Vibration coming from seat, steering, gas and brakes

What is your question?

Have extreme vibration 20 km + and would come and go. Main on set was from hitting a bumb on a highway or even the regular street. Had the transfer case replaced and everything was perfect for a mater of two weeks and it came back. Now the drive shafts is being balanced but still no idea on what has caused this. And I need a pare of 26 spline hubs for this truck because im and the driveline guys I've been to think my lines have a leak or even worse water in the lines does anyone have any ideas?