After posting I went out to the truck and checked the oil levels in my front and rear differentials. The rear was almost dry and took a whole quart to fill. The front was very low and took about half a quart. Drove the truck today for about I'd say 30 miles and I haven't experienced the vibration yet. Yesterday I experienced it alot, and it seem to get more frequent. I'll let everyone know if it works, but so far it seems to have improved.