6. The Extreme short-shaft kit replaces the rear output shaft of the transfer case and the tailhousing for additional driveshaft length. The kit allows for a 7-inch-longer rear driveshaft, helping to reduce rear driveshaft angles and replacing the rear slip yoke with a fixed yoke. This kit does require a new rear driveshaft to be made. When you compare it to the stock output shaft, you can see the length decrease and the shaft diameter increase we gained.