Regular fluid change is a sure-fire way to prolong the life of your favorite car or truck. Automatic transmission fluid provides a perfect lesson of what could go wrong if you get lazy or forget to change it out every 30,000 miles of 30 months.
How do you change the automatic transmission fluid and filter in your vehicle?
YouTube grease monkey ChrisFix lays it out in these five basic steps:
- Elevate the vehicle and drop the transmission pan
- Replace the filter
- Replace the transmission pan gasket
- Install the pan
- Add the fluid
It can get a bit messy, but no worries – ChrisFix helps you stay on top of it in this complete guide. So, pop that hood, and let’s get rolling.
Changing Versus Flushing Automatic Transmission Fluid
To illustrate the entire process of changing your automatic transmission fluid and filter, ChrisFix uses a 2001 Mazda pickup truck. It has the same chassis as lots of Mazdas and Fords. However, the process is pretty much the same with most makes and models.
There’s one very important thing to note before following this guide. What you’ll be doing here is a transmission “change” and not a transmission “flush.” There’s a big difference!
With a “flush,” you typically use a machine to pump out all the old icky fluid and replace it with new fluid. This gets rid of any accumulated dirt and debris before replacing the fluid. But you don’t remove the drain pan, so there’s no need to replace the filter.
With a transmission fluid “change,” you’ll dump only the old fluid, drop the transmission pan, and replace the filter. It can get messy pretty quickly because a lot of transmission pans don’t have plugs.
You’ll take out the entire pan and put in a new filter.
Never flush the fluid if it’s black, has a burnt smell, or glitters with metallic specks. That means your transmission is likely damaged, so flushing could make it slip. New fluid is bright pink, so look for at least a pinkish or orangish hue.
If you’re confused about which one to do, just thumb through the owner’s manual for your specific vehicle.
Gather Tools, Fluid and Filter
Before popping on your ever-ready safety glasses and gloves, line up all the tools you need to change the automatic transmission fluid. Here’s what you’ll need to do the job right:
- 10-millimeter, 13 millimeter ratchet wrenches, plus an extension
- Torque wrench
- Scraper and abrasive pad to clean the gasket
- Funnel and brake clean
- Towel, catch can for fluids, and tarp to protect garage floor or driveway
Next, use your owner’s manual to choose the correct transmission fluid, which is crucial for protecting the transmission. Buy a new filter, which comes with the new sealing gasket for the transmission pan.
Step 1: Drop the Transmission Pan
Let your car idle for a few minutes so the transmission will drain better. Use a jack stand or ramps to safely lift your automobile high enough to drain the fluid and reach the transmission pan.
Chock off the wheels and position the catch can, then locate the transmission pan. Use a ratchet to remove only the rear bolts from the pan. This lets the pan hang at an angle for a controlled leak to drain the fluid into the drain pan.
Next, remove the side bolts. Use a universal joint extension for the hard-to-reach bolt behind the catalytic converter. Loosen the front side bolt and control the spill. Now you can support the transmission pan and slide that baby right out.
Step 2: Replace the Filter
Do away with the old transmission filter and O-ring. It’s easy to remove the single bolt, and it’ll pop right out. While you’re in there, it doesn’t hurt to snug up the bolts holding the transmission valve body up against the transmission.
Finally, lube up the O-rings, install the new filter, and you’re good to go. Hot Tip: Always hand-tighten the filter bolt first to keep it from cross-threading.
Step 3: Replace the Transmission Pan Gasket
First, remove the old transmission pan gasket. If necessary, use a plastic scraper to dislodge it. A metal one might cause some scratching, which could lead to fluid leaks. If your pan has a magnet, use brake cleaner to remove any accumulated metal debris.
Clean up any dirt and grime, and then use abrasive pads to spiff up the mating surface. Now, you’ll attach the new gasket using oil-soluble grease. If you happen to have a cork or paper gasket, you might want to use gasket adhesive or sealant to prevent leaks.
Step 4: Install the New Transmission Pan
It’s generally okay to reuse the bolts, but make sure the threads are clean and free from gasket adhesive. If you’d like, check your vehicle’s service manual for recommendations on reusing those bolts.
Torque the pan bolts to about 10 to 15 pounds per foot, starting at the center and continuing in a criss-cross pattern. It may help to use a universal joint socket for hard-to-reach bolts. You’ve now installed the new transmission pan.
Step 5: Add the Automatic Transmission Fluid
The final step is a piece of cake. Ease your car or truck back down again, and fill ‘er up with transmission fluid. Slide it off the ramp and double-check your work.
Start the engine, and let the transmission warm up for two to three minutes. The fluid will circulate, but you still need to let it idle a bit. Then turn off the engine and look for leaks. Crank her up again, shift through all the gears, and check the fluid levels with a dipstick.
If everything looks good, you’ve accomplished your goal and changed the transmission fluid like a real pro! Your vehicle is a vital part of daily life, so stay in tune with the automotive world through the folks at Vehicle History.
