Long story I won't repeat but outlined in another post named LIFT PROBLEM. Anyway, back for help. Severe vibration after 4 inch lift of 99 wrangler 4.0 including pittman arm. Although I was told I needed a slip yoke eliminator here on the forum, 4wheelparts.com manager says don't need slip yoke eliminator to fix the problem because they've never sold a SYE for this particular lift kit. He says the driveshaft shim needs to be adjusted for the pinion angle to correct the vibration. Well, for a layman like me, I have no idea what to do. Can you help with instructions and was this correct info I received? Thanka!