How to Change Transmission Fluid

transmission

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Doing a transmission fluid change is a DIY maintenance job that can save you money

A transmission fluid change might be a job you leave up to your trusted mechanic. Or you can learn to do it yourself in a few hours and save money in the process. If you're feeling like DIYing the job, we're here to help. Let's get you started.

When to change transmission fluid

Transmission fluid should be changed every 30,000 miles, or based on the vehicle manufacturer's recommendations. An automatic transmission that shifts roughly, slips or is noisy could also benefit from a transmission fluid change.

Vehicles that see severe usage such as towing or heavy hauling will need transmission fluid changes at an earlier interval; fluid that is darker than magenta and has a burnt-toast smell should definitely be changed.

How transmission fluid works

Your vehicle's fluids perform two vital functions: lubrication and cleaning. As fluid circulates through various parts, it gathers and traps dirt and contaminants that can build up as the parts wear. Because of this, nothing adds longevity to a vehicle's life like regular fluid and filter changes. Automatic transmission fluid (ATF) is crucial to the operation of your automatic transmission. Different vehicles require specific types of ATF, so be sure to check your owner's manual for details before changing transmission fluids.

Vehicle System
Fluids & Filters
Skill Level
Intermediate

This is a project that needs some know-how

Time to Complete
1-2 hours
  1. Prepare your work area for drips and spills. Wear gloves and safety goggles.

  2. Transmission fluid drains better when slightly warmed, so let your vehicle idle for a few minutes. Then, turn off your engine, and raise and secure the vehicle on jacks.

  3. Most vehicles don't have a transmission fluid drain plug and instead require the transmission pan to be removed. Place a drip pan under your transmission and slowly remove the bolts on one side of the transmission pan. Watch for hot surfaces and remember this will be a messy job.

  4. Starting closest to the bolts first removed, remove the rest of the bolts. The idea is to get the pan to tilt and drain from one side.

  5. Remove the pan and scrape off any old gasket material from mating surfaces. Then remove the old filter and O-ring. Prepare for more fluid! Take note of the filter mounting location.

  6. Automatic transmission filter kits usually contain a gasket and O-ring for filter sealing. Place the new filter onto the transmission in the same location as the old one. Make sure all surfaces are free of debris and all fluid passages line up correctly.

  7. After cleaning any debris out of the pan, install the new gasket using a thin film of oil-based grease to keep it attached. Keep an eye out for metal shavings or plastic particles, which can indicate transmission problems. Do not use adhesives.

  8. Lift the pan up onto the transmission and install bolts, finger-tight. Use a torque wrench and tighten the bolts to manufacturer's specifications in a criss-cross pattern. Tightening bolts in the right sequence is essential for a properly-seated gasket.

  9. Lift the pan up onto the transmission and install bolts, finger-tight. Use a torque wrench and tighten the bolts to manufacturer's specifications in a criss-cross pattern. Tightening bolts in the right sequence is essential for a properly-seated gasket.

  10. Safely lower the vehicle.

  11. Safely lower the vehicle.

  12. Using the long funnel, fill your transmission with the recommended type and amount of fluid.

  13. Start the vehicle to check for leaks, cycle through all the gears, then check fluid level when the vehicle is warm and in neutral, using the dip stick. Be sure to check for leaks periodically for the next couple of days.

  14. Pro Tip

    Always check your automatic transmission fluid with the parking brake securely applied and follow your owner’s manual instructions.

Last updated June 26, 2017

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