Got a lifted 1987-2004 Wrangler with driveline vibrations? These Slip Yoke Eliminator Kits are the solution. The Jeep NP231 is one of the most commonly used transfer cases today. One of it's biggest flaws is that it is too long and uses a slip yoke design at the back. This creates an extremely short rear driveshaft in the 1987 to 2004 Jeep Wranglers. The short rear driveline becomes a major concern when the Jeep is lifted. The lift causes a rise in the transfer case and creates a steep angle to the drive shaft, typically resulting in driveline vibration and stress on the slip yoke. These Slip Yoke Eliminator Kits solve the problem by going with a fixed yoke, which allows you to shorten the length of the transfer case output shaft by 4-6 inches and use the distance for a longer drive shaft. Ultimately this results in a superior drive line angle without lowering the transfer case, and will help eliminate driveline vibrations and driveshaft stress. Any serious offroader with a lifted 1987-2004 Wrangler needs one of these Slip Yoke Eliminators.