2002 Jeep WJ overland, Quadra drive, 247J transfer case, 4.7 HO.
After roughly 20 minutes of driving the Jeep starts to buck forward and backward relentlessly, even if I throw it in neutral it continues to buck, I have to stop driving, if I shut it down and come back to it in an hour or so, it will drive perfect, again, for another 20ish minutes then start violently bucking front and back not side to side at all.