JeePerf Differential Drop System for Jeep WK/XK lifted 2" or more. NOT RECOMMEND WIH SPACER LIFTS.
 
Your IFS front differential is mounted to your chassis and is coupled to your front wheels by half axles that use CV joints to transfer the motion.
 
When you lift your WK, you are effectively furthering the vertical distance between your chassis and your wheels by that much height of your lift. What this does is increase both the distance AND the angle of any component connected between your chassis and your drivetrain. That includes your front wheel drive system which, in this case, is driven by your half axles.Half axles are designed by factory engineers to handle the angles imposed by a flexing front suspension WITHIN specified design range parameters. When you lift your vehicle, you put your front drive train outside its normal design range, forcing your CV joints to operate at steeper angles than what they were designed for. This causes accelerated wear on your half axles, and you end up having to replace your front axles more frequently than you want.
 
There are two solutions to solve such a problem. They both revolve around making your front axles' CVs operate WITHIN their design range.
 
The first solution is to install very high end CV joints, designed to operate at steeper angles. Those tend to be highly specialized, in short supply, expensive to purchase and are custom built which usually take a longer time than you are willing to wait. Due to their highly specialized nature, those can also be discontinued at any time due to their high cost to build and according to market demand.
 
The second solution is to drop your whole front differential down to bring your OEM front axles’ CV joints back to their normal design range of operation. This solution tends to be a simpler, more direct and more cost effective approach to solve the same problem. This solution will require no special maintenance and is an install-and-forget approach to solve the same problem. This is the approach we took and we succeeded in finding such a solution.
 
Introducing our front differential drop system. It shifts the angles of operation of your CV joints back to their NORMAL operating range, to eliminate vibration and reduce excessive OEM CV joint wear.
 
With our solution, you end up having your desired lift AND NOT HAVING TO UPGRADE OR FREQUENTLY REPLACE YOUR FRONT CV AXLES. This solution is simple to install and, once installed, it requires no special maintenance.
 
This differential drop system comes with a pair of MANDATORY narrow profile differential bushings and is highly recommended for 2" lifts and above. It will require installation of the new bushings and professional trimming and reinforcement of your front crossmember to allow the free rotation of your front propeller shaft at its new position. 
P.S. The new position of your front differential WILL accelerate the wear of your front OEM propeller shaft which will ultimately fail. At that point, we highly recommend replacing your OEM front propeller shaft by a double Cardan propeller shaft to be able to handle the steeper angle imposed by the new position of your dropped front differential.