Ok, here's a question that has to do with the dreaded driveline vibration! I went from a 4" lift to a 6" lift last December. This was done with 6" Superlift Superride front springs and an ORD 4" shackle flip + 2.5" Superrides out back. At the same I swapped in a 14bff with a Detroit Locker rear and converted to 8 lug 10 bolt with ARB up front. Upon driving the thing for the first time, it vibrated horribly! So, we lowered the t-case by turning the stock spacers over underneath the frame. That helped a bit, but didn't get rid of the vibes. Then I installed some 3 degree shims under the rear springs, that again helped, but didn't stop the vibes. It doesn't vibrate very bad except when in that "zone" between on the gas and off the gas, you know, when you let off suddenly and then as you get back into the throttle. So, then I tried some 4 degree shims, same effect - a little better but still no cigar. So, last night I swapped in some 6 degree shims - this brought the angles of the rear diff and t-case output to 1 degree up (rear axle) and 1 degree down (t-case) - keep in mind that this was done on an unlevel driveway so my main concern is that the angles are damn close to one another, that is the key! So, I go drive it and it is still doing the vibe thing when off the gas/on the gas. So, I am wondering, do any of you guys with Detroits have a similar vibration? Is this something that I should just put up with? I have broken u-joints in the past at speed and I don't want any more of that, so that is why I keep trying to fix the vibes. Thanks for any ideas/help. I am getting ready to just say to hell with it all and get a CV shaft and turn the axle up, but I would much rather spend that big $$$ on something else if I can! And if that didn't cure it would be pissed! Oh, and by the way, this IS a brand new driveshaft with brand new u-joints (I munched the old one on some rocks two weeks ago), and the vibes have been present ever since the lift last year. If it is just the Detroit doing its thing with its built-in "slop", I guess I can put up with it, but whatever it is it really drives me crazy!!