How to Change Transmission Fluid
Transmission fluid should be changed every 30,000 miles, based on the vehicle manufacturer's recommendations, or following the time interval listed in your owner’s manual.
It is recommended to leave the transmission fluid change to your trusted mechanic. Or you can learn to do it yourself and save money on it. The following steps will show you how to replace the transmission fluid in a few hours.
1. Check the fluid level using the dipstick.
The transmission fluid dipstick is usually red-handled. It should be labeled clearly and easy to access on most cars, close to the oil dipstick. Dipsticks have a hot and cold reading.
If you didn’t run your vehicle for about an hour and you do not live in an extremely hot climate refer to the Cold Reading for proper levels. If the level is low, but the fluid looks clean, then you just need to top it off. If you notice the fluid’s color change, you need to change it. If it is time to replace the transmission fluid according to the time interval shown in the owner’s manual, you should change it anyway, even if the fluid looks good.
2. Prepare the vehicle.
Park your car on level ground and set the emergency brake. Then place wheel chocks behind the front wheels. Lift and support the vehicle with jack stands.
3. Locate the transmission fluid pan.
Usually, the pan is attached to the bottom of the transmission. For front-wheel drive vehicles, the transmission is typically situated left-to-right under the engine bay. For rear-wheeled cars, the transmission usually hangs under the center console area, facing front to rear. In some vehicles, you’ll be able to grain the transmission fluid without removing the transmission pan at all, only by removing a drain plug in the center of the pan. But on some vehicles, you have to remove the whole transmission pan by unscrewing bolts. It is better to remove the entire pan in order to examine the fluid filter, gaskets, and other components just in case.
4. Drain the transmission fluid.
To drain the fluid, either unscrew the drain bolt or remove the pan unscrewing the two upper-most bolts halfway, then the other bolts all the way. Don’t forget to place a pan under it to catch the old transmission fluid.
5. Examine the fluid that drains out.
Most automatic transmission pans have a magnet inside to collect metal shavings that have been produced by worn moving parts. Remove these shavings along with the remaining fluid in the pan. Metal shavings are normal and represent the typical wear and tear of the gears. If you see any large or odd-shaped chunks contact a certified mechanic to check your transmission to ensure that there are no serious damages. About 50 percent of the fluid will remain in the transmission when you drain it. To remove all the fluid, you must flush the transmission entirely.
6. Inspect the transmission fluid filter and gaskets.
When changing the transmission fluid, it's good as well to inspect the filter and gaskets and replace them if necessary. They can be cracked or leaky. After all, reinstall the transmission drain plug and tighten it until it’s snug. Don't over tighten the bolts.
7. Replace the transmission fluid.
Remove the jack stands and lower the vehicle. Using a small funnel, pour the transmission fluid into the dipstick. Consult the vehicle repair manual for the correct type and amount of fluid to add. Make sure to use the type recommended by the car manufacturer. Check your owner’s manual to add the right kind of fluid.
8. Start the vehicle and check the transmission fluid level.
Start the car and let it idle until it reaches operating temperature. With the engine still running, check the fluid level. If the level is low, add more fluid. Repeat until the transmission fluid is at the right level. Avoid overfilling. Some transmissions require the fluid to be checked in neutral and others in the park. The wrong amount of fluid will be added if not in the correct position. Check the owner’s manual for the correct position and the right fluid level.
9. Remove the wheel chocks.
10. Drive the vehicle and recheck the fluid level.
Drive the car for the next couple of days, then recheck the fluid level, adding as needed. Also, it is good to do to check for leaks.