As a semi-mechanically inclined person, I should probably know the answer to my own question, however I just thought I’d post this anyway. I have an 02 4x4 Screw with the 5.4L and auto tranny that has almost 30k miles. Just wondering what I should do or must do for maintenance at this point. Trans service? Flush the radiator? What about the diff fluid?

 

The transmission fluid and coolant should be replaced every 2 yrs/30,000 miles or so. The differential fluid is good for 100,000 miles.

Since Ford stopped installing torque converter drain plugs in 2000, you would only be able to drain the 5 qts that are in the pan if you do this yourself.

The coolant should absolutely be replaced every 2 years. If coolant stays in there too long, there can be major scaling problems and electolysis. The coolant can actually begin to conduct electricity and turn acidic, eating through the heater core. The heater core replacement involves about 12 hours labor to replace and quite a few people have had this electrolysis problem.

If you want, you can disconnect the transmission fluid return line at the radiator or cooler and run the engine to pump out the transmission fluid. My transmission has a TC drain plug so I've never had to use the pump method and couldn't really advise there.

You may want to look into whether or not you want to replace the coolant youself too. I've read a few 5.4L related TSBs about air becoming trapped in the cooling system when the coolant is replaced without a flushing machine.

Replace at 30,000 miles:

-Transmission fluid (not filter, the filter is good unless clogged)
-Coolant
-Air filter
-Fuel filter

 

Good stuff, AjR. I need to learn all of this.