One important part of auto service is your transmission fluid. Why? Well if you don’t pay attention to this one little detail, it can come back to haunt you later on. So, with that in mind, here is some information.
Transmission Fluid: What It is and When To Change It

What is transmission fluid? From WIKIPEDIA.ORG “Automatic transmission fluid (ATF) is the fluid used in vehicles with self shifting or automatic transmissions. It is typically colored red or green to distinguish it from motor oil and other fluids in the vehicle. On most vehicles its level is checked by a dipstick while the engine is running. The fluid is optimized for the special requirements of a transmission, such as valve operation, brake band friction and the torque converter as well as gear lubrication. Despite popular parlance, ATF is not an oil.” SOURCE ARTICLE
Interestingly enough, manual transmissions also use transmission fluid but their fluids are largely composed of motor oil and a couple of other lubricants. As to what transmission fluid looks like, it is a bright red in color if it is healthy, and a dark, almost black color if it needs to be replaced. Next, we’ll cover how often to replace your transmission fluid.
How Often Should I Replace My Transmission Fluid?
Your car or truck’s owner’s manual is the definitive authority on this subject. So check that first, however, know that a good operating principle is to replace your transmission fluid every 30,000 miles. This will help to keep your transmission shifting smoothly and help you to avoid damage to your transmission’s gears.
One key thing to remember is that unlike motor oil, transmission fluid doesn’t dissipate, so if your fluid is low, you may have a leak somewhere. If that is the case, get your car or truck into a transmission repair shop as soon as you can.
Trail Transmission
11240 East Apache Trail
Apache Junction, AZ 85120-3529
(480) 986-7367