Re: Drive shaft vibration?
OK, It's my understanding that unless you've already got the CV joint setup, you still have to check the angles even with the transfer case drop. My understanding is that the drop mostly changes the transfer case output shaft angle (not the front of the drivetrain, like the engine). Ideally, not only should the transfer case point down ata good angle, but the rear diff should point up at an equal angle. This is because the action of the "bent" u-joint causes the rotational speed of the shaft to vary as it turns a full circle, and it requires an equal "bend" in the other u-joint to cancel that factor out and turn the diff pinion at an even rotational speed. the diff drop will lower the angle, but if your diff angle was matched to the transfer case before the drop, the diff angle might actually be too high.
If you've had the drop for a while with little or no vibration, and it's just started with the u-joint replaced, then it's probably not the above scenario. Maybe check the u-joint caps, that they're not tapped down too tight. You want the u-joint to be able to move easily. If you've got zerk fittings on them, grease 'em. Maybe that might cause vibration, I don't know, I know it'll wear on your u-joints at any rate. Check the u-bolts (or sissy strap 'n bolts if you've got 'em, seems like I read that you should swap for u-bolts if you can), make sure they're tight but not pinching the caps. Those are some of the things I'd do first, before messin' with the transfer case. Anybody, correct me if I'm wrong, I'm still learning this stuff too.