How to Change Automatic Transmission Fluid in a Toyota Corollaby Contributor
Many cars require that you change the automatic transmission fluid when it's warm or hot. However, many experts recommend that you change a Corolla's automatic transmission fluid when it's cold. Most Toyota Corolla cars require that you change the transmission fluid at least every 20,000 miles or 24 months depending on the year model of the car. Check the owner's manual to confirm the recommended maintenance schedule.
Remove the Old Transmission Fluid, Strainer and Gaskets
Park the car on level ground. You can raise it with ramps or jacks to gain easier access to the transmission. Ensure that you safely support the car.
Clean the outside of the oil pan and the surrounding areas thoroughly to remove all dirt and grease. This prevents contamination when you remove the pan. Remove the dipstick from the filler tube and replace it with a funnel.
Place a drain pan beneath the fluid pan, remove the drain plug with a socket wrench and allow the old transmission fluid to drain. If the drain plug has a metal gasket, you can clean and reuse it. Otherwise, if it has a fiber gasket, you need to discard it and replace it with a new one. Set the drain plug aside where it won't get dirty.
Loosen all but two of the fluid pan retaining bolts in a crisscross fashion. You will need a socket wrench for this step. When only two bolts are left, hold the pan with one hand while you remove the remaining bolts with the other. Be very careful when removing the pan, as some fluid will remain. Place the pan on a clean surface.
Remove the strainer by taking off the retaining bolts. Pay attention if some of these bolts are different lengths, so that you can replace them in their correct locations. Remove the strainer and discard the gasket. You may need to scrape remaining pieces of the gasket from the valve body.
Find the magnets on the bottom of the fluid pan, remove, and clean them. Don't be alarmed if you find metal shavings attached to the magnets. The magnets are there to collect this debris so that it doesn't clog up the delicate workings of the transmission.
Drain the rest of the transmission fluid from the pan and wipe the pan with a clean rag. Remove the old gasket from the pan and transmission. You may have to scrape off some of the material. Wash the pan and the drain plug thoroughly and allow them to air dry. Don't dry the pan with a rag, as lint can damage the transmission.
Replace the New Strainer Assembly, Gaskets and Fluid Pan
Install a new strainer assembly. Remember to replace all the bolts in the original locations.
Put the magnets in their original locations. Make sure that they don't interfere with any tubes.
Hold the fluid pan and gasket in position and hand tighten the retaining bolts in a crisscross fashion. Tighten them progressively to 45 to 60 inch pounds.
Replace the drain plug and gasket by hand. Then, tighten them with a socket wrench.
Add New Transmission Fluid
Find the type of transmission fluid you should buy written on the dipstick. You can also find this information in your owner's manual. You will likely find that the recommended transmission fluid is Dexron III.
Add the new automatic transmission fluid through the dipstick tube with the engine off. Some fluid will remain in the transmission, so add about half of the recommend dry refill amount to start. Check the level, add a little more fluid and check again until the fluid reaches the correct level on the dipstick.
Replace the dipstick, start the engine and let it idle for a few minutes without pressing the gas pedal. Shift your car through the gears and then back to Park.
Check the fluid level on the dipstick while the car is idling. If the dipstick indicates that the transmission needs more fluid, add a little more until the level reaches the full mark on the dipstick.
- Check the drain plug to ensure it isn't leaking any fluid.
- Don't overfill your transmission with too much fluid. When checking the level of transmission fluid, always pay careful attention to the cool and hot markings on the dipstick. If your engine is cold, the fluid should be in the "Cool" indicator range on the dipstick. If your engine is hot, the fluid should be in the "Hot" indicator range.