Automatic Transmission Fluid

What is a transmission?

transmission repairs

If your vehicle is powered by gasoline or diesel, your engine has an issue: it can only spin at a narrow range of speeds, but your vehicle needs to travel at a wide range of speeds! Obviously, connecting the engine directly to the wheels just wouldn’t work. This problem is solved with the use of a transmission.

The transmission allows your engine to stay at the right speed (or RPM) over a wide range of road speeds; traditionally through the use of gears. Some vehicles now also use completely gearless continuously variable (CVT) transmissions as well.

Basically, the transmission takes the rotational torque from your engine, and helps turn it into the force that moves your vehicle. If your transmission stops working, your vehicle stops moving!

What is transmission fluid?

Every transmission is partially filled with a special automatic transmission fluid, or ATF. This fluid’s primary function is to lubricate the hundreds of internal parts, but it’s not done there! One of the hardest-working automotive fluids, transmission fluid has a lot of other jobs to do, including cooling the transmission; helping the internal clutches to grip just the right amount; and acting as the hydraulic fluid that applies and moves different parts. Without its fluid, your transmission is about as useful as your body would be without blood!

Why does my transmission fluid need to be changed?

transmission slipping
This transmission has been neglected too long. The fluid is almost black; the filter is plugged with clutch material; and all the metal debris in the pan indicates a looming internal failure.

Transmission fluid contains a complex blend of additives that allows it to perform all of its different jobs, while protecting the transmission from wear. These include anti-wear additives; rust and corrosion inhibitors; detergents; dispersants and surfactants (which protect and clean metal surfaces); viscosity index improvers and modifiers; seal swell additives (to condition seals and prevent leaks); anti-foam additives and anti-oxidation compounds; cold-flow improvers, high-temperature thickeners; gasket conditioners; pour point depressants; and friction modifiers.

Over time, all of these additives eventually wear out and lose their ability to do their jobs; and that’s when transmission wear really starts to take place. Regularly replacing your aged transmission fluid with new fluid is the single most important thing you can do extend the life of your transmission, which is usually the second-most expensive component on your vehicle.

How often does my transmission fluid need to be changed?

Some customers believe they can wait until their transmission fluid looks bad before changing it. That’s a mistake. Because of all the aformentioned additives in today’s fluids, transmission fluid needs to be changed based on mileage more than condition. Transmission fluid that is dark brown or black usually indicates a lot of internal wear, or even a pending failure, and changing the fluid at this point is usually too late. A transmission flush or fluid change will never repair a transmission problem; it’s meant to prevent transmission problems when done on time.

We usually recommend replacing your transmission fluid (and filter, if equipped) at the service interval recommended by your vehicle’s manufacturer. This interval can be found in your owner’s manual, or we can look it up for you! Most modern vehicles require a transmission service every 80,000 – 160,000 km.

Occasionally we may recommend a transmission service earlier than the manufacturer recommends, based on our experience in the industry. A good example of this would include vehicles with “lifetime” transmission fluid – where “lifetime” often turns out to mean the life of the transmission, not the vehicle!

Transmission service vs transmission flush:

transmission flush
The transmission pan removed, showing the metal filter inside.

A lot of other Airdrie automotive shops are selling a transmission flush, while we only perform a transmission service. What’s the difference?

A transmission flush involves using a machine to introduce new fluid into your transmission, while drawing the old fluid out. This service is quick and easy; a very profitable service for shops that sell them. This convenience comes with a cost, though: a transmission flush often doesn’t provide the full service that your transmission requires.

A transmission service involves a lot more work than a flush. In addition to replacing the fluid, this service also includes replacement of your transmission filter, if equipped. Your transmission filter is usually accessed by removing a pan or cover on the bottom of your transmission. While we’re inside there, we also clean the inside of the pan, including special magnets that are installed to trap metal filings and debris. Some transmissions also require certain adjustments while the pan is removed. Checking your vehicle’s transmission control module (transmission computer) for software updates, and installing them if required, completes our full and correct service of your transmission.

“Multi-vehicle” transmission fluids: Run away!

airdrie transmission
We stock over 25 different transmission fluids, in order to service your vehicle properly.

Some businesses, including most quick-lube shops, are using a multi-vehicle or universal transmission fluid when servicing your transmission. This might have worked 20 years ago, but today it’s a big “no-no”, because transmission fluids have become very specialized and unique. Fluids are different enough now that it’s absolutely impossible for one fluid to meet the specific requirements of one manufacturer, while also meeting those of another.

The difference between “recommended for” and “approved for”: The makers of these universal fluids often provide a long list of vehicles that they have recommended their fluid for, but these fluids often never have any actual OEM approvals. An OEM approval means that the fluid has been tested by the automaker, and is certified to actually meet their requirements.

Using a universal transmission fluid often shortens the life of your transmission at best, and can cause a total failure of the unit at worst. As one example, we’ve serviced several Honda Civics that came to us with a slipping transmission after having Castrol multi-vehicle ATF installed at a local lube shop; all of which were completely fixed by re-installing the correct Honda DW-1 transmission fluid.

Transmission leaks:

transmission leak

Most transmission fluids are dyed a red colour. If you have something red dripping under your vehicle, there’s a good chance it’s a transmission leak. (Some vehicles also use transmission fluid in their power steering system, so a power steering leak is another possibility.)

Determining the source of a transmission leak usually only involves a quick and inexpensive visual inspection, after which we can provide an estimate for any repairs you might need.

All of our quality, lasting transmission repairs are completed by a journeyman technician, and backed with the best parts and labour warranty in Airdrie.

How do I check my transmission fluid level?

checking transmission
This transmission is checked and filled through this plug underneath.

On older vehicles, checking the transmission fluid is usually accomplished using a dipstick similar to the engine oil dipstick. Transmission dipsticks are often red or black, while engine oil dipsticks are usually yellow. Most newer vehicles have made things a little trickier. Many of today’s cars and trucks feature transmissions that have to be checked from underneath the vehicle, or using special tools.

Contrary to popular belief, this is not because car companies want to “make things more difficult, so you have to take your vehicle to the dealership.” Instead, manufacturers have done this to protect their increasingly complex transmissions. Because transmission fluids have become so specific, they do not want an untrained person to damage their transmission by adding the wrong fluid, or setting the fluid level incorrectly.

Replacing automatic transmission fluid in Airdrie:

If you’re looking for the best quality transmission service in Airdrie, we’re here to help! Your transmission will only be serviced by a journeyman technician with the skill and experience to do all the little things right. They will only install high quality, genuine OEM fluids and filters.

Do you have any transmission-related questions? Wondering what a transmission service for your vehicle would cost? Please don’t hesitate to get in touch with us at any time!