How to Fill the Transmission Fluid in Your 2018 Subaru Forester: A Step-by-Step Guide

If you’re a Subaru owner who likes to take care of your car, you might want to know how to fill the transmission fluid in your 2018 Subaru Forester. Filling transmission fluid is an important part of basic maintenance that can keep your car running smoothly. In this article, we’ll cover everything you need to know about filling the transmission fluid in your Subaru Forester.

Importance of Transmission Fluid

Transmission fluid is a crucial element in ensuring your car’s transmission system is running smoothly. Its primary function is lubricating the moving components of the transmission, which works to reduce friction and heat buildup in the engine. It also maintains the hydraulic pressure needed for the transmission system to function properly and helps to cool the gears to prevent overheating and damage.

As a rule of thumb, it’s important to check your car’s transmission fluid level and color every 6 months, although the recommended frequency can vary depending on your car’s manufacturer.

Tools Required to Fill the Fluid

Before starting, you should gather the necessary tools that you’ll need to fill the transmission fluid in your Subaru Forester. Some of these include:

  1. Transmission fluid
  2. Funnel
  3. Ratchet wrench
  4. Jack stands or a hydraulic jack
  5. Level ground or an oil drain pan

Steps to Fill the Fluid

Here’s a step-by-step guide to filling the transmission fluid in your Subaru Forester:

  1. Locate the fill plug. The fill plug is usually located on the transmission’s side and can vary in position depending on the car model. You can consult your car’s manual for exact location.

  2. Place the jack stands or hydraulic jack under the car and raise it to get better access to the transmission.

  3. With the ratchet wrench, remove the fill plug and attach the funnel into the opening to prevent spilling.

  4. Slowly pour the transmission fluid into the funnel. Be careful not to overfill. You can check the transmission fluid level with a dipstick, which should be marked with minimum and maximum fill levels.

  5. Re-insert the fill plug and tighten it with a ratchet wrench.

  6. Lower the car from the jack stands or hydraulic jack and ensure the transmission fluid is at the required level.

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Precautions to Take

When filling transmission fluid in your Subaru Forester, there are a few precautions you should take:

  1. Before adding the fluid, ensure that the vehicle is on level ground.
  2. Slowly pour the fluid into the transmission, being careful not to overfill.
  3. Ensure that you’re using the correct type of transmission fluid by consulting your car’s manual.
  4. Wear gloves, as transmission fluid can be toxic and cause skin irritation.

How Frequently the Fluid Should be Checked and Changed

It’s essential to check your car’s transmission fluid regularly – generally every six months – even if you’re not experiencing any issues with your car. However, depending on your driving habits and car model, this frequency can change. It’s recommended that manual transmission fluid be changed every 30,000 to 60,000 miles. On the other hand, automatic transmission fluid should be replaced every 60,000 to 100,000 miles, depending on how your car is used.


Q: What happens if I overfill my transmission fluid?

A: Overfilling transmission fluid might cause pressure to build up inside the transmission. This pressure buildup can cause oil seals or gaskets to fail.

Q: What type of transmission fluid should I use in my Subaru Forester?

A: The specific type of transmission fluid recommended for your Subaru Forester is specified in your car manual.

Q: Can I change transmission fluid myself?

A: Yes, you can, but it’s recommended to have a mechanic do it. Most mechanics have specialized equipment that can flush the old fluid adequately from the system.


Filling transmission fluid in your 2018 Subaru Forester is a simple and easy process. Regularly checking your transmission fluid level and color can help keep your car running smoothly, and prevent some expensive repairs. Follow the above steps, and you’ll be able to fill your transmission fluid in a quick and easy way.

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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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