How to Change Transmission Fluid and Filter

Changing the fluids in your vehicle at the proper intervals is one of the best ways to keep your vehicle running well. Fluid changes are well within the realm of the do-it-yourself mechanic and, with a little patience and planning, you can save money on regular service and avoid costly repairs in the future. Changing a transmission's fluid and filter is a little more involved than simply changing your oil, but no more difficult. If you can change your engines oil and filter, you can change your transmission's fluid and filter.

Difficulty: Moderate
Instructions

Things You'll Need
Floor jack
Jack stands
Drain pan
3/8-inch drive socket set
Flat head screwdriver
Philips head screwdriver
New gasket
New filter
Transmission fluid

1.Allow the vehicle to cool completely before beginning work. Apply the parking brake. Raise the vehicle on one side with the floor jack. Place a jack stand under the vehicle at a solid support point such as a frame rail. Slowly lower the floor jack so the vehicle rests on the jack stand. Repeat for the other side of the vehicle.

2. Place the drain pan under the transmission and remove the drain plug from the transmission pan using the appropriately sized socket wrench, and allow the fluid to drain completely. After it has stopped draining, replace the drain plug in the transmission pan and tighten it securely.

3. Remove the bolts from the transmission pan using the socket wrench.

4. Carefully pry the pan away from the transmission using the flat head screwdriver. The pan will still have some fluid inside, so use caution not to spill it and set it to the side.

5. Clean the gasket surface of the transmission where the pan was removed. Remove all traces of gasket material and wipe it clean with a clean cloth.

6. Pour any remaining fluid in the transmission pan into the drain pan and clean the pan thoroughly. Wipe all pan surfaces dry with a clean cloth.

7. Remove the filter from the transmission valve body using the socket set or screwdriver depending upon the model, being careful not to damage any parts of the valve body, and throw it away.

8. Install the new filter and its seal onto the valve body, insert its bolts, and tighten it down firmly with the socket wrench. Some filters have the seal already installed on the filter, simplifying the process.

9. Install the new pan gasket onto the transmission pan. Put the pan in place against the transmission, and install the pan bolts. Tighten each bolt a little at a time in succession, working your way around the pan. Finish by tightening them all down to the manufacturer's listed torque specifications.

10. Lower the vehicle from the jack stands and add transmission fluid. Four quarts is typically a good quantity to start with, but check with your model's owners' manual to make sure you won't overfill the transmission at that level.

11. Start the vehicle and let it idle. Holding the brake pedal down, move the gear selector through the gears then back into the park position and allow the vehicle to idle for two more minutes in park.

12. Turn off the vehicle and check the transmission fluid level. It will be low, so add fluid until it reaches the correct levels on the dipstick. Do not overfill. Check under the vehicle for leaks after a short trip, and check the fluid again after the vehicle has reached full operating temperature, adding fluid if necessary.