When should I change transmission fluid 2007 Expedition

[eddyinc]

I have a 2007 Expedition Limited edition 4x4. I'm the only owner, bought it brand new, and now it has 38K miles. At what milage should I replace the transmission fluid?

Thank you

Eddy

 

[hautevue]

I have an 08 Expy 4wd and my tranny is sealed--when I asked about changing the fluid, he said it never needs to be done since it's sealed. I was skeptical, but he showed me that there is no dipstick to check the fluid level..

 

[ludlow]

I bought an 07 used last year with ~30k miles on it. I had the fluid changed shortly after I bought it. Since I tow a camper and a boat with it I plan on changing the fluid every 30k per the manual under the severe driving conditions.