have a 04 2wd f150 xlt that has a shudder from the rear when I take off from a dead stop,it then goes away.On a recent highway trip,the whole truck shook for a couple minutes,then subsided.All tires are new stock size.Dealer says to check the rear brakes as to the shudder from a stop,haven't checked as to the highway thing,figured I would get better advice here,thanks.

 

Sounds like the transmission is slipping. You might want to change the fluid and filter, or at least make sure it's full.