Just like the engine needs oil to lubricate the different components and parts and protect them against wear and corrosion, transmission is also lubricated by a special fluid called transmission fluid.

It’s very important to maintain the proper transmission fluid level in order to keep your transmission shifting properly and your car running smoothly.

How can you check your transmission fluid?

Step1: Check your owner’s manual. Does your car have a manual or an automatic transmission? Manual transmissions don’t usually have a dipstick. They are factory filled and no top-up is needed. The fluid has only to be changed in the event of repairs.

Step2: If you have an automatic transmission, locate the transmission dipstick. The transmission fluid dipstick is usually red (yellow or white for the engine oil dipstick). The owner’s manual will guide you to find it. Sometimes it is labeled.

- On rear-wheel drive vehicles, the dipstick is usually on the passenger side of the engine compartment, near the back of the engine.

- On front-wheel drive vehicles, the dipstick is usually on the driver’s side, on one side of the transmission. If you can’t find it, your owner’s manual should show you where to look for it.

Many cars don’t have a transmission dipstick. The oil level may have to be checked using an electronic device or by removing a screw in the transmission housing. Checking fluid levels in a sealed transmission is a much more complicated process. The average car owner may not be able to check the transmission fluid level. If your car doesn’t have a dipstick, your local transmission shop or dealership can check the level. A good time to do this is while you’re changing the engine oil.

If your car has a transmission dipstick, you should check the transmission oil level regularly.

Step3: How to check transmission oil?

You can do the following: Remove the stick, wipe it with a clean cloth, reinsert it, leave it in for 5 seconds, then pull back out and check. If it’s necessary, add some oil. Don’t forget to use the oil recommended by the manufacturer.

Add only a small quantity at a time, checking the level with the dipstick each time. It's easy to add, but difficult to remove it if you add too much.

If the transmission requires more than a quart or is using oil regularly, take your car in to have it checked for leaks.

How to properly check transmission fluid? You can also check the color and smell.

Color is basic for transmission fluid. It should not be different from its normal light brown, semi-transparent appearance. Automatic transmission fluid (ATF) is a cherry red. If it is dark red or brown, you should have your fluid changed.

If it smells burnt or has particles in it, you should also have your transmission serviced. What is a transmission service? It consists of changing the transmission fluid filter before adding the transmission fluid.

Automatic transmission fluid

Automatic transmission fluid (ATF) is the fluid used in vehicles with automatic transmissions. It has usually red or green color.

Automatic transmission fluid is very important for the transmission. The fluid produces the hydraulic pressure needed to operate the transmission. It cools and lubricates the transmission as well. When the fluid level is low, the pump may draw air into the system. Air in the hydraulic system interrupts the proper flow of automatic transmission fluid so damage is very likely to occur when transmission fluid is low.

How to check automatic transmission fluid level?

For transmissions having a dipstick, the procedure is the same as described above.

Many brands such as Ford, Toyota, GM and other vehicles have no longer an automatic transmission dipstick for checking the fluid level. Automakers are eliminating automatic transmission dipsticks. Newer transmissions are more complex than older ones and the transmission fluid levels are far more serious. Particular procedures are required to check the automatic transmission fluid level in these models.

Learn how to change automatic transmission fluid:

• Drain the transmission fluid: First of all, disconnect the cooling line running from the transmission to the radiator. Then, connect a piece of rubber tubing to the pipe and place the free end of the tube in an empty container. Start the engine and let it idle. Transmission fluid should flow out of the cooling line and into the container. When the fluid stops flowing, turn off the engine. You can then reconnect the cooling line to the radiator.
• Remove the bolts holding the drain oil pan to the bottom of the transmission.
• Clean the drain pan with transmission fluid.
• Replace the filter.
• Replace the gasket.
• Replace the pan: As soon as the filter and gasket are in place, put the pan back on the transmission. Hand-tighten the bolts for the first few turns so that you don't strip the threads. Then use a torque wrench to finish tightening the bolts. Do not overtighten the bolts as you will damage the threads in the transmission and dent the pan.
• Fill with automatic transmission fluid: Dexron III ATF is the most common, but refer to the owner's manual to choose the appropriate automatic transmission fluid. Check also the amount.