How to Change Transmission Fluid

Tools Needed to Change Transmission Fluid

Before we get to the tools, let's discuss two different approaches to changing automatic transmission fluid (ATF). The first involves pumping out the old transmission fluid before adding the new. This approach has the advantage of removing more of the old fluid, even the ATF that collects in the nooks and crannies of the torque converter, but it's a bit more complicated. The second approach, known as the "drop-the-pan" method, doesn't require any pumping. As a result, it's much easier to do, although it leaves behind some of the old fluid to mix with the new ATF you add.

This article will explain the "drop-the-pan" method, which results ultimately in a partial fluid change. Don't let this discourage you. A partial fluid change still extends the life of your transmission. And you can always have your mechanic do a more thorough ATF flush at major service milestones.


Your mechanic most likely uses a transmission flusher, which completely flushes the cooler, torque converter, pump and lines without dropping the pan. Without access to such a high-end piece of equipment, you're going to need some tools and materials. The first thing you need is a transmission filter service kit. The service kit includes a transmission filter and a pan gasket. You're also going to need a catch pan and 3 to 6 quarts (3 to 6 liters) of automatic transmission fluid. All transmission fluid varies from car to car. Read the sidebar to learn more about the different types of ATF.

You can find the rest of the required tools in your garage. Here's what you'll need:

  • Socket wrenches
  • Screwdrivers
  • Mallet
  • Longneck funnel
  • Two old milk jugs
  • Jack stands or car ramp
  • Wheel chocks
  • Brake cleaner
  • Several clean shop rags

You'll use the milk jugs for measuring, not collecting. You can get by without them, but it's handy to know how much fluid gravity pulls from your transmission. When you go to add new ATF, you'll have a ballpark idea of how much fluid to add.

Collecting the right tools is just the beginning. Up next, we'll look at some necessary prep work before you start draining the fluid.