How to Change Transmission Fluid


How to Change Transmission Fluid

Automatic Transmission

Changing your transmission fluid is one of those things that often goes overlooked in most vehicles.  Most of us usually remember to change our engine oil regularly, or at least within a few hundred miles of going over the mileage on the reminder sticker on your windshield.  The reality is that there are more working fluids in your vehicle that require regular changing.  Any oil or fluid that is being pumped through mechanical systems is bound to become full of wear products and usually some dirt and grime as well.  All of these wear products and dirt floating around in your fluid, whether it’s in your power steering fluid or in your transmission fluid, will accelerate wear on that mechanical system.  Oils and transmission fluids are designed to lubricate the components they are operating in and around, but if you suspend small particles or dirt and worn metal in the fluids they often can do more harm than lubrication.

How to Change Transmission Fluid

Transmission Fluid Condition

Regularly changing your transmission fluid is the best way to make sure the dirt and metal particles that get into your transmission don’t have time to do any damage.  If you are meticulous about your vehicle’s maintenance then you hopefully know when the last time your transmission fluid was changed.  If you don’t remember when the last time your transmission fluid was changed, or you’ve purchased your vehicle used, it might be time for new transmission fluid.  Automatic transmission fluid is almost always red in color to help distinguish it from other oils in your vehicle like engine oil and gear oil.  As your automatic transmission fluid is used and collects wear products and dirt it will become a darker shade of red and if left too long can actually turn brown or black from all of the particles suspended in it.  You can pull your transmission fluid dip stick and wipe the fluid on a white paper towel to check the color and condition.

Moving on to how to change transmission fluid, it actually is not much different than changing your engine oil.  First, there should be a drain plug on the bottom of your transmission that needs to be removed in order to let the old fluid drain out.  You should consider doing this soon after you’ve driven the vehicle to make sure all the particles are still suspended in your transmission fluid and haven’t had time to settle out.  Once all the old transmission fluid has drained you should reinstall a new crush washer, if your drain plug has one, then reinstall the plug.  Remember, the transmission fluid pan is made of thin soft metal so don’t over tighten the drain plug.

If your transmission is equipped with a transmission fluid filter and you need to replace that as well, you will most likely have to remove the transmission fluid pan to access the filter.  This will require the removal of quite a few bolts and care taken to not damage the pan.

Once you drained the fluid and possibly replaced the filter you can refill your transmission with new fluid.  Most automatic transmissions do not have a fill hole so you may need to add the new fluid through the transmission fluid dip stick tube using a funnel with a small spout and a lot of patience.  Remember always add the manufacture’s recommended fluid type and amount.  Once you’ve added the new fluid start your vehicle and check the fluid level on the “cold” line on the dip stick.  Add more automatic transmission fluid if needed to bring the level up to “full”.

The last step in changing your transmission fluid is to add BlueDevil Transmission Sealer to your automatic transmission fluid.  Adding 1 oz of BlueDevil Transmission sealer per quart of transmission fluid will revitalize the seals in your transmission restoring shrunken or cracked seals stopping any current leaks and preventing future transmission fluid leaks.  BlueDevil Transmission Sealer is safe to say in your transmission fluid for the life of your transmission and won’t harm or clog it in any way.

BlueDevil Transmission Sealer is available at our partnering local auto parts stores so you can pick up a bottle when you get your transmission fluid.  Look for BlueDevil products at:

  • AutoZone
  • Advance Auto Parts
  • Bennett Auto Supply
  • CarQuest Auto parts
  • NAPA Auto Parts
  • O’Reilly Auto Parts
  • Pep Boys
  • Fast Track
  • Bumper to Bumper Auto Parts Specialists
  • S&E Quick Lube Distributer
  • DYK Automotive

You can also purchase BlueDevil Transmission Sealer directly from BlueDevil here.

Pictures courtesy of:
Automatic Transmission – “Tercel automatic transmission” by Hoikka1 – Own work. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons – Original Link

Transmission Fluid Condition – “fluidcondition_dipstick” by Licensed under Creatives Commons Attribution Share Alike 3.0 Original Link

BlueDevil Products can be found on or at AutoZone, Advance Auto Parts, O’Reilly Auto Parts, NAPA, and other major auto parts retailers.

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