Exploring Automotive Electrical Faults

Here's What You Can Do If You Used The Wrong Transmission Fluid In Your Vehicle

It's easy to make mistakes when you're in a rush or if you don't know as much as you should about your vehicle. Grabbing a bottle of the wrong transmission fluid is a mistake can have costly consequences for your car or truck's transmission. Fortunately, there's a good chance you can undo this mistake if it's caught early on.

Stop What You're Doing

If you've realized you're using the wrong type of transmission fluid, stop what you're doing immediately. Don't start your vehicle and refrain from moving it unless it's absolutely necessary, since you don't want any more of the wrong fluid to circulate through the transmission pump and torque converter.

Look for Backwards Compatibility

In many cases, you might think you're using the wrong fluid only to discover that it's actually backwards compatible with the fluid your transmission officially calls for. So your next step is to see if the fluid you've used is actually backwards compatible. For example, using DEXTRON-VI offers backwards compatibility with transmissions that call for older versions of DEXTRON transmission fluid. Meanwhile, certain Japanese and European vehicles can handle multi-vehicle transmission fluid blends.

Drain and Flush Your Transmission

If the transmission fluid you've used isn't backwards compatible with your transmission, then you'll need to drain and flush it with the proper fluid your transmission calls for. This can possibly save your transmission if you haven't already driven the vehicle a significant distance. Here are some basic steps you can follow when it comes to draining and flushing your transmission:

  • Find your transmission's drain plug and place a catch pan underneath the plug.
  • Loosen the drain plug and wait for the fluid in the transmission pan to drain out. Some vehicles might not have a drain plug on the pan, so you'll have to carefully unbolt the pan partway and allow the fluid to drain out that way.
  • Completely remove the transmission pan and empty the remaining fluid. After checking the pan for metal debris, reinstall the pan and/or tighten the drain plug.
  • Refill the transmission with the correct amount of the correct transmission fluid. Afterwards, start the vehicle for a few minutes to let the fluid circulate throughout the transmission and then turn it off.
  • Repeat the above steps for draining and adding transmission fluid. You may need more than one flush depending on how much of the wrong fluid you've used.

When to Call on an Expert

If you used the wrong transmission fluid and your transmission refuses to upshift or downshift, or slips badly when in gear, then you may need to have it looked at by a seasoned mechanic. Depending on the severity of the damage, your mechanic may recommend a transmission rebuild or a completely new transmission altogether.

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