I'm trying to help a friend resolve her issue with her 08 expedition. When driving the truck will studder right at 44-45mhp every time. If going up a hill it will slam, if on flat ground it will studder and if going downhill it's less noticeable.

She took it to the dealership and had them exchange the fluid and they don't know what it could be.

The truck has 125k on it and is otherwise in great shape.

thanks,
shawn