Possible Causes of Colors in Transmission Fluidby Jen DavisUpdated July 08, 2023
Automatic Transmission Fluid
Transmission systems are crucial internal components to a functioning car. A vehicle’s transmission fluid color is one of the best early warning signs of transmission problems, so it is important to check your own fluid or have it checked as part of your regular vehicle maintenance program. Transmission fluid can be surprisingly colorful, especially if you've never seen it before and don't know what to expect. Checking fluid color involves pulling out the transmission dipstick and wiping it with a paper towel. The excess fluid on the towel can be compared to a transmission fluid color chart to indicate the issue. A transmission fluid change is recommended by service centers every two to three years, or 24,000 to 36,000 miles.
Pink, Red or Light Brown
Healthy transmission fluid is pink, bright red and dark red or even very light reddish-brown. Your transmission fluid is supposed to be a variant of these red colors. There are a variety of different brands of transmission fluid, which accounts for the variation in shade, but overall your fluid should have a reddish tint to it. Brand new transmission fluid will be lighter in color than fluid that has been in your car for a year or two.
Dark Brown or Black
Dark brown or black transmission fluid color means old or burnt transmission fluid from excessive wear. Burnt fluid may also have a burnt smell. If you have black or brown transmission fluid, it needs to be changed, and your transmission should be checked for problems to make sure it is not overheating and burning the fluid.
Healthy red fluid is translucent and viscosity is fluid and smooth. Dark, cloudy, creamy, milky or opaque transmission fluid is a sign of a problem with the transmission. Sometimes this is caused by coolant being forced into the transmission by a faulty radiator. It can also be caused by water or debris in the transmission. If the color of the transmission fluid is not clear/translucent with a red tint, you need to take your car to a transmission specialist and determine why. At the very least, your transmission fluid will need to be changed and transmission repair may be necessary.
Jen Davis has been writing since 2004. She has served as a newspaper reporter and her freelance articles have appeared in magazines such as "Horses Incorporated," "The Paisley Pony" and "Alabama Living." Davis earned her Bachelor of Arts in communication with a concentration in journalism from Berry College in Rome, Ga.