However, if you're determined to do it yourself, here's a general overview. This is not a complete, step-by-step guide and should not be considered a substitute for a proper workshop manual specific to your vehicle. You will need a workshop manual for detailed instructions and torque specifications.
What you'll need:
* New transmission fluid: Consult your owner's manual for the correct type and amount. Use only the recommended fluid. The wrong fluid can severely damage your transmission.
* Transmission fluid pan gasket: This will almost certainly need replacing.
* New transmission filter: Highly recommended.
* Drain pan: Large enough to hold several quarts of fluid.
* Socket wrench set: Including the correct size for the drain plug and fill plug.
* Torque wrench: Essential to avoid over-tightening the drain and fill plugs.
* Jack and jack stands: Safety First! Never work under a vehicle supported only by a jack.
* Funnel: To add new fluid.
* Wrench or socket for the transmission pan bolts: The pan bolts can be tricky to reach.
* Gloves: To keep your hands clean.
* Rags or shop towels: For cleanup.
* Shop manual for a 1999 Ford Expedition: Absolutely crucial for torque specs, fluid capacity, and detailed procedure.
General Steps (Consult your shop manual for specifics!):
1. Warm up the transmission: Drive the Expedition for 10-15 minutes to warm the fluid. This makes it flow more easily.
2. Safety First: Secure the Expedition on level ground using jack stands. Never work under a vehicle supported only by a jack.
3. Locate the transmission pan: This is usually located on the bottom of the transmission.
4. Drain the fluid: Carefully position your drain pan and loosen (then remove) the transmission drain plug. Let the fluid drain completely. This might take some time.
5. Remove the transmission pan: Once drained, remove the transmission pan bolts carefully. The pan may contain some remaining fluid, so be prepared.
6. Replace the filter and gasket: Install the new filter and gasket. Make sure the gasket is properly seated.
7. Reinstall the transmission pan: Carefully reinstall the transmission pan and tighten the bolts to the manufacturer's specified torque. Use the torque wrench!
8. Locate the transmission fill plug: It's usually on the side of the transmission.
9. Add new fluid: Use a funnel to add new fluid through the fill tube until it starts to overflow from the fill tube. This is crucial because you're not just replacing the fluid in the pan; you're also replacing fluid in the torque converter. The quantity needed will be specified in your manual.
10. Check the fluid level: After filling, start the engine, let it run for a few minutes, and then check the fluid level again (often involves removing the fill plug to check fluid level on the dipstick. Consult your manual). Add more fluid if necessary to reach the correct level.
11. Reinstall the fill plug: Tighten it to the correct torque specification.
12. Lower the vehicle: Carefully lower the vehicle from the jack stands.
13. Test drive: Test drive the Expedition to ensure the transmission is shifting smoothly.
Important Considerations:
* Fluid Capacity: The exact amount of transmission fluid needed will vary depending on the type of transmission in your 1999 Ford Expedition. Your shop manual will give the correct amount. Adding too much or too little fluid can damage the transmission.
* Torque Specifications: Using a torque wrench is absolutely essential to avoid stripping the threads on the drain and fill plugs. Incorrect torque can lead to leaks and damage.
* Transmission Type: The process might vary slightly depending on whether your Expedition has a 4R70W or another transmission type. Your manual will clarify this.
Again, this is a simplified overview. You absolutely need a repair manual specific to your 1999 Ford Expedition to perform this task safely and correctly. If you are not comfortable with auto repair, it's strongly recommended to have a qualified mechanic perform this service. Incorrectly performing a transmission fluid change can lead to significant damage and expensive repairs.
