Home CAR GUIDE How to Check Car Transmission fluid

How to Check Car Transmission fluid

Transmission fluid is a fluid that helps to keep metal parts inside your gearbox from grinding down. This fluid also helps to keep the different parts of your transmission cool. Shifting mechanical gears is quite a hard task for your car. Transmission fluid allows your car in shifting with ease while protecting the metal parts that rub against each other from wearing down.

Transmission fluid is used for lubricating the components of a car’s transmission for optimum performance. In vehicles having automatic transmissions, the fluid also acts as a coolant. There are several types of auto transmission fluids, and the type used in individual cars and trucks will depend on the type of transmission inside. Automatic transmissions utilize regular automatic transmission fluid, as the name suggests. Manual transmission fluid can vary, using either plain motor oil, a transmission oil called heavyweight hypoid gear oil, or automatic transmission fluid. The type of transmission fluid to be used in vehicles with standard transmissions can generally be found in the maintenance section of the owner’s manual.

While the primary function of auto transmission fluid is of lubricating the various parts of the transmission, it can serve other functions like:

•    Cleaning and protecting metal surfaces from wearing out.

•    Condition gaskets.

•    Enhance cooling function and reducing high operating temperatures

•    Increase rotational speed as well as temperature range

Different types of transmission fluid

There is also a myriad of different types of transmission fluid that go beyond merely dividing between automatic as well as manual transmissions. For achieving the best performance under high temperatures and extend the fluid’s life fully, use the transmission oil or fluid recommended by your vehicle’s manufacturer, which is usually found in the owner’s manual:


These varieties, available in different quality grades, are the most commonly used automatic transmission fluids nowadays and contain friction modifiers to best protect the internal surfaces of the transmission.

HFM Fluids

Highly Friction Modified (HFM) fluids are much like Dexron and Mercon types, but the friction modifiers in them are more effective as compared to them.

Synthetic Fluids

These types of fluids usually cost more than Dexron or Mercon, but they are made to better withstand drastic temperature changes and greatly reduce friction, oxidation, and shearing.


This type of automatic transmission fluid is used almost exclusively in vintage 70s model vehicles and does not have friction modifiers.

Hypoid Gear Oil

 Used in certain manual transmissions, this type of transmission oil is highly resistant for extreme pressures as well as temperatures.

Motor Oil

Although motor oil is generally used in a vehicle’s engine, it works in  a pinch to lubricate manual transmissions because it has a similar composition and properties to that of gear oil.

Depending on the type of vehicle you own and the length of ownership, you might never need to worry about the type of transmission fluid you use. That’s because it’s not important to change it frequently. In fact, some automatic transmissions might never require the fluid to be changed, although most mechanics recommend changing it every 60,000 to 100,000 miles. Manual transmissions need more frequent transmission oil changes, usually every 30,000 to 60,000 miles.

How to Change Transmission Fluid

How to Check Transmission Fluid

Step 1- Open the hood of your vehicle and find the transmission fluid dipstick.

Check your owner’s manual for determining if the vehicle needs to be running or off for accurately measuring the transmission fluid.

Step 2- Pull the dipstick out with the handle and wipe any oil residue off the stick. Re-dip the stick till it’s fully seated, and pull out to see the oil level.

Wiping it makes sure you’re measuring the accurate oil level and not any residue that might falsely indicate higher levels.

Transmission Fluid Change Instructions

Step 1- Use a car floor jack for raising the vehicle off the ground using the manufacturers’ recommended lift points to avoid damaging the undercarriage.

While using a jack, exercise caution to ensure no accidents take place. Always secure the vehicle with jack stands, ramps or with cribs. We recommend installing wheel chocks to the opposite end being lifted for preventing the vehicle from rolling.

Step 2- Place a container or drip pan under the transmission oil pan for catching the old oil.

•    Before draining the fluid, ensure the transmission is at normal operating temperature. Also, ensure there’s a fill spout for the new fluid; some newer transmissions can do away with traditional fill methods.

•    Loosen the pan bolts to allow for draining. Once it becomes loose, the fluid will immediately gush out; the fluid might be hot, so use caution.

Tip to help keep things clean: Removing all but the last four bolts at the back of the pan helps fluid to drain with minimal splatter.

Step 3- Replace the transmission pan gasket as well as the filter.

•    Ensure the transmission pan and transmission mating surfaces are clean, and that the old filter grommet and transmission pan gasket are removed before installing the new parts.

•    Once completely drained, and with the new filter and gasket in place, just tighten the transmission pan bolts.

Step 4- For filling the new fluid, open the hood and pull out the automatic transmission fluid dipstick. Insert a funnel. After that, pour the new transmission fluid through the funnel.

•    Check your owner’s manual for the recommended type as well as quantity of transmission fluid.

•    Pull the funnel out and reinstall the dipstick and close the hood.

•    Check the oil level to ensure it’s in the right operating range, which will be indicated on the stick. If it’s low, just top off with the manufacturer’s recommended oil.

•    While checking the fluid, also check the condition of the fluid. If it’s old, the fluid tends to get darker, and in some cases, you can also smell a burnt odor; the latter might suggest the transmission could use service. Be sure to follow your manufacturer’s recommended fluid change intervals which are found in the owner’s manual.

Video of How to Change Automatic Transmission Fluid in Your Car

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