Installing a long arm kit on a Jeep Cherokee XJ is one of the biggest suspension upgrades you can do. It requires some cutting and drilling, but the payoff is drastically improved ride quality, better articulation, and a suspension geometry that actually works with a lifted XJ. In this video, Spence and Gabby from Core 4x4 walk through the complete long arm kit installation on the shop XJ Cherokee as part of their ongoing XJ build series.
This is the second video in the series. The first covered full front-end teardown and disassembly. If you missed that one, some of the prep work shown here — like removing rusty factory hardware — is covered in detail there.
Fitment: Jeep Cherokee XJ 1984–2001
Before You Start: Springs and Shocks First
Spence starts a little backwards by installing the springs and shocks before the long arm kit. The reason is simple: with the entire front end disassembled from the teardown video, the axle has nothing holding it to the vehicle. Installing springs and shocks first keeps the axle from falling while you work on the control arm brackets.
The factory shock eyelets use a small 8mm bolt. Spence upgraded to a 3/8-inch bolt by grinding out the eyelet slightly for a stronger connection.
Step 1: Remove the Factory Lower Control Arm Mounts
The factory lower control arm mounting brackets on the frame need to come off. Spence recommends a sawzall with a short blade for the first cut — the blade goes inside the bracket cutting from the outside in. For the back side, switch to an angle grinder with a cut-off wheel for a cleaner result.
Watch your fuel lines. When trimming the back side of the driver-side bracket, the fuel lines run right along the frame behind the mount. Be careful not to nick them with your cutting wheel.
After the brackets are removed, hit the bare metal with spray paint to keep it from rusting. This is not a show Jeep — it just needs to be sealed.
Clearance the Pinch Seam
With the factory brackets off, there is extra clearancing needed along the frame rail. Part of the unibody pinch seam sticks out where the upper control arm passes between the exhaust and the frame. Trim this back to give the upper arm as much room as possible during articulation.
Step 2: Remove the Factory Crossmember
The factory crossmember has two bolts on the frame rail and four bolts at the transmission mount. Support the transfer case before removing the crossmember — you do not want the drivetrain hanging on the motor mounts.
If your XJ still has the factory stud in the crossmember hole, you need to remove it. Use vice grips or thread two nuts against each other and spin it out. The stud is threaded in, so turn it — do not cut it. You need the threads in the frame for the new hardware.
Step 3: Mock Up and Drill for the Frame Brackets
Hold the frame brackets up against the unibody, lining them up with the factory crossmember bolt holes. Mark where you need to drill.
- Rear hole: Drill all the way through both sides of the unibody
- Front hole: Drill through the front side only, then use the included nut tab on the inside to capture the bolt
- Drill bit size: 5/8 inch
You can leave the bracket in place and drill through the bolt holes for perfect alignment, but Spence prefers to mark the holes, remove the bracket, then drill. Drilling through the bracket scrapes the powder coat off the mounting holes, which can lead to rust.
The Core 4x4 frame brackets are slotted, which means they work with aftermarket frame stiffeners. The slots allow up to a half inch of extra width. If you have frame stiffeners, you will need to trim more of the pinch seam to get the upper mount inside, but the kit accommodates them.
Step 4: Bolt Up the Frame Brackets and Crossmember
On the rear bolt that goes all the way through the unibody, add the included large washer on the inside to spread the load. Torque sequence matters here:
- Torque the through-unibody bolts first — this seats the bracket against the frame
- Then torque the smaller bolts that pull the bracket up inside
- Install the crossmember between the two frame brackets
- Make sure your drivetrain is centered before torquing the crossmember end bolts — the slotted frame brackets allow the drivetrain to shift side to side
| Fastener | Torque Spec |
|---|---|
| Through-unibody bolts (frame brackets) | 160 ft-lbs |
| Small bolts into frame (frame brackets) | 70 ft-lbs |
| Crossmember end bolts (into frame brackets) | 130 ft-lbs |
Step 5: Set Arm Lengths and Install
Before bolting the arms in, pre-set them to approximate length. For this four-inch lift on the XJ:
- Lower control arms: 31 inches eye to eye
- Upper control arms: 32-3/4 inches (measured from inside dimension of the Johnny Joint housing)
The upper arms are trickier to measure. Make sure the joint is straight in the housing when you take the measurement, and use the inside dimension — if you flip the arm and measure from the outside, you will get a measurement about an inch longer.
These are starting lengths. Final adjustments come later when the front end is fully assembled and the Jeep is on an alignment rack.
Step 6: Check Clearances
With the arms installed, check clearances at full droop:
- Lower arms: The Core 4x4 kit has a high-clearance bend on the lower arms so they clear better at full droop. If running a higher lift or wanting extra room, you may need to trim the shock mount slightly.
- Upper arms: Check that the upper arms clear the pinch seam trimming you did earlier. The arm passes between the exhaust and the unibody, and you want to verify it has room to travel.
Step 7: Torque Everything Down
| Component | Torque Spec |
|---|---|
| Lower control arm bolts | 140 ft-lbs |
| Upper control arm bolts — frame side | 90 ft-lbs |
| Upper control arm bolts — axle side | 70 ft-lbs |
| Lower jam nuts (1-5/8") | 250 ft-lbs |
| Upper jam nuts (1-1/2") | 200 ft-lbs |
Critical: Rubber Bushing Warning
If you are still running the factory rubber bushing on your upper control arm axle housing mount, do NOT torque it in the air. Rubber bushings have a fused crush sleeve — if you torque them at full droop, the sleeve locks in that position. When the Jeep comes down to ride height, the bushing will have a preload that causes premature failure. Wait until the Jeep is on the ground at ride height to torque rubber bushings.
Everything else on the Core 4x4 kit — all the Johnny Joints — has an independent ball center, so those can be safely torqued in the air at any suspension position.
Tools Required
- Lift or jack stands
- Sawzall with short blade
- Angle grinder with cut-off wheel
- Drill with 5/8" bit
- Tape measure
- Socket set
- Torque wrench (up to 250 ft-lbs)
- Crow’s foot wrenches — 1-1/2" and 1-5/8"
- Spray paint (for sealing bare metal)
- Vice grips (for stud removal)
What Is Next in the XJ Build Series
With the long arm kit installed, the next videos in the series cover the rear suspension (removing leaf springs and installing shackles), the WJ knuckle swap for the front end, and final alignment once everything is together.
Frequently Asked Questions
Related Content
- XJ Custom Long Arm Replacement — How to Replace Arms on an Existing Kit
- 3 Methods to Rebuild or Repair Your Johnny Joints
- Why You Need Control Arms
Shop XJ Cherokee Parts
Fitment: Jeep Cherokee XJ 1984–2001. Contact: sales@core4x4.com | (385) 375-2104
