Transmission fluid is a lubricating liquid designed to keep components in the transmission moving properly and temperatures within cool. When it gets dirty, it may change from its original red or green coloring to brown or black. The fluid discoloration signifies you need to change your transmission fluid and filter, though this also depends on whether you have an automatic or manual transmission, car type, and how you drive. Service manuals will also include specified intervals of when you should change your transmission fluid usually every 30,000 miles.
3 Types of Transmission Fluid:
Automatic Transmission Fluid:
Designed for cars with automatic transmission and some newer manual cars, automatic transmission fluid helps with lubricating gears, brake band friction, and valve operation. It is made from reshaped hydrocarbons in crude oil and catered toward specific cars.
Manual Transmission Fluid:
Manual transmission fluid is typically made from a variety of different oils, such as regular motor oil, even heavier hypoid gear oil, and other heavy metals like lead. It is exclusively used in manual cars.
Synthetic Transmission Fluid:
Synthetic transmission fluid is made from pressurized and temperature-regulated chemical reactions to make the ideal fluid. It's built to oxidize less and not break down or thin out in high temperatures. Different car manufacturers may recommend synthetic fluid over traditional depending on each model's needs.
Collect old fluid from transmission flush.
Make sure the drain pan you use is large enough to handle up to 3-gallons worth of liquid.
Pour fluid from the drain pan into a leak-proof container.
Use a funnel to avoid spilling. A sealed plastic bottle or a milk jug will often do the trick. Make sure the container is clean of any other liquids or oils, as most collection facilities will not accept mixed fluids, and that the lid seals tight. Store it in a safe place away from children or pets.
Find a local automotive fluid collection site.
Some local waste facilities will accept your used transmission fluid along with other automotive fluids. Check your local government offices to find a household hazardous-waste accepting location near you.
Drop off old transmission fluid for disposal. There are few waste management groups that will come and pick up old transmission fluid, so you will most likely need to take it in yourself.