When you buy through links on our site, we may earn a commission. Learn more here.

Is Power Steering Fluid The Same As Transmission Fluid?

Cars have many moving components, and to keep things running smoothly, they often need assistance in the form of fluids. 

Two of these, transmission and power steering fluid, are essential for keeping your car in top condition. 

But can you use one in place of the other? 

We’re exploring how both work and whether you can use them interchangeably. 

The Differences Between Power Steering Fluid and Transmission Fluid

Hand pouring transmission fluid through funnel

To understand if you can use the two fluids interchangeably, you need to know what each does. 

The critical difference between the two is that power steering fluid is used on the power steering pumps to make them level and smooth. 

Transmission fluid is used on the seals and gears within the transmission to keep it lubricated and to work smoothly.

Additionally, it keeps the transmission unit cool, stopping the engine from overheating. 

You will know transmission fluid needs a change if your car starts shaking.

This usually happens when you drive at faster speeds. 

It’s essential to take note when driving so your car doesn’t overheat or even worse.

This can cost much more than a simple change of your transmission fluid. 

Whereas power steering fluid usually only gets a change when there is an issue in the pump that you’ll notice if there is a strange smell or the liquid is black. 

Power steering fluid

Power steering comes with most modern cars; it helps make the steering wheel easier to move.

You will definitely tell the difference if you’ve driven an older car.

It can take some serious arm muscles to make a slight turn. 

Knowing this, we can better understand what the power steering fluid actually does within the power steering systems. 

Power steering fluid is a type of hydraulic fluid that keeps the power steering system lubricated.

To keep the steering from sticking or becoming hard to maneuver. 

Additionally, power steering fluids allow the entire power steering pump system to move the two front tires easily.

Appearance-wise, power steering fluid can come in various colors, like orange, pink, and light red.

It should remain clear and maintain its color. 

If you notice any color or clarity change, it’s time to replace the fluid.

But generally, it is recommended to change the power steering fluid every 75,000 miles or five years. 

Transmission fluid

Similarly, transmission fluid acts as a lubricant but for the gearbox rather than the power steering. 

If you think about driving a manual car, changing gears is repetitive, moving up and down.

Movements like this can often leave a gearbox quite warn, making it stick. 

That’s where transmission fluid comes in; it lubricates these movements to ensure they happen effortlessly. 

Without the lubrication, the components can rub together, creating friction, which is the last thing you want in a gearbox. 

There are two different types of transmission fluid:

  • Automatic: Used in automatic cars and is slightly thinner than manual fluid. Automatic transmission fluid acts as a lubricant, helping with hydraulic pressure in an automatic car, and cooling down the transmission system. 
  • Manual: This transmission fluid is specifically for manual cars because the thicker consistency keeps things moving in the gearbox and the clutch. However, some newer manual vehicles are compatible with automatic transmission fluid. 

One of the main ways to tell if your transmission fluid is still working as it should is through the color:

  • Red: It is new and working as it should. 
  • Orange: Getting a bit older but still working well. 
  • Light brown: It is moving towards needing a change quite soon. 
  • Pink: Transmission fluid should never be pink; this means there is water in the system which can cause a serious problem. 

Can You Interchange Transmission Fluid and Power Steering Fluid? 

No, you can’t use the two interchangeably.

However, you can use transmission fluid as a power steering fluid. 

Since the two hydraulic fluids have similar consistencies and properties by nature, it’s easy to see why this is possible. 

Transmission fluid can also help to remove any debris or dirt in the power steering system, which is a big pro. 

But you should only do this if you’re in an urgent situation where you don’t have the proper power steering fluid for your vehicle. 

Note manual and automatic transmission fluid are different, and manual transmission fluid isn’t an option for replacing power steering fluid. 

Now, onto the transmission fluid; you CAN’T use power steering fluid in its place.

It can damage your entire gearbox system. 

While the two are similar, the power steering fluid doesn’t have the needed modifiers in the transmission fluid. 

These modifiers remove the build-up of grime and dirt that can make a gearbox stick. 

Mixing Transmission Fluid and Power Steering Fluid

It isn’t advised to mix power steering fluid and transmission fluids as they may not act efficiently.

Combining the two in the transmission system can cause your hydraulic system as a whole to fail, which is very expensive. 

Key Things to Note 

  • Always read your car manual to ensure you’re using the right products.
  • If you’re unsure, consult a mechanic. 
  • Only use fluids compatible with your vehicle. 
  • Take note of how your fluid looks every year and change it when necessary. 

The tl;dr

Can you use power steering fluid instead of transmission fluid?

No, the power steering fluid does not have the properties to adequately clean and maintain the transmission system.

What happens if I put transmission fluid in my power steering?

It should work the same, granted you use the correct fluid, for example, manual or automatic.

But transmission fluid is generally okay to use in a power steering system and might even provide an excellent clean.