Look for the transmission fluid dipstick, which is usually red-handled. It should be labeled clearly and easy to access on most cars, close to the oil dipstick. [3] X Research source Dipsticks list a hot and cold reading. If your engine has not been run in about an hour and you do not live in an extremely hot climate refer to the Cold Reading for proper levels. If your levels are low, but the fluid looks clean, you might just top off the system. [4] X Expert Source Ed BeeryAutomotive Specialist Expert Interview. 19 November 2021. If the fluid looks discolored or sludgy, you need to change it. If you’re at the mileage marker that requires you to change your transmission fluid, you might just elect to change it anyway, even if the fluid looks good.
Always park on a flat, even surface when you’re working under the car and use support stands, chucks, or other acceptable bracing to ensure safety should a jack fail or the vehicle attempt to roll off ramps. [5] X Research source
Examine the pan. In most vehicles, you’ll be able to drain the transmission fluid by removing a drain plug in the center of the pan and letting the fluid drain out into a receptacle. On some vehicles, however, you might have to remove the transmission pan entirely. The fluid pan will have multiple smaller bolts around the border to hold the pan to the transmission, which you can unscrew and pull the pan free. If you want to inspect the fluid filter, gaskets, or any other components, you may want to remove the pan anyway to examine the assembly more thoroughly.
If your transmission lacks a drain plug, draining the fluid is potentially a very messy operation. Because the fluid will drain around the pan (rather than through a drain plug hole), you will need a collection pan at least as wide as the transmission pan itself if you don’t want to make a mess.
If the transmission pan has a drain plug, remove the plug to drain the fluid into a collection pan. Use a pan that can contain up to ten quarts of transmission fluid, although that much probably will not drain out. If you need to remove the entire transmission fluid pan, unscrew the two upper-most bolts halfway, then unscrew the other bolts all the way. As soon as the last bolt is completely unscrewed, the pan may drop a bit and fluid will begin draining. You may also have to pull it loose using some force.
About 50 percent of the fluid will remain in the transmission when you drain it. To remove all the fluid, including the fluid in the torque converter, you must flush the transmission completely, a process that is usually part of a more comprehensive maintenance routine.
If you do this, or if you elect not to, replace the plug and the pan assembly, tightening with a socket or torque wrench. Don’t over tighten the bolts.
On most vehicles, you’ll add the transmission fluid through the port from which you removed the dipstick. The new fluid goes directly into this spout, in most cases. You will need to use a funnel. Pour in a little less fluid than drained out so as not to overfill. You can find out the proper amounts in your owner’s manual. [9] X Research source
Most auto parts stores and body shops will have fluid recycling programs that allow you to drop off your motor oils, transmission fluids, and other vehicle fluids that you collect when maintaining your vehicle. Find a drop-off site in your area.
