Well I am not new at this but it is realy pissing me off. Had the 4.5 SF lift on now for 5k and no problems. One trip to moab and all the lca bushings were sliding out, the rear was sagging and vibes. Called RE gave them the details with the spring measurements. I have a 5sp,stock rear track bar with the 1602 bracket for a cv shaft, hardtop, durango bumper/swingout with a gerry can and highlift. They sent me new bushings and 3/4" spacers. I installed it and now I cant get rid of the vibes. DS is at 18 and pinion is 17. Vibe is from 51 to 59 mph. Mind you this is the second shaft, first one would not stop vibrating at all. I had to rotate this one 3 times originaly when mounting it to get it to ballance out.(mount it, rotae 90 on the flange bolt it up, still vibe, rotate it 90 more and vibe was gone until MOAB) I know it worked good befor but I cant get it to now. I have had it at almost dead on DS at a little over 18 and pinion almost at 18 and all kind of other combos. Out of ideas please help.