How to check transmission fluid level and quality

Manual transmissions consist of bearings, shafts, internal gears, and synchronizers that allow the driver to shift gears. Many manual transmissions are lubricated with heavy petroleum-based oil. When this oil leaks, contaminated or empty, its lubricating properties will break down, making your manual transmission noise or even jammed.

Because transmission fluid is an important fluid in your car, the fluids need to be replaced regularly. If your transmission fluid is leaking or never replaced, it can cause damage to your transmission.

So here is step by step to check transmission fluid level and qualit. Still, before that, you need to prepare some items for better manual transmission fluid checking.

Items to prepare before we check transmission fluid level and quality :

Carjack, and jack stands
Ratchet with socket (standard and metric) or use the same socket size with transmission fluid filler plug
Torque wrench
Dusting cloths
Mechanic creeper (optional)

Two important things when checking manual transmission fluid, the transmission fluid level and the color quality of the transmission fluid. Here's how :

I. How to check transmission fluid level

Checking manual transmission fluid level has the purpose of ensuring your transmission has enough transmission fluid so it can lubricate transmission components as well. Most car manufacturers set the transmission fluid level just the same as the height of the filler plug on the transmission body.

For better checking, you need to put your car on a flat and straight surface, as well as if you were jacking up the car. Here's how to check manual transmission fluid level

1. Jack up the vehicle

Use a car jack to lift the vehicle. Lift the front of the vehicle on sides at the manufacturer's suggested jacking points. Place the jack stands under the manufacturer's lifting points and lower the vehicle onto the jack stands. Do the same things with the vehicle's rear end (lift the end of the vehicle, and place the jack stands). Lift it just high enough for you to gain clearance underneath.

Lifting the front and rear of the vehicle means getting a flat and straight vehicle position while checking the manual transmission fluid. Lifting in only one side can make the wrong level fluid position.

2. Locate the fluid fill plug.

Most of the time, the filler plug is a large bolt located about halfway up the side of the transmission. Look at the images below, for example, the filler plug for Front Wheel Drive (FWD) and Rear Wheel Drive (RWD) manual transmissions.

For the correct location of the filler plug of your car, you must refer to your car service manual book.

3. Remove the filler plug

Using the ratchet and the socket that fits snug on the filler plug, remove the filler plug. Unscrew it slowly to prevent if there is any oil from flowing out from the plug hole.

4. Check transmission fluid level

Check the fluid level per the manufacturer's specifications from a repair manual. Most car manufacturers put a manual transmission fluid level that is about the same as the filler hole. You can check by placing your finger into the filler plug hole and seeing if you get some fluid onto the end of your finger.

Look at the example image above for manual transmission fluid level checked. If you don't get some fluid onto the end of your finger, then the fluid is low. If there is fluid at that level, then no additional fluid is needed.

Related Articles:

II. Checking manual transmission fluid quality

Checking the fluid level is the first important thing to do. After that, besides the level, you have to check the transmission fluid quality. There are two things to consider when checking fluid quality. First by the color of the fluid, second is by the usage mileage.

The transmission fluid color can show how its condition. Good transmission oil has clear colors such as clear red, clear yellow, or clear greeny. The bad transmission oil has dark colors such as dark gray, dark brown, and sometimes we can see the color of the fluid changes to be black. The dark color means the fluid is overused and over mileage.

And sometimes, we can see other color changes of the transmission fluid that look like milk. If this happens, your transmission fluid is contaminated with water, and we should replace it as soon as possible.