Change transmission fluid how often?

[Thelt]

I have the V6 and the five speed auto. How often should the fluid and filter be changed? I have read it is only every 150k miles but that seems like a long time. The Grease Monkey tells me that is is sealed and only the dealer can change it. The local dealer tells me it should be changed every 30k miles but if that is right then why did they seal it?

 

[BrooklynBay]

That transmission isn't completely sealed. It has a filler plug, but no dipstick tube. There is a sticky thread on refilling the fluid in the 5R55W in the transmission section. If you tow, you will have to change the fluid more often. If you use full synthetic fluid, you won't have to replace the fluid as often as the Mercon V semi-synthetic fluid. Microfelt filters filter better than the regular screen style filters, so you will have to replace them more often. I would say that if you replace the fluid, and filter every 15-25k miles you will be OK.