oil is flowing from can further steps be taken to solve this problem.

Causes of the malfunction and how to eliminate them

An unnoticed oil leak in time can lead to serious damage to the power unit. To fix the problem and prevent further leaks, it is important to know the causes of their occurrence. So, the malfunction can be caused by:

1. Insufficient crankcase ventilation of the unit. The problem is typical for heavily worn engines and gearboxes. The ventilation ducts of such assemblies are very dirty - this creates increased pressure in the crankcase and leads to the displacement of lubricant through oil seals, cuffs or gaskets, oil can drip quite abundantly.
2. Excessive amount of lubricating fluid poured into the unit. An excessive amount of oil contributes to an increase in oil pressure in the system. At the same time, seals and gaskets do not withstand the increased working pressure and “break through” (start to leak).
3. Wrong choice of lubricant. Long service life of oil seals and gaskets is ensured by the type of lubricant recommended by the vehicle manufacturer. The use of another, even better quality oil leads to the destruction of the sealing elements.
4. Long (more than a month) downtime of the car. Gaskets and seals can fail if the engine does not warm up for more than four weeks - all the oil drains into the crankcase, and the seals that are left without lubrication dry out and collapse.

In addition, leakage of lubricating fluid occurs due to defects:

• oil pan;
• intake manifold;
• oil filter;
• distributor;
• oil pressure sensor.

Attention! If the low oil pressure indicator on the instrument panel comes on, the vehicle must not be operated.

Let us consider in more detail those components and assemblies of the car, the malfunction of which can cause oil leaks.

Engine

Lubricant leaks are a serious test for anyone, especially a novice driver. Note that it is rather difficult to eliminate the causes of blue smoke from the muffler on your own. It is no less difficult to eliminate oil leakage due to severe wear of the shaft or the cylinder-piston group of the engine - with such problems it is better to immediately contact the service station, where experienced craftsmen will quickly and efficiently repair the motor. Today we will talk only about those defects that can be eliminated with your own hands.

Crankcase ventilation system

Modern car engines are equipped with "dual" crankcase ventilation: the first part of the system operates at high crankshaft speeds, the second - at idle. This equipment includes:

• An oil deflector valve that prevents oil vapor from entering the engine combustion chamber. If the device becomes clogged with soot, its normal operation will be disrupted - oil will penetrate into the air filter and then into the intake manifold. The car's engine will start to "smoke" a lot.
• A ventilation valve that regulates the pressure of gases that enter the manifold. In idle mode, the device is in the open state, closing smoothly with increasing speed. Incorrect operation of the part leads to a lean mixture, causing interruptions in the engine.
• Tight rubber tubes that remove excess gases that enter the crankcase. These elements are ventilation channels; clogging with slag and fumes, they disrupt the normal operation of the system. Exhaust gases create excess pressure, which leads to the fact that most of the seals, unable to withstand such loads, are destroyed and begin to pass the steam-oil mixture.

If the ventilation channels 2 and 3 are contaminated, the pressure in the system may increase and the gaskets may break.

Crankcase ventilation should be checked first, paying special attention to the condition of the oil slinger valve installed in the valve cover. You can verify that the system is working as follows:

1. Remove the oil filler cap.
2. Close the mouth with a piece of thick cardboard.
3. Start the car engine.
4. Bring the number of revolutions of the crankshaft to 1000 rpm.

Attention! The ventilation system works normally if the cardboard is pressed tightly against the neck due to the vacuum that forms in the engine crankcase. Otherwise, all rubber tubes that make up the assembly should be cleaned of internal deposits or replaced with new ones.

If oil leaks from under the valve cover, it is removed and thoroughly cleaned of internal carbon deposits or deposits.

Oil leakage from under the valve cover is eliminated by cleaning deposits

In addition, you will need:

1. Wash the oil separator valve of the crankcase ventilation system and the mesh in it.
2. Replace the rubber seal, having previously lubricated it with sealant on both sides.
3. Lubricate the rubber washers that are installed under the bolts that secure the cover with sealant.
4. Replace the valve cover and tighten the fixing bolts.

Scheme of fastening bolts

Attention! When tightening the mounting bolts, care must be taken - excessive force may damage the surface of the cover or strip the threads.

Having found that the liquid is running from under the oil filter, the part should be tightened more tightly. Usually, an oil leak in this place can only occur when a defective device is installed, so the correct solution would be to completely replace it.

Oil leakage from under the filter housing can only be eliminated by replacing it

Attention! The collapsible filter should be changed at the first sign of a malfunction - in most cases, even a slight leak can lead to the complete destruction of the part body.

Pressure meter

Leakage from under the oil pressure sensor is eliminated in the only way - by immediately replacing the device. The urgent need to perform these actions is due to the fact that the cause of the malfunction here is the wear and tear and violation of the integrity of the rubber diaphragm located inside the part. The element can break through at any time - then the oil pump will drive all the lubricant out of the engine through the sensor in a few minutes.

The problem of oil leakage from under the pressure sensor is solved by urgent replacement of the device

Attention! Most oil pressure sensors produced by the same manufacturer differ only in the design of the connector and can be interchanged.

distributor

Eliminating a leak that has arisen from under the cover of the distributor is not difficult. To do this, follow these steps:

Attention! Install the distributor so that the slider takes the same position as before the dismantling procedure.

Pallet

Oil flows out of the engine crankcase only after the pallet hits the unevenness of the road surface.

Leaking engine oil pan to be straightened

In case of critical damage, the part must be replaced, but if the pallet simply “stretched” on the fixing bolts, then it can be straightened (straightened). This will require:

1. Drain the oil from the engine.
2. Unscrew the fixing bolts and disconnect the part from the crankcase.
3. Thoroughly clean and rinse the pan from all kinds of deposits and dirt.
4. Align (straighten) the surface.
5. Apply sealant around the contour of the part and install it in place by tightening the fixing bolts.

Attention! It is required to tighten the bolts during the installation of the pallet evenly and with extreme care - you can easily strip the threads and break off one or more fasteners.

Oil seals

Any modification of an automobile engine is equipped with two sealing gaskets - crankshaft oil seals, framing the mechanism in front and behind. The development of the working life of parts or excess pressure of crankcase gases can cause oil to flow through these elements. Note that the elimination of this malfunction is carried out only by replacing the seals.

Oil leakage through shaft seals

Depending on the design of the motor, the front “frontal” oil seal is mounted in the cylinder block cover or the oil pump housing. To replace it, you will need:

To eliminate oil leakage through the crankshaft rear “main” oil seal, you will need to dismantle the cardan drive, disconnect the gearbox and clutch cover. The clip in which the sealing element is installed is removed as follows:

In a car engine, there are other seals that can leak - gas distribution shaft seals or oil pump shafts. The replacement of these elements is carried out in the same way: they are lubricated with lithol and installed with a spring inward.

Any car uses oil. And it doesn’t matter if it’s a diesel or gasoline car, automatic or manual. Often, with prolonged use, the oil loses its level. It can not only enter the combustion chamber, but also leak at the sealing points. And the engine oil doesn't always leak. Transmission is also not immune from this. What to do if oil flows between the engine and gearbox? In today's article, we will look at this issue in detail.

How engine and transmission components are lubricated

The engine and gearbox use different types of oils. In the latter case, it is more viscous. Unlike a manual transmission, the engine and automatic transmission are lubricated by forced fluid supply. This function is performed by the pump.

As for the mechanical box, here the oil enters the teeth by spraying. The gear, located in the transmission case, scoops up the fluid, and thus the teeth are lubricated at the point of contact. Another feature is the oil change schedule. For internal combustion engines, it is 8-10 thousand kilometers, and for automatic transmissions - 70 thousand. As for the mechanics, on most machines it is maintenance-free. That is, oil is poured for the entire period of operation. But this does not mean that you can not check the level of its balance. If the gearbox is leaking, it can cause increased gear wear. Eventually, she will fail. When replacing, you do not need to pour above the norm. Excess liquid will simply flow out of the “weak” places.

Engine or gearbox?

If oil flows between the engine and the gearbox, you need to determine from which node it disappears. If it is a thick fluid, then it is transmission fluid, and the problem is in the gearbox. If the car is more than 10 years old, it should be checked. Due to wear and constant vibrations, it is squeezed out and leaks oil. You can also crankcase. To do this, you can bring a piece of paper to a previously removed pipe. If at engine speeds over 1 thousand it does not bend, the system is clogged. In this case, there is an increased pressure in the engine lubrication system and the liquid begins to flow, as they say, from all the cracks. The weak point is the junction with the gearbox. The transmission also has its own ventilation.

It is carried out through the breather. If it is clogged, the pressure level inside increases, and an oil leak occurs between the engine box. VAZ-2110 is no exception. The solution is to clean the ventilation ducts and replace the stuffing box. When installing the latter, it is recommended to install the second one, regardless of the state, since its resource is also limited.

Banal reasons

Why is oil leaking in the box? The reasons may be trivial.

This is a loose drain plug or unscrewed sensors. Sometimes a leak occurs due to a loose dipstick. Here, leaks can be seen without dismantling the box and repaired on site. But what to do if these parts are tight, but oil still flows between the engine and the box? Let's consider further.

Serious malfunctions

There are a number of reasons for an oil leak that require the dismantling of the box. The first is the breakdown of gaskets and other sealing elements. It could also be a seal. But if in the case of the engine it is the crankshaft, then the sealing element of the input shaft flows in the transmission. Why is oil still flowing between the engine and gearbox? This problem occurs when the pallet geometry is violated. This often happens when hitting a large hole or other obstacle.

As a result, the pallet hits the box and deforms. If this is an automatic transmission, the reason is the breakdown of the "donut" ( torque converter) or in a faulty oil pump. The box itself goes into emergency mode. The car only works in 3rd gear.

About additives

Now in the automotive world there are many additives. And some car owners, deciding how to fix oil leaks, run to stores for a “miraculous” additive. They pour it into the engine or box (and most often both there and there) and wait for the effect. But as practice shows, it does not give any results. The additive is not able to eliminate mechanical damage to the pallet, “glue” the torn gasket and restore the squeezed out oil seal. The problem does not leave the car owner. The only thing that can reduce the effect of a leak is oil thickeners. Thus, you intentionally change its characteristics.

But this is very harmful to the engine and gearbox, and leaks will not be 100 percent eliminated. Therefore, it is necessary to repair the manual transmission, change the seals and gaskets. Feedback from car owners does not confirm the effectiveness of the additives.

How does the rear seal change?

This procedure is quite complicated, since the element is located behind the clutch system. If this is removed the driveshaft. Further, as on front-wheel drive, there is a box, a clutch assembly with a basket and discs, as well as an engine flywheel. The rear oil seal itself is installed in the housing and secured with eight bolts. After unscrewing them, we take out the case and press in a new element. If you have difficulty installing it, you can use a rubber mallet or an ordinary steel one, using a soft gasket. The latter can be made from a piece of an old car camera. Further, all the elements are assembled in the reverse order.

Front

It is much easier to change than the rear one. The element is located at the end of the crankshaft (on vehicles with a transverse engine - near the right pillar). To replace, we need to remove the timing belt cover and put the piston of the first cylinder at TDC. We loosen the tensioners and remove the timing belt, as well as the generator, after removing the pulley. Drain the engine oil. Dismantle the crankshaft pulley. Unscrew the oil pump. An oil seal will be pressed inside it. You can remove it with a minus screwdriver. The new one is pressed in using a large head (27 and above) or on a special machine. Further assembly is in reverse order.

About the selection of oil seals for gearboxes

When buying, you need to consider what kind of oil you will pour into the box in the future.

There are oil seals with different elasticity - for mineral and synthetic products. If you pour the wrong oil into a box, such an element will begin to crack. Usually this happens with "synthetics". It has good flushing properties. Note that for automatic transmissions there is a separate range of oils with a certain viscosity. Their properties differ significantly from manual transmission fluids.

Keep your engine clean

After replacing all the elements, it is necessary to carry out an external engine wash. So you eliminate the old places of oil leakage and you will know from which places it will flow in the event of a malfunction. It is advisable to wash the motor and gearbox once every two years. Don't be afraid to point the jet of water at the engine. The only thing is to ensure the tightness of the ignition elements. This is a coil, distributor, candles, and the ingress of moisture on them is highly undesirable.

Summary

Thus, if a leak occurs between the box and the engine, you should not postpone repairs. Whether it's manual or automatic, it doesn't matter. Driving with low oil equally kills these boxes, not to mention the engine itself. Well, to control the level daily, crawling under the bottom and taking out the dipstick (if it is a box) is just madness. With a one-time financial investment in repairs, you will forget about the leak for several years. And remember that by using oil thickeners you are not solving the problem, but just hiding it.

Keep an eye on the car for leaks when it is parked. The presence of oily drops under the bottom is the first sign that you have oil flowing between the engine and gearbox.

As a rule, the driver finds out that oil is flowing from the gearbox by finding characteristic fluid leaks on the ground under his car. Naturally, an oil (ATF) leak is a sign of a breakdown, so in order to find out why oil is leaking from the gearbox, you need to pay special attention to finding out the cause.

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Why is gearbox oil leaking?

Having found the first signs of oil leakage from the gearbox, or between the engine and the gearbox, you should quickly find out the defective place. An oil puddle can be seen under the hood of your car or under the bottom, but for this it will be more convenient to drive the car onto a flyover. In any case, if the liquid drips, this flaw must be disposed of.

Sometimes it is very difficult for a driver, especially if he has been driving recently, to determine the very defective place. This is mainly due to the fact that the process of finding a fluid leak from a box or between an engine and a box can complicate a number of circumstances, as well as limited access to most of the weak points of the box. Based on practice, it can be assumed for what reasons a liquid flows or drips:

• unsuitability of seals;
• wear of shafts, which, one way or another, are associated with sealing elements;
• non-standard backlash of the automatic transmission input shaft;
• the need to replace the sealing layer;
• loosening the bolts connecting the elements of the box;
• seal failure.

Adding fluid to automatic transmission

If you notice that the seals on your automatic transmission are really old but dry, it is best to replace them immediately so that they do not become the next source of leakage. If the problem is with the seals, they should also be replaced.

To replace the oil seals of the drive shafts of the wheels, you need to proceed in stages:

1. First you need to drain all the oil from the box.
2. Then it is necessary to rinse the box with kerosene or diesel fuel so that the remnants of the old liquid do not remain on the walls.
3. Unscrew the hub bearing nut, and a few bolts securing the ball joint.
4. Remove half shaft.
5. Remove the seal using an awl or screwdriver.

Why is oil leaking between gearbox and engine?

If oil flows or drips between the motor and the box, you need to find the defect as quickly as possible in order to eliminate it. If the defect occurred due to the fact that the crankshaft oil seal or the gearbox input shaft failed, then we can assume that you are lucky - then the repair will cost a minimum.

However, things can be much worse, because if ATF drips or flows between the engine and gearbox, this indicates a breakdown of the torque converter - then the car owner will have to fork out for repairs. It is worth noting that such problems are more common in Japanese or European-made cars, much less often in cars assembled overseas.

Gearbox oil leak

Attention! An untimely solution to the problem of oil leakage between the gearbox and the engine can lead to the complete failure of your gearbox.

Why does gearbox oil foam?

Even with the correct operation of all vehicle components, ATF can foam. This defect will not bring big problems to the car owner, but any driver in order to fix the problem must know why this is happening. Often, the transmission fluid foams in the automatic transmission for several reasons, due to incorrect ATF levels or a mismatch between oil manufacturers.

• As for the liquid level, an increased or decreased level (compared to the mark on the dipstick) is the most common reason that the liquid foams. If you have filled in too much ATF, it is advisable to immediately drain the excess. This is especially true for owners of German cars - Audi, Mercedes, BMW, Volkswagen - these cars are most sensitive to problems with automatic transmission oil. A low level is usually due to a leak, which may be due to the unsuitability of the gasket - replacing it will help solve the problem.
• As for oil producers. It is strongly not recommended to add oil from a new manufacturer to the box of your car if the old one remains in it. Otherwise, the foamed oil in the checkpoint is provided to you. If you decide to switch to a fluid from another manufacturer, then before changing the oil, the box must be washed from the remnants of the old transmission fluid.

Draining fluid from automatic transmission

Why is there noise in the checkpoint?

As practice shows, the noise coming from the gearbox can appear when the car is moving both in neutral gear and at speed, and in both cases the noise can be different. One way or another, the noise in the gearbox indicates a malfunction of the box.

• If the box starts to make noise while driving at neutral speed, then this is due either to a malfunction of the input shaft bearing, or to a low level of ATF in the gearbox.
• If the noise appears in a certain gear (usually starting from the third), then this indicates a failure of the blocking component or the synchronizer clutch.
• Also, noise can appear when the threads of your gearbox are loosened.
• Do not forget about the level of ATF - its lack in some cases also provokes third-party noise.

Gear box

Important! incomplete depressing of the clutch pedal also leads to noise or rattle in the box.

Which is better for eliminating noise: additive or oil?

Some drivers, having heard a noise in the gearbox, do not go to a specialist at the station, but to an auto shop to buy special additives.

You need to understand that adding additives to ATF (be it an engine or gearbox) will actually help eliminate noise for a while, but the additive can also negatively affect the condition of your gearbox or engine as a whole. If high-quality ATF is flooded, then there is definitely an additive in it. Moreover, its level is properly balanced, and adding a new component to the box can upset this balance. If, by adding an additive, the transmission fluid loses some of its properties, this is only half the trouble. It is much worse if the lubrication system of the motor or gearbox becomes clogged due to the additive.

It is better not to experiment, but to fill the box with only the ATF that the manufacturer advises, and refrain from using additives.

Video "Renault Symbol Gearbox Repair"

In this video you will learn how to repair the gearbox in a Renault Symbol car.

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