BMW of Rockville
A BMW M Certified Dealer Certified Center

1450 Rockville Pike
Directions Rockville, MD 20852

  • Sales: 301-984-8989
  • Service: 240-283-8883
  • Parts: 240-283-8960


  • Monday 7:30 AM - 8:00 PM
  • Tuesday 7:30 AM - 8:00 PM
  • Wednesday 7:30 AM - 8:00 PM
  • Thursday 7:30 AM - 8:00 PM
  • Friday 7:30 AM - 8:00 PM
  • Saturday 8:00 AM - 6:00 PM
  • Sunday April 18 & 25 - Sales open 12pm-5pm

Like other vital automotive fluids, transmission fluid deteriorates over time. Hard use, such as frequent stop-and-go city driving and trailer towing will accelerate the deterioration too. The other issue is contamination.  As wear and tear occurs in a transmission, dirt-like particles become suspended in the fluid and this reduces its effectiveness.  The solution, of course, is to replace the old fluid with new.

So, when do you replace it? A lot of mechanics say it should be done at least every 50,000 miles. However, the manufacturer's maintenance schedule for many automatic transmissions doesn't call for fresh fluid until 100,000 miles or, with some Ford transmissions, even 150,000 miles.  It clearly depends on the car.

Do you have an older car and you unsure how long ago the transmission fluid was changed last?  Here's a quick method to check out its condition. Transmission fluid is usually red but when it gets old, it tends to turn darker in color. It may also acquire a burned odor that could indicate it needs to be changed or that the transmission is developing mechanical problems. Another indication it needs changing is that you can feel gritty dirt or other debris in the fluid when you put a drop between your fingers.

By the way, many repair shops use flush systems that force out the old fluid and pump in new fluid. Though that sounds good, some manufacturers say you shouldn't do that (Honda is one), so you need to know this before you agree to a flush. The automotive repair professionals at Priority One can give you guidance on this.