When to change transmission fluid

8 minute read Published on Apr 20, 2024 by BrokerLink Communications

Cross-section of a car gearbox and clutch.

Changing the fluid inside your car is crucial when it comes to preventing a bad transmission. In fact, if you want to avoid car engine damage altogether, making sure that the fluid levels are where they should be is extremely important. Continue reading to learn more about what transmission fluid does and when to change it.

What is transmission fluid?

Transmission fluid is one of the many types of fluids that your car relies on to function as it should. It is like lotion for your transmission. Just like how your vehicle needs power steering fluid or regular oil changes, it also requires transmission fluid. Transmission fluid is primarily used as a lubricant to lubricate the bearings and metal parts that are located inside the transmission gearbox. In essence, transmission fluid decreases friction, preventing the metal components from grinding against one another, which is a main cause of wear and tear and can even lead to an engine breakdown.

Given the important role that transmissions play in a car, making sure that it’s functioning correctly is a crucial job, and that’s the job of the transmission fluid. For those who don’t know, a car transmission is a gearbox that consists of multiple gear sets and gear trains. It is the part of the car through which the driver controls how much power is exerted. Thus, many people think of a car transmission as the main control system of the vehicle. This is the case no matter what type of car transmission is in your vehicle. The three main types of car transmissions used today are manual transmissions, automatic transmissions, and continuously variable transmissions (CVT).

Please note that despite the different ways that each type of transmission functions, all of them require transmission fluid. That said, the transmission type in your car will determine what type of fluid is needed. For example, there is an automatic transmission fluid for automatic transmissions, a manual transmission fluid for manual transmissions, and so forth. Thus, it is important to pay attention to the type of transmission fluid you are putting in your car each time you change it - especially if you plan on changing or topping up the fluid on your own.

What is the purpose of transmission fluid?

As mentioned, transmission fluid is a lubricant that is used to reduce friction between the various metal components in a car’s transmission. Without this type of fluid, or when there isn’t enough of this type of fluid in your car, it can cause or exacerbate a wide range of issues. Namely, you are speeding up how quickly your car will wear out, which will shorten its lifespan and lead to other issues down the road. For example, if you want good fuel economy for your car, maintaining it properly is crucial. A key part of car maintenance for road trips or even just during the changing seasons is to change and top up your transmission fluid regularly.

When to change your manual or automatic transmission fluid

The interval for changing the transmission fluid in your car depends on a number of factors. While there are general recommendations, you should always refer to your owner’s manual, as one of the biggest factors that determine how frequently you should change your transmission fluid is the type of car you drive. Every automaker will include an estimated change interval in the owner’s manual for each model of vehicle they produce.

Beyond the type of vehicle, you drive, a few other factors that can influence the fluid change frequency are how you drive, how frequently you drive your car, where you drive, e.g. what types of roads you drive on and the types of weather conditions you drive in, as well as the type of transmission your car has.

Thus, if you want advice on how often to change the transmission fluid in your car, you could also ask a licensed mechanic for their professional opinion.

That said, generally speaking, most auto experts recommend changing the fluid in your car every 50,000 to 100,000 kilometres. Sometimes, this is also written as years, with an estimated every two years, though it depends on your annual mileage. Typically, manual transmissions require fluid changes more often than automatic transmissions. Thus, the recommended change interval for manual transmissions is every 50,000 to 90,000 kilometres, though in some cars, it could be as low as every 25,000 kilometres.

Signs of low transmission fluid

If you aren’t sure whether your car is due for a transmission fluid change, look for some of the telltale signs that your transmission fluid is low. They are as follows:

There is a noticeable delay when shifting gears

If your car is low on transmission fluid, this means that there may not be enough pressure to shift gears quickly or with ease. This means that it might take noticeably longer when shifting from a gear-like drive into reverse. It could take several seconds to shift gears. Oppositely, another sign that you might be low on transmission fluid is if your vehicle shifts gear faster than usual. You may also notice that the process of shifting gears is less smooth than normal.

In essence, if shifting gears feels jerky or if you notice that the gears are shifting faster or slower than normal, it could mean that you need to change your transmission fluid.

Your car slips out of gear

A second symptom of low transmission fluid is when you switch gears, but your car slips back out of gear. This is a telltale sign that your car needs more transmission fluid. A transmission that shifts spontaneously or erratically is a bad sign and could even mean that a lack of fluid has led to more serious problems.

You are unable to shift gears in your car

Third, if you are unable to shift gears in your car, then it’s possible that your vehicle is completely out of transmission fluid. This fluid is required to switch gears, so if nothing happens when you try to switch gears, it could mean that there is no fluid left. This is a major problem and can cause serious damage if not rectified immediately. In fact, if left untreated, it could lead to permanent transmission failure. For those who don’t know, major repairs for transmissions are costly as is replacing a car transmission. Generally speaking, anytime something needs to be fixed in your vehicle, whether you need to fix the AC or repair your car radiator, take care of it as soon as possible.

Your transmission overheats

Your transmission overheating is one final sign of a lack of transmission fluid. If things get so bad that your transmission overheats, then chances are you were extremely low or completely out of transmission fluid. A clear sign of an overheated transmission is when you see smoke coming from the hood of your car or smell a burning odour coming from your car. If you notice this, immediately turn off your car and call a mechanic to have it evaluated.

How to change the transmission fluid in your car

If you’ve decided that it’s time to change the transmission fluid in your car, you have two choices: do it yourself or hire a mechanic to do it for you. Depending on your comfort level and your familiarity with cars, you will likely know which is the right decision for you.

Typically, most people choose to take their cars into auto body shops for regular checkups, and a fluid top-up should be a part of this, along with replacing your car air filter and doing an oil change. Thus, if your car is due for an annual checkup soon, then it might be worth waiting until then to change the transmission fluid if you can afford to do so.

Remember, if you notice any of the telltale signs of low transmission fluid, it’s best to take action as soon as possible.

However, if you choose to change the transmission fluid in your car, be sure to do your research in advance and consult your owner’s manual. For a brief overview of how to change transmission fluid, keep reading.

A step-by-step guide to changing the transmission fluid in your car

Learn how to change your car’s transmission fluid in a few easy steps:

1. Turn your car on and let it idle

First, turn on your vehicle and let it idle for a few minutes. Most of the time, automakers recommend that you change your transmission fluid once your engine is warm. Once your car has been running for a few minutes, turn off the ignition, raise your car using either a jack or on ramps and make sure your car is in a secure position.

2. Position a catch pan and remove the bolt

Step number two is to position a catch pan. We recommend a minimum of two gallons before slowly removing the bolts from one side of the transmission pan. Once the pan is in a position where it can tilt and drain, you can remove the rest of the bolts to lower the pan and then remove the remaining fluid into the catch pan.

3. Remove the transmission filter and O-ring and install the new filter

The next step is to remove the transmission filter and O-ring. Since the filter contains transmission fluid, make sure that the drain pan is underneath you as you do this. Once removed, you can then install the new transmission filter, making sure that the O-ring is in the right place.

4. Attach the gasket to the pan and screw in the fasteners

Step number four is to attach a new gasket to the drain pan. Be sure to do this with oil-soluble grease rather than a gasket sealer or adhesive. After that’s done, screw in the fasteners and torque the pan bolts.

5. Lower your car and fill the transmissions with fluid

The final step is to lower your car and fill the transmission with the amount of fluid that your automaker recommends. There should be a transmission fluid dipstick that you can use to check that you have the right amount of fluid in your car. Once this step is complete, close the hood of your car and check your engine for any leaks.

Contact BrokerLink

Reach out to BrokerLink today to find out more about what transmission fluid does and how it works. As automotive experts, we can also answer questions about how long oil changes take and how AC works in a car.

Plus, as car insurance professionals, we can give you advice on the best type of coverage for your needs. We can even give you tips on how to save money on auto insurance, such as by driving a fuel-efficient car, such as a hybrid or electric vehicle.

Get in touch with BrokerLink today to request a free auto insurance quote!

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