Steering Wheel Shimmy
 

I've seen a lot of posts similar to this on the forums but want to get some input. I've got an 07 XLT SCREW 4x4 92k all stock, new-ish BCT (who dat?) front tires. The steering wheel starts to shimmy around 50-55 and gets worse up to 65 then tapers off slightly. I just bought the truck used and am taking it to the dealer next Thurs to take a look at the cause of the shimmy and have the tranny flushed and filter changed.
(Cant find any service records on Ford owners' site, no idea what's been done.)

Anything I should have them specifically them take a look at that could causing the shimmy, beside balance/alignment/tires?

Thank for the help!