When I did my measly 2" lift, I had drive line vibes immediately, until I put in the t-case drop as a temp fix. I just made one out of rectangular steel bars, but anything would probably work. As soon as the drop went in, the vibes went down quite a bit. But they didn't truly clear up until I bit the bullet and converted to SYE w/ CV drive shaft. There is still a 1-2 degree variance from pinion to drive shaft, but no vibes, so I haven't installed the angle shims under the springs yet.
Some of the lift kit vendor sites will say "you probably won't even need a transfer case drop or notice any vibes with this lift kit." I guess it varies as to who gets them and who don't? I dunno.
[COLOR="PaleGreen"]Forest Service Green [/COLOR]1998 Jeep XJ
ya driveline vibes are so hard to pin point, there are so many things to look at and that pretty much what I'm looking at. I did u-joints tried the t-case drop, so a bigger t-case drop. it's weird because I had the vibes when I first got the Jeep with the sagged out almosted inverted springs in the back and had the vibes. now with the heavy duty springs which I think came on the UpCountry package (got em from Crown Auto) i still have vibes. but noticed the DS has a small dent in it at the very back on the pinion end. So i'm going to see if it's balanced, otherwise it'll be time for a AA SYE and possibly a new (newer) DS. I don't want to spend the money on like a Tom Woods DS. I personally don't think the price is right, some if not most will disagree with me.
Gotta bring back this thread with a new symptom. Shortly after installing the lift and doing the t-case drop about 1 1/2 inches. The vibes started to go away. Now they have worked their way back. I got a buddy we went shooting the other night one friend sat in passenger seat and he sat in the back. He weighs about 300 lbs, and doing just over 30 (i sometimes get vibes right here, not before or after 31ish) The vibes were loud! And i mean loud to the point were I almost pulled over. Now if I'm thinking of this right, him sitting there would cause the rear to squat causing the driveshaft to move in towards the t-case???? what the heck does that have to do with this tho?? I'm going to try and get the DS balanced. Way too cold to take the DS off up here in Maine. -10 every night for the past 2 wks. Please anyone know why this is happening now??