Automatic Transmission Fluid
Vehicles that come without a clutch pedal rely on an automatic transmission to deliver power, released during the combustion process, to the wheels. This type of automotive transmission allows for choosing a correct gear ratio without human participation, taking a driving experience to the next level. Driving a vehicle with an automotive transmission, you enjoy smooth gear shifting, which is mainly achieved by the use of special fluid, known as automatic transmission fluid or oil.
Automatic transmission fluid is a special type of oil, containing different additives to improve its lubricating, hydraulic and cooling qualities. Thanks to the use of this fluid, your transmission parts wear slower, withstand rust and corrosion, and do not overheat during transmission operation. Automatic transmission fluid lubricates, cleans and protects all moving parts, preventing them from damage. It also improves velocity and reduces oxidation to prolong the service life of your transmission components. Last but not least, your transmission fluid maintains thickness at different temperatures, allowing for safe cold starts.
While the most common color of automatic transmission fluid is red, you may also find it in another color, but it’s always different to other fluids in a vehicle. This is very helpful when it comes to identifying fluid leaks.
How automatic transmission fluid works
When your vehicle is running, moving parts inside your automatic transmission cause the fluid to circulate through them. While flowing, the fluid lubricates all the parts, preventing them from excessive wear and overheating.
Unlike engine oil, automatic transmission fluid doesn’t have to deal with byproducts of combustion, which means it can last longer than any motor oil, so you don’t need to change it every 10000 miles. At the same time, like any other fluids, it collects different contaminants, but most of them are products created by wearing of moving transmission parts. On some vehicles, you won’t even find a dipstick to check the fluid level as their manufacturers supposed the fluid to last the life of the vehicle. Although, if your transmission does feature a dipstick, this means the fluid should be changed according to your owner’s manual recommendations.
When replacing automatic transmission fluid, use the manufacturer’s recommended type found in your owner’s manual.
How to understand you have poor transmission fluid
Just like any other fluid in a vehicle, your transmission fluid loses its lubricating and cleaning qualities as it ages. Here are the common signs of bad transmission fluid:
Low transmission fluid level
If you have a dipstick, you can check the level of fluid in the transmission. Top it up if it is below the full mark. In case you have to repeat this procedure on a regular basis, inspect your transmission for fluid leaks. If there is any, it should be fixed by a professional.
Transmission fluid is dark or has contaminants
While transmission fluid can get darkened over time, it shouldn’t change its color. Take off the dipstick to check the fluid. If it is dirty, becomes brown or black, or smells burnt, you should contact your mechanic for advice. He or she will inspect the transmission system for malfunctioning. If the transmission is in good condition, you would just need to change the fluid.
It is very important to follow the manufacturer’s recommended change intervals because it can be problematic to flush the system if you ignore them.
Transmission fluid leaks
A fluid leak may lead to an improper fluid circulation inside the transmission, so its components can wear out faster than they should. Once any leak is detected, you should get in touch with your mechanic no matter whether you can top up the fluid or not.
Your transmission malfunctions
In the worst-case scenario you may experience problems with shifting and overheating. You can also notice abnormal noises coming from the transmission. In this case, you should stop the vehicle and have it towed to a repair shop even if there is no fluid leak.
Automatic transmission fluid maintenance
If your transmission features a dipstick, the best you can do to prolong the life of your transmission is to check the fluid level regularly and to top it up if necessary. You should also change the fluid and flush the system at the manufacturer’s recommended intervals found in your owner’s manual.