03 Shudder at Take Off

[khodgens]

I'm going to look at an 03 EB w/4.6. The owner has stated that the transfer case and transmission was replaced recently by the ford dealer but there's a slight shudder when taking off. He was told the transfer case need to be flushed and new fluid added but couldn't guarantee this would solve the problem. I've done my searches here but can't quite seem to find this direct issue. Is it possible the torque converter needs the fluid replaced? Just thinking back to when I worked on old mustangs.

 

[khodgens]

Further info from the owner. The mechanic at the dealership told him that since the transfer case was replaced a little over a year ago that the transfer case needs to be flushed and that would most likely fix the shudder. Since I've not run into this before on later models does this make sense. I'm just trying to gain as much knowledge as I can before I drive 2 hours to go see it.
Thanks