For mechanically skilled Jeep owners, the photos here show highlights of a YJ job, the most involved X2 installation. (Superlift highly recommends professional installation.) YJs require axle and shock brackets that replicate the OE TJ approach. Also, the '88 YJ used here had a Ford 8.8 rearend and a Vortec V-8 swap. Installation highlights:
* Although the job could conceivably be done at home using floor jacks and jackstands, a hydraulic lift is invaluable for lifting the Jeep on and off the axles. Even with a hydraulic lift, this installation/instruction-sheet session at 4Wheel Parts took the better part of three full work days.
* Using a plasma cutter produces more precise cuts than an acetylene torch or reciprocating saw, minimizing the grinder work.
* Errant cuts into the frame should be patched by welding on plates.
* Black Diamond front axle kits for Dana 44 and Dana 60 applications use weld-on brackets.
* A transfer-punch kit helps center the numerous holes that are drilled through the frame.
* Always check inside the frame for wires and lines before drilling through from the outside.
* After drilling pilot holes, a stepped uni-bit hogs through the frame faster than using a series of single-size drill bits.
* The unibit creates tight tolerances for the frame sleeves. Losing a sleeve inside the frame can result in a time-consuming fishing expedition.
* Button-up details include leveling the front end with the coilover adjusters, re-aiming the headlights, recalibrating the speedometer, retorquing all fasteners, greasing all zerks, bleeding the brakes, routing and securing brake hoses and breather tubes, rerouting the exhaust around the link arms, obtaining a longer rear driveshaft, and an alignment job that includes setting the caster in addition to the toe.
* If retaining the OE NP231J transfer case, a slip-yoke eliminator (SYE) kit is required. A "super short" kit provides more than 2 additional driveshaft inches but requires an electrical speed-sensor setup.
Although the X2 appears to have slightly less overall rear travel than some four-coil 6-inch long-arm TJ kits, the leaves control lateral weight transfer better than coils. This allows the X2's frontend to "stick" when a rear tire comes off the ground. Our test YJ had front and rear ARB Air Lockers, so any two tires simultaneously in contact with the ground were able to claw the Jeep out of ruts that swallowed a TJ with a 6-inch long-arm kit and dual Air Lockers.
Road ride is a bit stiffer than stock, particularly with the new D-load-range Pro Comp Xtreme M/Ts running 22 psi on the street. A competent alignment job that dials in caster is crucial for eliminating wander, and the optional steering stabilizer absorbs some road shake. Also, the Torque Fork works as intended-off-the-line launch is smooth, even under enthusiastic V-8 acceleration.
The X2 appears to achieve Superlift's goals. The kit isn't cheap (no long-arm systems are), and installation is a multi-day proposition. However, the result is a Wrangler that can keep up with many trailered trail rigs, outwheel some, and handle predictably enough to be driven home on the highway.
The rear axle must be centered...
The rear axle must be centered under the vehicle. Plumb bobs and a tape measure are used here to center the kit's spring pads in line with the frame.
Once the pinion angle is determined,...
Once the pinion angle is determined, the pads can be tacked into place. Then the rear axle is removed so that the pads can be fully welded, taking care not to warp the housing.
The rear monotube shocks attach...
The rear monotube shocks attach to the factory upper mounts. With the axle almost at full droop, the kit's lower mounts can be positioned. Then they're welded to the axlehousing.
The full-width main skidpan...
The full-width main skidpan sits in approximately the same location as the stock pan but provides drivetrain protection. It installs with recessed button-head bolts to maximize ground clearance. The pan is made from 1/4-inch-thick plate, so a transmission jack helps support it during installation.
Due to the direction of engine...
Due to the direction of engine rotation, the Torque Fork installs on the passenger side to control squat upon acceleration. It controls spring wrap by attaching to the axle at a bracket that's welded to the housing. Shackles at the axle and skidpan allow slight movement before redirecting energy, as does the Torque Fork's internal swivel.
A Heim joint threads into...
A Heim joint threads into the track-bar tubing to center the frontend. Superlift brake hoses and air locker lines were routed and secured during button-up.