Vibration Woes, need help!.....Update As some of you know I’ve been fighting a drive line vibration problem for quite a time now with no success. I just got my Blazer back today from getting the 4:10s installed and I guess because the drive shaft is spinning faster, the vibration is worse. It’s almost non-existent below about 60mph but gets to the point where it will blur the mirrors by 70. Above that it really doesn’t get worse. At 63-65mph it’s enough to be really annoying. It doesn't go away when I put the truck in nuteral and coast either. I called the shop back and the guy who installed the gears (he has a GREAT reputation btw) said that it was an easy setup and he had a real good pattern the first time. Now that I’ve got all that out of the way, I need a plan of attack. Of course I’m planning on changing the U-joints out this weekend. When I crawled under the truck the driveshaft felt nice and tight. However, I did notice that the drive shaft angles weren’t the same. I have some 5-degree shims that I plan on installing, but I’ve forgotten which way to rotate the axle. Do I need to rotate the axle up or down? In other words, which way should the thick end of the shims go, front or rear? I’ve got to take a 400-mile trip the 23rd and I really don’t want to put up with a vibration for 5 hours each way. Of course any other ideas would be greatly appreciated! Lowered the transfer case tonight by moving the factory spacers from below the skid plate to between the plate and the frame.......MUCH better! I'll be putting 5 degree shims in Friday evening, will keep y'all posted.