Slip Yoke Eliminator Kit | Jeep Cherokee XJ (84-01)/Wrangler TJ (97-06) 50-7907Product Overview Title: Slip Yoke Eliminator Kit Jeep Cherokee XJ (84 01) Wrangler TJ (97 06) Jeep model NP231 transfer cases have one glaring weak point. They use a slip yoke on the rear output shaft of the transfer case instead of having a fixed yoke and a drive shaft with slip splines. This design works fine on the street but once you have lifted your Jeep and installed bigger tires on it, the stress on the slip yoke or rear output shaft is often