Rough Shake
 

Hey
I have a 2005 frontier and recently it has developed a serious shake at any speed. I use it for work and I drive on gravel roads, muddy roads, and trails often for work. I always spray out my wheels and don't rip around too much. I haven't hit or ran anything over with it that may have caused something to break....
Any insight into what maybe causing this serious vibration/shake?
thanks!

Bad U-joint? Double and triple check for mud accumulation in the wheels, then try and have the wheels balanced.