How to change transmission fluid: 10 steps

When it comes to DIY car maintenance, oil changes get all the attention. But changing your transmission fluid is just as important. People often ask, “Is changing transmission fluid easy?” or “Should I change my transmission fluid myself?” 

If you’re reading this page, you’re at least thinking about it. So here’s a little extra incentive: having a car dealer or auto shop do it will set you back up to $250. We’re sure you could find a better use for that kind of cash. If you can spare about an hour, changing your transmission fluid is something you can do yourself — and it’s worth the effort.

Let’s go through the simple steps you need to change the transmission fluid yourself. Before we get started, let’s tackle some common questions. 

Is transmission fluid the same as oil?

While both are oils and lubricants, engine oil is primarily for the internal combustion engine and transmission fluid is for the steering system. They should never be used interchangeably.

What happens if you don't change transmission fluid?

Over time, transmission fluid becomes dirty and less effective. It won’t lubricate the transmission as well, leading to increased heat, friction and engine wear.

10 steps to change transmission fluid 

Once you have all your tools and supplies, you’re ready to get started. So let’s do this.
 

Step 1: Get your car ready and check the transmission fluid

Before you raise your vehicle, start the engine and let it run until it’s warm. For safety, park on a level surface and set the parking brake. Find the transmission fluid dipstick (it’s usually red or orange), pull it out, wipe it with a clean rag and reinsert it. Pull the dipstick again and check the level and color. Dirty fluid will be dark red or brown.

Step 2: Raise your car

Make sure you turn off the engine and let it cool for five to ten minutes. You’ll need to get access from underneath. This is where the car jacks and jack stands or ramps come into play. Never rely on just a jack to hold up your car when you’re going to be working underneath.

Step 3: Locate the transmission fluid pan and check for a drain plug

For most front-wheel or four-wheel drive vehicles, you’ll find the pan on the left or right side of the engine. On rear-wheel-drive vehicles, it’s typically located beneath the center console area. 

Next, check to see if your fluid pan has a drain plug. If your car does not have a drain plug (and unfortunately, most do not), you’ll need to take off the entire transmission pan. But read Step 4 before doing so. 

Step 4: Get ready to drain the transmission fluid 

Set up your drain pan to catch the fluid. Make sure that it’s wide enough and in the right spot to avoid a messy spill. Put on your gloves and safety goggles. When you’re sure that your drain pan is lined up, you can prepare to remove the plug or the entire fluid pan.
 

To remove the plug: loosen, but hold in place.

To remove the entire fluid pan: remove all the bolts (usually 6 – 8 of them)

Be careful, once you fully release the plug or remove the pan, the fluid will start pouring quickly. Letthe old oil drain until it has slowed to a drip. Once the fluid has finished draining, wipe down yourdrain plug and/or the pan and reattach.

Step 5: Check the old fluid for debris

It’s not unusual to find small metal shavings in the old transmission fluid. But if you see metal shards that are large enough to pick up, you have a problem. You’ll want to stop using the vehicle and have a mechanic inspect the transmission for damage.

Step 6: Inspect the transmission fluid filter

In most situations, the filter does not need to be replaced. But you’ll want to inspect it for any cracks or leaks. The filter will be attached to the transmission with some clips, bolts or the filter’s O-ring gasket. 

If you do need to replace the filter, simply remove it and wipe down the area where the filter was attached. Before you attach the new filter, you’ll need to quickly lubricate the O-ring gasket. Dip your gloved index finger in some of your new transmission fluid and apply a light coating. Then install the new filter and reattach the bolt. Make sure it’s secure, but don’t overtighten.

Step 7: Reattach the transmission fluid pan

Skip this step if you only had to remove the drain plug. Make sure the filter is properly attached. Wipe down the pan and bolts. Then line up the pan and hand tighten the bolts. Next, use your socket wrench to fully tighten. Avoid over tightening so you don’t damage the pan or the bolts.

If your owner’s manual does not have a recommended torque, you’ll just want the bolts to be screwdriver tight. 

Step 8: Refill with the new transmission fluid

If your car was elevated, lower it back to flat ground. Open your hood and locate the transmission fluid port. Insert your funnel and slowly fill with the proper amount of transmission fluid as indicated in your owner’s manual. Wipe off any drips.

Step 9: Inspect for leaks, then check the fluid level

Start your engine and let it run for a few minutes. This will help the new fluid circulate. Check underneath your car to make sure there are no leaks.

Then open your hood to check the fluid level. Remove the dipstick and wipe away the fluid with a rag. Reinsert the dipstick, then remove again to check the level. It should reach the “full” mark at the tip. If not, slowly add a little more fluid and recheck.

Step 10: Properly dispose of that old transmission fluid

Never pour the old fluid down the drain or into a drainage sewer. Instead, you’ll want to pour it into a container with a lid. Many auto parts stores will accept and recycle used transmission fluid. You can also contact a local recycling facility or your town to see if they will accept it.

That’s it! 

You just saved yourself up to $250. And like most things, changing your transmission fluid gets easier every time you do it. You’ll be a pro in no time.