Brought it in to have the transmission checked - thought I read on the Carfax that the transmission had been flushed/filter changed before, but the shop told me that it's the original (150k mile) fluid. Glad I had it checked before I just dropped the pan and changed the filter.
Got a Vib 45-50 again. Shop told me to take it back to the guy who put the lift in to check the pinion angle and to take the drive shaft in to check the balance.
Well, the drive shaft has about 3k miles on it since I got it balanced and new U-Joints. Guess I'm going to have to figure out that pinion angle since I'm the lift guy.