Reading Your Transmission Fluid Like A Pro

There's a lot you can tell about your car's automatic transmission simply by looking at the state of its fluid. Your transmission relies on its fluid for both lubrication and cooling, so it pays to know what kind of shape it's in. Here's how you can tell what's going on with your transmission.

How to Check the Fluid

Checking the transmission fluid is usually as easy as finding the right dipstick. Start the vehicle and remove the dipstick from its receptacle. After checking the fluid level, blot a small amount of fluid onto a white paper towel and observe the color of the fluid.

Can't find your vehicle's dipstick? Some modern vehicles don't have one because they're either "sealed for life" or require a complex machine to measure and meter transmission fluid levels. At this point, you'll want your mechanic to take a stab at checking the fluid.

What Your Fluid Says About Your Transmission

Here's what you can expect to see as you check the condition of your transmission fluid:

  • Bright red – In most cases, this is how your transmission fluid will look like straight out of the bottle.
  • Darker, cherry red – As the transmission fluid undergoes usage, it will eventually darken in color. This is completely normal as long as the fluid isn't completely worn out or burnt.
  • Very dark red or brownish – This usually indicates the end of the fluid's life cycle. By this time, you should plan for a transmission fluid change. Putting it off for any longer may result in the following condition:
  • Almost black or completely brown – Wait too long to change your transmission fluid and this may be the result. The fluid may also take on a burnt odor. In addition to fluid overuse, accelerated clutch pack wear, torque converter issues, or bad solenoids can also cause this condition.
  • Very light red or pinkish – Water or engine coolant has somehow found its way into the transmission, possibly through a worn or defective seal. Water can also find its way in through the transmission vent, especially during a flood or while driving through very deep puddles.
  • Tiny flecks of metal – At this point, your transmission is likely done for. Metal shavings found in your transmission fluid usually means serious internal wear.

To Replace or to Repair

Transmission fluid that remains within the bright red to dark red spectrum is not much to worry about. Nevertheless, you'll want to have your transmission fluid changed at least every 30,000 to 60,000 miles, regardless of whether it's still a healthy shade of red. If the transmission fluid is a very dark shade of red and it's not burnt, you should change it as soon as possible.

On the other hand, if your fluid is nearly black, nearly pink, or has metallic bits floating around, then it's time to save up for a complete transmission replacement. Changing the fluid at this point is more or less a crapshoot – your transmission could fail just miles afterward or several thousand miles later. Simply put, a replacement is the only way you'll get peace of mind. For assistance, talk to a professional like Integrity Transmission & Auto Service Center.