Rubicon Express’ New Slip Yoke Eliminator Kit Is Designed To Eliminate Driveline Vibrations While Increasing The Strength Of Your Np231 Transfer Case. When Lifting Your 87-06 Jeep, Driveline Vibrations Are A Common Issue With The Increased Driveline Angles. By Converting To A Fixed Yoke, It Allows For The Use Of A Longer Driveshaft With Better Operating Angles To Help Eliminate Vibrations. Each Kit Includes A Replacement Output Housing, Heavy Duty Main Shaft, Rear Output Yoke And All Necessary Hardware.