Is It a Good Idea to Change Your Car's Automatic Transmission Fluid by Yourself?

Posted on: 10 January 2023

Most people understand how important it is to change their car's oil and lubricants as recommended by its manufacturer. Usually, this will involve removing the drain plug, evacuating the old fluid, changing the filter, and adding replacements. However, this may not be enough if the vehicle has an automatic transmission system. So if you're thinking about draining your car's automatic transmission by yourself at home, why should you pause for thought and consider another option?

Additional Complications

An automatic transmission is very different from its manual counterpart. While the goal is the same—to select the most appropriate gear for the road conditions—some additional components within the automatic system take driver input out of the equation.

One of these components is known as a "torque converter." It's one of the largest parts and sits at the front of the transmission casing right next to the engine's flywheel. As the name implies, this part is meant to convert the torque produced by the engine so it can be used to change gears automatically. It does this cleverly by pressurising the hydraulic fluid (lubricant) and spinning it through an impeller. The fluid moves at high speed but some of it remains within the torque converter casing as part of the process.

Problems Arise

When the driver switches the engine off at the end of the journey, some of this lubricant will dry and may attach to the casing wall. At the start of the next journey, most of the lubricant will continue to flow, but some of it will remain stuck to the wall. And this is where a problem may develop should you decide to change the automatic suspicion fluid yourself.

Half a Job

If you remove the drain plug and let gravity evacuate much of the lubricant, some will remain within the torque converter casing. This is not a good idea as some of that hardened lubricant may break away and interfere with mechanical operation, leading to failure in the future.

Your Best Approach

So, the best approach is to take the vehicle to an experienced mechanic. They will have a machine that they can connect to the transmission and pump a cleaning solution through the torque converter to get rid of the hardened lubricant. This machine will then refill the system with new fluid, and this comprehensive process will help extend the life of the transmission. 

For more information about automatic transmissions, contact a local auto shop.