How Much To Fix A Transmission: Everything You Need To Know About

A transmission fluid leak is a failure that requires immediate attention, not paying attention to it can lead to serious problems, the causes are diverse, we will address the most common ones, the costs of repairing them and how to solve them with the experience of an expert in transmission leak repair.

Automatic transmissions can present problems of different kinds, but preventing these leaks from persisting will contribute to significantly minimize the failures of this essential component of the automobile.

transmission fluid leak

6 Causes of transmission fluid leaks

1. Drain plug

One of the most common causes of transmission fluid leaks occurs when the transmission fluid drain plug or bolt is not tightened properly, and traces of transmission fluid can be observed around the bolt.

In a great variety of models this bolt has a copper or bronze gasket which breaks down due to different causes. such as excessive pressure when tightening it, blows caused by stones and other objects while the car is driving on the roads, when this gasket is deformed it also becomes a cause for the leakage of the transmission fluid.

Car mechanic drain automatic transmission fluid
Car mechanic drain automatic transmission fluid.

2. Problems with the transmission pan or crankcase and pan gasket

The transmission crankcase is a piece that is placed under the transmission, on it the fluid is deposited when the car is at rest. in other words. it serves as a container for this fluid.

This tray is held by a series of screws and has a gasket generally made of cork. between it and the transmission housing. If fluid leaks are observed through these screws, as in the previous figure, it may be that they are poorly adjusted. or even isolated, and it may also be that the gasket is worn out.

When the screws that hold this tray are overtightened, the gasket may be damaged, since the cork is compressed and does not perform the sealing function, causing the fluid leakage to occur anywhere on this gasket.

Expert Tip: Another reason for the leakage of fluid through this crankcase is due to blows that it may suffer when the vehicle falls into potholes or is hit by rocks or other materials that may be found on the road while driving.

When receiving blows, the dents that are formed in the cover. decrease the storage capacity of the fluid, causing a greater pressure of this one on the most feasible places to escape, in addition the deformations in this cover, influence in the correct form in which this one must fit in the casing of the transmission, and of this form it affects the hermetic sealing that must exist so that the fluid is maintained properly inside the transmission.

There are poor quality gaskets. this is one of the cases of this failure. they deform with the adjustment of the bolts. or with the temperature. even being new. when it is required to change this gasket it is better to invest a little more in a quality spare part in the long run it will bring more benefit

Another cause for this gasket to deteriorate is an incorrect assembly, not aligning it properly causes it to deteriorate quickly, and it will not provide proper functionality, and the other cause of damage to this gasket is the time of use, the material it is made of, with time and constant temperature it loses properties and compresses or breaks, causing the inevitable leakage of transmission fluid.

3. The seals are broken

Two rubber transmission seals
Two rubber transmission seals.

A transmission has several types of seals to maintain adequate hydraulic pressure, these are manufactured with a type of material that has elastic properties, that can withstand movement, that stretches easily and that has the ability to adapt to the operation of a transmission avoiding fluid leakage.

The fluid level of a transmission is very important in its operation, and this level depends largely on the good condition and operation of the seals.

If any of them, or several are broken, or have been deformed, there will be a fluid leak in the transmission, affecting all its operation, valves. 0- rings. solenoid flow control, pressure distribution with the torque converter, grip of belts and discs, absolutely everything inside the transmission will be affected if the fluid level decreases.

These leaks are noticed in several ways, the first thing is to measure it correctly, and it must be done with the engine running, the gearbox warm and the gearshift in N or P. if you notice a low level, it is a clear sign of alarm and that the problem must be solved promptly, since the transmission fluid does not wear out. if it is missing, there is obviously a leak.

Expert Tip: Another way to notice the leak is to look at the floor where the vehicle is parked, if there is leakage of this fluid, you will notice stains on the floor.

Transmission seals have a useful life, as it is natural they tend to wear out and crack, they dry out eliminating their compacting quality, this causes fluid leaks, establishing which seal is causing the leak is a task for specialists in the field of transmission mechanics, as eventually the transmission must be disassembled, there are seals on the output shaft, input shaft, drive shaft lever box. tail box. speedometer input and valve body.

Failure to fix this failure in time can lead to more serious and costly problems in the transmission.

4. Leakage at the speedometer connection

This connection in the gearbox has a gasket that when it loses elasticity and dries out it lets the fluid pass through, damaging other components such as the cluster, and putting the transmission at risk due to the low fluid level. If the speedometer linkage pinion has lost its shape, the incorrect way of moving damages the seal and creates spaces for fluid leakage to occur.

It can also occur due to excess fluid in the transmission.

5. Torque or torque converter leakage

Automatic transmission with torque converter
Automatic transmission with torque converter.

It is responsible for managing the amount of fluid with which the automatic transmission must work, and thanks to it. the engine transfers its force to the transmission gears without abruptness.

A malfunction of the converter will cause malfunctions in the operation of the car. which will be reflected, among other signs, in the slipping of the gearbox and sudden tremors in the running of the vehicle.

The deterioration of the torque converter seals causes the leakage of the transmission fluid, causing a loss of pressure inside it. so it slips and overheats, the bearings of this converter suffer wear due to use. becoming another cause of fluid loss.

A converter can also suffer cracks and breakage for various reasons, causing fluid loss, these problems in this essential component of the transmission, also requires review by skilled labor, since for diagnosis it must be disassembled, which involves uncoupling the gearbox from the engine.

6. Leaks in the fluid supply and cooling lines

These lines or pipes are in charge of transporting the transmission fluid to cool it. since at high temperature it loses lubrication properties and pressure, after cooling it is taken back to the interior of the gearbox, it happens that these pipes can suffer failures due to rust corrosion, blows, such as dents or breaks, or exposure to high temperatures, being able to form small holes that are sources of fluid leakage.

In the manufacture of these fluid lines of a transmission, steel or aluminum is used, and they have an acceptable durability, but they are not exempt from cracking or breaking completely.

On the other hand, there are feed lines that have a part in rubber hoses, these can break or crack due to dryness.

Cost of repair

Transmission leak repair costs depend on several aspects, including the cause of the leak, the different parts suppliers and the different rates of labor specialists for this type of repair.

An occasional leak can be solved with special additives for these cases, which act on the seals making them more sensitive, to make them expand, with its special plasticizers the seal is soaked to fit the surface and stop the leakage of fluid.

Although they do not work if the seals are broken, only serve for minor leaks, prolonging the functionality of a seal or the joints where the leak is generated the cost of this type of additive is $25 and $35. without requiring labor because they work by emptying the contents of the container into the transmission as if it were emptying the transmission fluid.

In the cases of leaks due to cracks and fissures of smaller dimensions there are products in the form of putties that serve to perform cold welding, these have costs between $20 and $30. but they require a specialist since these cases require working on the physical part of the transmission, and depending on the place of the repair it can take up to a day. which would mean a cost for labor close to $100.

A car mechanic repairing automatic transmission
A car mechanic repairing automatic transmission.

The transmission leak repair without having to disassemble the transmission, may include changing the drain plug in the case of transmissions that have it, is in the order of $5. without labor, this is a job that has no further complication than to recover the fluid and recycle or replace it. if it is done by a mechanic should add an estimated $8 to $12. which is what it can cost an hour of work.

If a pan gasket replacement is required, we would be talking about a figure between $10 and $40, which is the price of a crankcase kit depending on the model of the car, plus an average of $20 to $28 for labor.

In the case of pan replacement, this ranges from $30 to $45. plus $20 to $28 for labor.

If the fluid leak is caused at the torque, this kit has a cost for the full torque of $150 and labor of $80 to $120. in the extreme cases of replacing the torque the cost is between $80 to $100. plus labor between $100 and $130.

A leak from the speedometer line connection with labor and replacement of the line costs between $38 and $43.

Leaks caused by supply and cooling lines $40 and $60. plus labor in the range of $80.

Typical transmission leak repair costs for the various types of seals are higher, requiring disassembly of the transmission, which is equivalent to several days of work, taking into account that a transmission master kit exceeds $150 and more than $300 for labor we could say that this cause of fluid leakage is costly to repair.

In all cases of leakage, you must add the replacement of the transmission fluid, taking into account that the cost per liter depending on the make and model of the vehicle is between $7 and $10.

How to fix it

The way to solve transmission fluid leaks efficiently is through an inspection and analysis of a specialist in automatic transmissions of the vehicle model you own. these professionals have the right tools, and have the experience of other cases, allowing them to easily reach the cause of the leak.

Once this professional identifies and performs the necessary tests, he or she provides the diagnosis that includes the parts to be replaced and the possible costs of these and of the qualified labor for the transmission leak repair.

A new oil filter was installed in the automatic transmission.
A new oil filter was installed in the automatic transmission.

Although easy to detect leaks, such as the drain bolt and pan gasket, may lead you to believe that you can solve it yourself, it is advisable to have a professional guide you. since the transmission of your car is an indispensable component that needs a correct repair and maintenance, a bad assembly of a gasket can damage other components of the transmission and cause the damage to intensify and this will result in more costs.

Prevention is another way to solve problems of this nature, receiving recommendations on how to drive automatic transmission vehicles can save many problems, and can mean saving money on repairs, these boxes bring the neutral to use it, stop at a traffic light without placing the gearbox in N is forcing the transmission, the same happens when not making manual changes in mountainous roads with steep climbs, this means that driving properly, will provide a longer life to your transmission and that will reflect positively on your economy.

How serious is a transmission leak?

Transmission fluid leaks, if not attended in time, generate severe damage to the transmission, low fluid levels cause high temperatures, this causes the fluid to lose its lubricating properties and significantly decrease the effects that make them generate the necessary pressure for the proper functioning of discs and gears inside the transmission.

A leak causes changes in the characteristics of the gaskets and seals, hardening them and making them lose their flexibility. A transmission fluid leak that is poorly attended or neglected will cause repairs that can cost thousands of dollars.

Can you drive with a transmission fluid leak?

Before starting a vehicle, a good driver should make certain checks, the level of coolant, brake fluid, engine oil and transmission fluid, with the latter, if you notice that the level is not adequate you should take the car to the specialist promptly.

You can drive it a few kilometers, but the essential thing is to take care of the leak immediately, while driving the car with transmission fluid leaks, the car will drain more fluid, there is a risk that the transmission will run out of fluid completely or with so little that the damage will cause the total collapse of the transmission.

Shifting will become more complicated, and overheating due to lack of fluid will eventually ruin critical transmission components, resulting in high repair costs.

An automatic transmission with scarce fluid is prone to overheat, this fluid is responsible for the essential lubrication of all transmission components, its good level and condition depends on the functionality of the valve body, the perfect tightness of o- rings, the flow control exercised by the solenoid, the perfect grip of discs and belts.

The overheating of this fluid prevents it from performing such functions due to the loss of properties at high temperature, causing, among other causes, the slipping of the gears, which may cause unexpected accidents due to the lack of control of the vehicle.

A transmission fluid leak is highly flammable and can cause serious explosions, endangering the lives of the vehicle’s occupants and other people in the vicinity of the vehicle.

The legislation of many countries are strict in regulating the circulation of vehicles with leaking transmission fluid, and this is motivated by ecological reasons, because apart from the risks we have exposed, there is also the risk of environmental pollution, since they are non-biodegradable substances.

Can transmission leak be fixed?

A new oil filter was installed in the automatic transmission.
A new oil filter was installed in the automatic transmission.

Have you ever noticed your transmission leak at any time? How can it be fixed? How much does it cost to fix this matter at hand? So on this article you will about to learn some of the things you need to know in case your transmission leaks and also some computations on as to how much will it cost you to fix it.

First thing’s first, the answer to that question is YES. Yes transmission leaks can be fixed. The fact that it can be fixed depends on where part is leaking. In short, the cost will also depend on its parts.

If you notice that there are some fluid leaking from your vehicle or motorcycle, sure it is a transmission leakage. The best thing for you to do is to identify what part is leaking, then do necessary things to stop its leakage. Doing so will prevent the vehicle from facing more serious problems and preventing you to spend a lot of money for that one.

If you can do it by yourself and with the materials needed are at hand then you might not be spending much. But if you will call out for someone to fix it, then you should probably be preparing at least 50 dollars or more, depending on the problem, in order to fix this problem.


Definitely, a transmission fluid leakage due to the causes we have mentioned and others, such as damage caused to these parts by accidents, will inevitably cause serious mechanical damage to the car and economic damage to your pocket.

You should take care of it in time and avoid driving the vehicle when it presents these leaks, for your own safety, for the vehicle’s safety and for the environment’s sake.

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About Matthew Webb

Hi, I am Matthew! I am a dedicated car nerd! During the day, I am a journalist, at night I enjoy working on my 2 project cars. I have been a car nerd all my life, and am excited to share my knowledge with you!