[Airjer_]

If it pulls hard it is usually a tire issue (radial pull) if it is a light pull it is usually an alignment issue. Swapping side to side is a good tip. Once you get the pulll taken care of I wouldn't be surprised if the vibration in 4WD is still an issue. Are all 4 tires about the same tread depth? Or do you have two that are brand new and two that are just about worn out. Extreme differences in tread depth will cause just enough rotational difference between the front and rear to cause the 4WD to bind up and "hop".