DIY Guide: How to Change Automatic Transmission Fluid in Your Subaru – Improve Performance and Extend Transmission Life

As a Subaru owner, you already know the importance of regular maintenance to keep your car running smoothly. One crucial element to maintain is the automatic transmission fluid. Over time, debris and contaminants can build up in your car’s transmission, causing it to work harder and deteriorate faster. Changing the transmission fluid can improve your car’s performance and extend the life of its automatic transmission.

In this article, we’ll provide you with a step-by-step guide on how to change the automatic transmission fluid in your Subaru vehicle.

Why You Should Change Your Subaru Transmission Fluid

Before we delve into the specifics of changing Subaru’s automatic transmission fluid, it’s important to understand the benefits of doing so.

  • Improves Transmission Performance: Old or dirty transmission fluid can cause shifting problems, slipping gears, or sluggish acceleration. Fresh transmission fluid will ensure that your vehicle’s gears are shifting effortlessly.

  • Extends Transmission Life: Changing the transmission fluid regularly can help prevent expensive transmission damage. New fluid will keep everything moving smoothly and reduce wear and tear on the transmission’s mechanical parts.

  • Saves You Money: Changing the automatic transmission fluid periodically is a tiny investment compared to the cost of repairing or replacing a damaged transmission. By doing it yourself, you can save even more money.

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Now that you’re aware of the benefits, let’s get started on the DIY process of changing your Subaru’s automatic transmission fluid.

What you will need to change Subaru Automatic Transmission Fluid

Before you dive into the task, make sure you have the following tools and materials.

  • Ratchet and sockets
  • Screwdriver
  • Funnel
  • Drain pan
  • Jack
  • Jack stands
  • New automatic transmission fluid
  • Cleaning solvent

It’s important to ensure that you use the correct type of fluid as specified in your Subaru owner’s manual. Using the wrong kind of fluid can cause transmission problems.

Step-by-Step Guide on Changing Subaru Automatic Transmission Fluid

After you’ve gathered all the necessary materials, it’s time to start the fluid changing process.

Step 1: Prepare Your Vehicle

Start by turning off your engine and ensuring your Subaru is on level ground.

Step 2: Locate the Transmission Fluid Pan

Locate the transmission fluid pan under the vehicle, which is typically located at the bottom of the transmission. Place the drain pan under the pan to catch any spillover.

Step 3: Drain Old Fluid

Remove the bolts holding the pan and carefully remove the pan. Drain old fluid by slowly tilting the pan until the fluid runs out.

Step 4: Clean the Pan and Magnet

Clean the pan using cleaning solvent, and use a magnet to remove any metal shavings or debris from the pan.

Step 5: Replace the Filter

Remove the old transmission filter and replace it with a new filter.

Step 6: Add New Fluid

Locate the transmission dipstick and remove it. Slowly add the new transmission fluid with a funnel until the fluid level reaches the "full" line on the dipstick.

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Step 7: Reassemble Everything

Reattach the transmission pan and tighten the bolts to the manufacturer’s specifications. Clean up any spillover.

Step 8: Test Drive the Vehicle

Test drive your Subaru and confirm that it shifts correctly.

How Often to Change Your Subaru’s Automatic Transmission Fluid

Subaru recommends changing the automatic transmission fluid every 30,000 to 60,000 miles, depending on your driving conditions and habits. Frequent stop-and-go driving or hauling heavy loads can cause the fluid to break down more quickly. However, if you do a lot of highway driving, you can extend the time between changes.


Congratulations! You’ve successfully changed your Subaru’s automatic transmission fluid, improving its performance, and extending your transmission’s lifespan. By doing this simple maintenance task periodically, you can save money and ensure your Subaru continues to run smoothly. With our step-by-step guide, you can now do this task yourself and enjoy the benefits of a well-maintained Subaru.


Q: Can I change the transmission fluid without changing the filter?

A: It’s highly recommended to change both the fluid and filter together to keep your transmission in tip-top shape.

Q: Can I use any transmission fluid in my Subaru?

A: No. You must use the type of transmission fluid specified in your Subaru owner’s manual to avoid transmission problems.

Q: Can I flush my transmission instead of changing the fluid?

A: While flushing may sound like a time-saving option, it’s generally not recommended. Flushing can dislodge debris that can become lodged in the transmission, causing more harm than good.

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Joseph Weaver

With a background in engineering and a passion for cars, Joseph brings a unique perspective to our blog. He's particularly interested in the technology and innovation behind Subaru's advanced safety features, and his articles on this topic are always insightful and informative. When he's not writing, he enjoys playing video games and spending time with his family.

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