When do I need to service my 03 Expedtion's transmission? It has the 4.6l and the transmission code is U. The owners manual doesn't mention when this transmission fluid needs changing. Only to check with the dealer. I don't trust dealers.

 

most people service their tranny every 20k - 30k miles. I split the diff and do it every 25k. Pretty standard for all auto tranny's.

 

Just did it with new Amalie fluid and seems like it's a bit tighter in the converter and shifts nice. Worth it.. Jer

 

I'd say every 30K. Fluid and filters are cheap. Overhauls or reman units aren't.

 

i changed the auto tranny fluid & transfer case fluid @30K