How to Check Transmission Fluid Without Dipstick


May 09th, 2022

How to Check Transmission Fluid Without Dipstick

Checking a vehicle’s transmission fluid is one of the most fundamental maintenance tasks that everyone should know how to do. But what happens if your car doesn’t have a dipstick necessary to check that fluid?

Newer car models have a sealed transmission that doesn't feature a dipstick. Checking the transmission fluid requires you to open the inspection plug on the transmission side. Excess and dirty fluid will flow out automatically. If it needs fluid or refill change, you can do so through the fill plug on top of the transmission.

If you’re not familiar with sealed transmissions or checking fluid levels without a dipstick, you’ll want to keep reading. Checking sealed transmissions is easier than it sounds, and you’ll discover the step-by-step process below.

How Do You Check the Level of Transmission Fluid Without a Dipstick?

Most drivers, especially us from another age and time, know for a fact that you need a dipstick to check the level of transmission fluid. So, I can imagine your surprise (and maybe confusion) when you first realized that your car’s transmission is missing this measuring device.

OK, it’s just a stick with markings, so don’t panic too much. 

The truth is that an increasing number of cars these days do not have dipsticks. As newer car designs get more streamlined, it’s becoming increasingly common for vehicles to be missing the dipstick that most of us knew since we were teens.

Step-by-Step Guide for Checking Transmission Fluid Without Dipstick

If you’re wondering how to check transmission fluid without dipstick, you’ll be glad to know that it’s very quick and easy to do. One might even argue that it’s easier to check these newer transmissions than rely on the old-fashioned dipstick.

Here’s how they work:

Step 1: Confirm That There’s No Dipstick 

First and foremost, you must confirm that your car model has a sealed transmission, meaning it doesn’t rely on a dipstick to check the level of the fluid.

You see, it’s not enough to assume that your transmission has no dipstick just because you can’t find it. Instead, check your car owner’s manual or perform an up-close inspection to confirm that your vehicle’s transmission is indeed a sealed one.

Once you're sure and 100% confident, you can continue to Step 2.

Step 2: Locate Inspection Plug and Fill Plug

If you’ve confirmed that you have a sealed transmission, how are you going to check, refill, and change the fluid?

A sealed transmission has an inspection plug and a fill plug instead of a dipstick.

The fill plug is where you’ll pour transmission fluid in, while the inspection plug is where excess fluid will automatically flow out of the transmission. You’ll see more about this in the following steps.

You’ll most likely find the inspection plug by the transmission’s side and the fill plug somewhere on top.

Remember: Check the car owner’s manual to be sure.

Step 3: Get the Car to the Correct Temperature

Once you know where everything is, it’s time to warm up that transmission fluid. The fluid must be at the correct operating temperature (i.e., not too hot, or too cold) to get an accurate fluid check.

You can take your car out for a quick drive around the neighbourhood to raise the transmission fluid’s temperature. For a more precise reading, use an onboard diagnostics scanner to see the transmission fluid temperature in real-time.

The ideal transmission fluid temperature will differ between vehicles. So, again, check your car owner’s manual to see what yours should be.

Step 4: Put in Park, Keep Idle

When the transmission fluid is at the correct temperature, park your car and let it idle. Never forget: Your car must always be on a level surface to ensure that you’re performing a transmission fluid check correctly.

Parking your car on the ground should still allow you to access the inspection plug on your sealed transmission. However, if that’s not the case with your particular car model, you’ll have to lift the car evenly on jacks or use a lift.

Step 5: Open Inspection Plug 

Next, it's time to open the inspection plug on your sealed transmission. Wear protective gloves because the parts you'll touch will be hot enough to injure your fingers. 

Prepare a drain pan underneath the car to catch any excess transmission fluid that flows out.

Step 6: Check Your Transmission Fluid 

Now, here’s what’ll happen when you open the inspection plug, what it means, and what you should do about it:

  • If transmission fluid flows out: Any transmission fluid that flows out after opening the inspection plug is excess fluid, so let it flow out uninterrupted. Once the flowing stops, it means your car’s sealed transmission has the correct level of fluid left inside.
  • If transmission fluid doesn’t flow out: When you open the inspection plug and nothing comes out, that means there is too little or just enough fluid. Slowly add more fluid through the fill plug until its excess flows out of the inspection plug. Let the excess fluid flow out and wait till it stops, at which point you know that what’s left inside is the correct amount.
  • If dark brown or black transmission fluid flows out: When you see dark brown or black transmission fluid coming out of the inspection plug, that means the fluid inside has gone bad. You’ll have to empty the transmission and refill it with new transmission fluid.

Should You Be Checking Transmission Fluid Hot or Cold?

You should only check your transmission fluid when it’s hot, but only at the ideal operating temperature. Your check won’t get an accurate result if it’s done while the transmission fluid is too hot or too cold.

For the most accurate reading, use an onboard diagnostics scanner that has a transmission fluid temperature feature. This will help you monitor the exact temperature while driving or idling the car.

When Should You Check the Transmission Fluid?

Ideally, you should check your transmission fluid once a month. However, you’ll want to do that more often if you drive more than the average car owner.

Putting above-average mileage on your car will expose it to extra wear and tear, affecting your transmission and the fluid inside.

Regular checking and replacing (if necessary) of oil will keep your transmission functioning at its best and also help to maximise its lifespan.

What Happens If You Don't Check Your Transmission Fluid?

The role of transmission fluid is crucial. It’s what keeps all moving parts of a car lubricated and clean while removing excess heat. If you do not check the transmission fluid and there’s not enough of it, your car’s transmission will wear out quicker and fail sooner than it should.

Here’s another way to look at it. Checking your transmission fluid regularly only takes a bit of time and money. Neglecting it will lead to major problems, involving more expensive repairs that can keep your car in the workshop for long periods.

Looking for transmissions or transmission parts? Check out the marketplace at CarpartAU, where you can find excellent deals on used parts.

By Ray Hasbollah