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Topping up on oil, gasoline, and antifreeze is an important part of maintaining and running a vehicle. But transmission fluid is another matter. Because it’s part of a closed system, the fluid levels usually only go down when there’s a leak somewhere. These days, the transmission fluid in the system is meant to last the vehicle’s lifespan. That’s why many manufacturers are opting to seal off access to transmission fluid altogether, leading to a so-called sealed transmission.

Sealed Transmission Explained

Sealed transmissions are, as their name implies, sealed off completely with no easy way to get to the fluid inside.  Other than this fact, they act much like usual transmission systems, which help adjust gears and manipulate power from the engine. The fluid inside a sealed transmission is advertised to last the transmission’s lifetime, meaning no maintenance or fluid change should be needed to a certain extent. However, do note that when the transmission fluid goes bad, the entire transmission system is more likely to fail. So while the marketing isn’t false, it can easily be misconstrued.

It’s easy to tell if you have a sealed transmission in your vehicle once you check under the hood. You’ll notice a distinct lack of a transmission dipstick anywhere in the engine bay. The dipstick handle is usually red and easy to spot.

Benefits and Drawbacks of a Sealed Transmission

Sealed transmissions have advantages and disadvantages you should keep in mind, especially when you’re comparing them to traditional unsealed transmissions.


One of the main benefits of a sealed transmission is that vehicle maintenance becomes easier.  Because the sealed transmission can last the vehicle’s lifetime, it can cut down your list of maintenance tasks. While traditional unsealed transmissions require transmission fluid changes every 50,000 to 60,000 miles, sealed transmissions won’t really need to be touched unless you start noticing signs of a bad transmission.

In addition, because regular checks and flushes aren’t needed for sealed transmissions, you’ll be able to reduce the amount of transmission fluid being dumped in landfills.


While sealed transmissions are marketed to last the vehicle’s lifetime, it’s not wholly unheard of for them to still need maintenance and repairs. A lot of it has to do with the conditions the transmission is put through. Many experts have noted that if the vehicle is used for off-road driving or towing, the fluid in its sealed transmission might need checking after 50,000 miles. The same goes for a vehicle that drives through particularly dusty conditions.

The amount of stress placed on the transmission is what will determine whether it needs to be checked and maintained. One of the main drawbacks then becomes the fact that you can’t check the condition of your transmission fluid yourself because of the seal. You likely won’t notice any problems with the transmission fluid until problems start arising. It’s also much more difficult to repair.

Sealed Transmission Maintenance and Repair

At this point you might be wondering, “Can a sealed transmission be serviced?” In short, yes. Maintaining and repairing a vehicle’s sealed transmission is possible, but it’s the sort of project even experienced hobbyists might need expert help for. There’s a set process that needs to be followed which includes raising the vehicle up on a lift. If you notice problems while switching gears in your vehicle, it’s best to have a licensed mechanic check the fluid in your sealed transmission.

Once they fix whatever’s wrong, the mechanic can even do a sealed transmission fluid change if needed. If you’re particularly worried about your vehicle’s transmission fluid levels due to, say, high mileage, you can always pay for a fluid flush and change regardless. When it comes to transmission, it’s better to be safe rather than sorry.

While car manufacturers might advertise the sealed transmission as a lifetime part, remember that the definition of “lifetime” can vary. You might still need repairs and maintenance down the road, which can be inconvenient because sealed transmissions are much more difficult to repair. Having them checked periodically won’t hurt in the long run.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

File Under : Transmission , DIY
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