My '86 has a drivetrain vibration that is getting worse.. Here's the kicker... I've got the angles for the diff. and transfer case identical. Got a driveshaft with new U-joints and balanced. The vibration occurs when there is NO load on the drivetrain. Coasting in neutral at speeds over 50 MPH or is not a fun experience. The weird thing is under load for both acceleration and deceleration, there is very little if any vibration. So, I'm thinking either my pinion bearing, or transfer case? what would be the highest suspect? thanks in advance for the help!