Rear Main Seal Replacement Cost

Rear Main Seal Replacement Cost – How Much Is It?

So, imagine that you’ve just noticed a big puddle of oil on the ground in your garage and you are almost sure that your rear main seal is failing and has to be replaced. But what does the rear main seal replacement cost?

Although the rear main seal is a piece of rubber, it is a crucial part of your car and this seal is making sure that your crankshaft seals properly. This means that the seal will prevent fluid leaks and potentially hazardous situations on the engine.

The engine, to function properly, has to have working seals and gaskets. These components will prevent the fluids from escaping and will work to keep your engine healthy and properly lubricated.

Also, when you are experiencing some seal leak, it is a good idea to observe the oil levels inside of your engine. You never know from where it’s going to start leaking and will worsen the situation.

A good inspection of all the seals in your car is a must every 50,000 miles. This is to make sure that everything is in check and nothing is prone to failure.


In this article, we are going to learn a lot about the rear main seal. We will learn what this seal really is and where it’s located on the vehicle. We will also see why these rear main seals fail and how you can recognize a failing seal. Then, we are going to cover how this rear main seal is replaced and also the rear main seal replacement cost. So, let’s begin.

What Is A Rear Main Seal?

The rear main seal is a circular thick rubbery component that slides between the crankshaft and the engine block. This seal is working hard to keep your oil inside of the engine bay.

If your rear main seal starts to leak, you will start to lose a huge amount of oil from your car. If this passes by unnoticed, your engine will starve from oil and this will eventually cause your engine components to friction.

And this friction will damage your bearings and cylinder walls. These leaks will prevent the oil from reaching some integral engine components and could escalate to a bigger rear main seal replacement cost.

If you leave this problem unfixed and allow the oil to leak from the engine, it can cause a major catastrophic engine failure sooner or later. And you don’t want that.

Especially for a part that costs a few dollars at your local parts store. These rear main seals do not generally cost more than $25. But the rear main seal replacement cost is very expensive since it requires a lot of man-hours to be done. That’s especially in some cars that have a really tight space to work on and will bring a lot of hurdles for the mechanic to access them and replace the rear main seal properly.

If your rear main seal is leaking, a good OEM seal is a tight fit and this will guarantee that no oil escapes from your engine. Also, you have to be sure that this part is very soft and is basically a new part. You don’t want to get a new plasticky rear main seal that will not do its job properly. And the rear main replacement cost is not going to be very expensive.

Where It Is Located?

Transmission repair

The rear main seal, as its name implies, is a seal that makes sure that your crankshaft stays lubricated all the time and no oil leaks out from the engine.

The name is a clue that the seal is located in the rear. This is always the case if you have a rear-wheel-drive car. The rear main seal is right between your engine and transmission.

In front-wheel-drive cars, this seal is located on the right side of the engine bay. If you can find where your transmission is, you will easily find the rear main seal.

This is the case because, in front-wheel cars, the engine is oriented differently compared to a rear-wheel-drive car. This can also make the removal process of this rear main seal to be a lot more complex and it can be tricky to get a hold of it.

Tight engine bays make this repair a lot more expensive than you planned. So, the best way to avoid big repair bills is to find a car that has a lot of working space. Rear main seal replacement in older cars is a breeze. But if you try to replace one in an Audi, you will have to tear the whole car apart and pull the engine out. And this costs time and money. So, if you want to save some cash getting a car that is easy to work on, it’s worth considering.

That’s why I love big American muscle cars. They are simple to work on and extremely easy to repair. Just bolt the component off and replace it with a new one, it’s easy as that.

Why Does The Rear Main Seal Fail?

The rear main seal fails because of two factors. These factors are affecting its lifespan and make it unusable. One of these factors is heat and the other factor is age.

In the engine bay, there is a lot of heat that affects these rear main seals and ruins their sealing characteristics.

The other factor is age. It doesn’t matter the conditions in which that you are keeping your car. These parts, over time, become brittle and plasticky. When they harden, they tend to get looser and allow the oil to pass freely. Also, make sure that you don’t overfill your engine with motor oil.

Personally, my rear main seal failed because I have overfilled my car with motor oil. When I put the factory-recommended oil and in the right amount, it showed that the amount is too high.

So, I had to remove some of the oil from the car but I couldn’t visit a mechanic and I drove the car as it is. Driving under these conditions made the old and plasticky rear main seal fail and the underside of my car was splashed with oil. This was the case because my car is front-wheel-drive, and when the seal fails, it splashes the underside of the car.

I had to replace the rear main seal and it cost me around $400. This was the case because my car has a small engine and is extremely easy to access. The job lasted 5 hours and an experienced mechanic tackled this job perfectly.

So, make sure that you don’t overfill your car with engine oil. This is another factor that can increase your rear main seal replacement cost.

How To Recognize A Failing Rear Main Seal?

A leaking rear main seal is a big problem. And it’s not that hard to recognize if you have a real main seal failure. To do this, you need to know the location of this rear main seal. And this is behind the firewall of the vehicle. The seal is basically located between the rear of the engine and the flywheel. Then the flywheel is connected to the transmission.

So, to get to the flywheel and remove it, you will first need to remove the transmission, and then you will have to remove also the flywheel. Next, you will have access to the rear main seal.

But enough with mechanicals, let’s see first how you can spot that your leaky rear main seal and diagnose the issue. Because at the end of the day you have to be sure that it is the rear main seal that is leaking oil. You don’t want to pay a rear main seal replacement cost for nothing. So, let’s discuss the symptoms of a bad rear main seal.

Oil Stains On The Ground

Oil stains on the ground will be a normal thing if you are having a leaky rear main seal. And these stains will be puddles of oil after a while if you don’t get this thing sorted out.

But you should be aware that the oil can leak from numerous places. Maybe you have a leaky oil pan, or your oil pan gasket has failed. That’s why you need to figure out the location of this leak. The location should be from the back of the engine.

To make sure about where your leaks come from, it is a good idea to park the car in the same spot for some time.

Make sure that the car is parked in the same spot. If the leaks come from the oil pan, then the leak should be further at the front of the car. If the oil stain is caused by a rear main seal, then the oil stain should be right on the firewall mark.

So, to be 100% sure you have to check the car from underneath. If you have some jacks, you can secure the car and lift it in the air. By accessing the car from the ground, you are going to have a clear vision of where the oil is coming from. If there is a big splash of oil under the bell housing, that means that you are in big trouble as this rear main seal has to be replaced and you need to google “rear main seal replacement cost”. That is something that we are going to discuss later.

Oil Loss

Another symptom of a rear main seal that is leaking is big oil loss. Especially if the seal is leaking, the loss of oil is going to be more and more pronounced.

Your oil will simply disappear and you will have to refill your oil daily in some extreme cases. That’s why you need to check your oil level frequently.

Imagine that your rear main seal has failed and you are simply not aware of this situation. You drive the car for a thousand miles and you don’t pay attention. Suddenly, the engine stops and doesn’t turn on.

This means that your engine is done. In this case, you are going to need a completely new replacement engine that will cost thousands of dollars.

So, when you are experiencing some leaks on the ground, make sure that your oil level is in check. By observing the oil level frequently, you will know that you are losing oil and you will refill the oil on time so that your engine will not be starved from oil that will result in catastrophic engine damage.

When You Should Replace This Seal?

Rear Main Seal Replacement Cost

This is a good question, mainly because if you don’t have enough cash in your bank account you can continue driving like this. When this seal starts to fail small drops of oil start to appear and you need to be aware that you are having a rear main seal leak on your car.

By knowing this, you will be sure that you are not going to be left without oil at any moment. After you acknowledge that your seal is leaking always have an oil bottle inside of your trunk for refills.

But as time goes by, this problem exacerbates and the leaks become puddles. Things are starting to get serious. By serious, I mean that you cannot handle the leaks anymore and refill the oil. Your car is losing too much oil from the rear main seal. This requires a rear main seal replacement. The replacement rear main seal is cheap, but the rear main seal replacement cost is expensive. This seal can cost you a lot of money to replace. And that is something that we are going to cover in one of our next chapters.

How To Replace A Rear Main Seal?

Replacing a rear main seal is not a simple task. To do this job, you need to have a proper working environment because you need to access the car from underneath if the vehicle is a rear-wheel drive. This is because the transmission, torque converter, and flywheel have to come off to reach the rear main seal. And that’s a lot of work to be invested into this job. That’s why the rear main seal replacement cost is that expensive. But we are going to cover that later. Now let’s see how we can replace the rear main seal in a DIY fashion.

To do this job, you are going to need wrenches, a lift, a jack for the transmission, and a new rear main seal.

Step 1

The first step involves jacking the car up into the air and inspect the leaks. The next thing to do is to start unbolting the transmission of your vehicle.

Step 2

Make sure that you have the right support that is going to handle the transmission and you will not end up hurting yourself. That’s why this is a two-man job. You will need to get a transmission jack to attach the transmission to it and slowly bring it to the ground.

Step 3

After you removed the transmission, now it’s time to remove the torque converter. The torque converter should pop out easily.

Step 4

The next step is to remove the flywheel. The flywheel is usually held by a couple of bolts and will be a little bit tricky to pop it loose. A few taps with the hammer will do the trick and will release the flywheel.

Step 5

Now it’s time to remove the rear main seal cover. This cover is usually held by a few bolts. After you remove the cover, you can reach the rear main seal.

Step 6

Now it’s time to address the rear main seal. This rear main seal is a pain to remove. You will probably need a screwdriver to pop it loose. Just make sure that you don’t damage the metal around it. It may be tricky but it will get loose after some persuasion.

Step 6

After you removed the old seal, you can inspect it and you will see that is hard as a rock. That’s why the seal was leaking. Replace the old seal with a new one. Make sure that it fits nicely and try not to damage it while you are replacing it. Then you are ready to reassemble everything and make sure that you don’t end up with leftover parts after you are done with the job.

This is a tough and demanding job. But if you are willing to do it and if you have the tools, nothing can stop you from doing it. Wrenching on your car will probably be your favorite sport. Now let’s discuss the rear main seal replacement cost.

Rear Main Seal Replacement Cost

Now we came to the main topic and that is the main seal replacement cost. The rear main seal replacement cost is not cheap, to be honest. The part is not that expensive at all, and you can find a rear main seal for $25 or less in some situations.

What makes this job expensive is the labor. This job is highly demanding in labor and will require a lot of man-hours to get things done and sorted out as they should.

It usually takes between 6 to 10 hours to get things straight and in proper working order. This is a lot of time that you have to invest to get this work done.

Or if you take your car to a mechanics shop you cannot expect that it’s going to cost you less than $1000. This is the case because most repair shops have rates of $50 to $100 per hour. This is not cheap by any means.

Also, your car will be at the shop for a few days, since mechanics also work on other customer’s cars. Patience is another aspect of this job; you have to be patient and make sure that you have another vehicle to drive while this car is serviced.

How To Save Money On This Seal

If you want to save money, you can do this job at a friend’s house. Supposing that he has a lift or jack stands, you can pay him a lot less money to get this thing done. Or you can do this job together as a team.

You will be able to work on your car and also hang out as friends. Grab a beer or two and enjoy your day. Because that’s why friends are here for. To help us when we need help and also to help them when they need help.

Can I Drive My Car Like This?

As we said, you can keep driving your car as it is but you shouldn’t. This is the case because your car is constantly losing oil and if you don’t fill the car with oil, you are going to leave your engine dry and your engine is going to fail.

That’s why you should check your oil level very often and make sure that every time it has the right amount of oil inside and everything is properly lubricated.

Rear Main Seal Replacement Cost – Conclusion

In this article, we have covered a lot when it comes to rear main seals. We learned what are they and what their purpose is within your car. We’ve also learned about where they are located inside of the engine bay, and how to find out if you have a rear main seal leak.

Then we have covered how to replace a rear main seal on your car. This may come in handy if you want to do some DIY work on your car. And we finally covered the rear main seal replacement cost. This is important because this work is not cheap and can cost a lot of money to complete, mainly due to the complexity.

And finally, we found out how you can save some money by performing this replacement job at your house or a friend’s house. That’s if your friend has the proper tooling.

Approved Tools

These tools have been tried and tested by our team, they are ideal for fixing your car at home.

Leave a Reply

Your email address will not be published.