LJ Wrangler 3.5in Lift Kit Rear Install -- Core 4x4 Camp Series Guide

Teardown to install -- bump stops, trackbar relocation bracket, brake lines, control arms, shocks, end links, and rear track bar on a 3.5 inch lifted LJ Wrangler.

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LJ Wrangler 3.5” Lift Kit Rear Install – Core 4x4 Camp Series Step-by-Step

Part two of the LJ build picks up right where the GenRight fender and fender liner video left off. The LJ is stripped and ready for suspension work, and this install covers the complete rear end: teardown of every factory suspension component, drilling and tapping the bump stop pads, installing the trackbar relocation bracket, running new rear brake lines, bolting in Camp Series upper and lower control arms, hanging shocks, connecting sway bar end links, and setting the rear track bar. If you are lifting a TJ or LJ Wrangler with the Core 4x4 Camp Series 3.5-inch kit, this is the rear-end walkthrough you need before moving to the front.

Fitment: Jeep Wrangler TJ 1997–2006 | Jeep Wrangler LJ Unlimited 2004–2006

About the Kit

LJ Wrangler in the Core 4x4 shop ready for the Camp Series 3.5 inch rear lift kit install

The Core 4x4 Camp Series 3.5-inch lift kit is designed as a complete bolt-on suspension package for the TJ and LJ Wrangler. It includes everything you need for both front and rear — coil springs, upper and lower control arms with Johnny Joints, bump stop extensions, shocks, sway bar end links, and adjustable track bars. This video focuses exclusively on the rear half of the kit.

The Camp Series sits between the entry-level Cruise Series and the heavy-duty Crawl Series. The arms use adjustable-length tubes with Johnny Joint rod ends and independent crush sleeves, which means you can set exact arm lengths for your tire and fender setup and torque the crush sleeves at any suspension position without preloading the joints.

Prepping the Jeep

Before pulling a single bolt, take a few minutes to prepare the LJ. Spray every suspension fastener with penetrating fluid the night before if you can. These bolts have lived under the Jeep for 20 years and they will fight you if they are dry.

Get the Jeep on a lift or safely on jack stands with the rear axle supported
Remove the rear wheels
Have a drip pan ready for brake fluid
Lay out the new kit parts so you can confirm everything is there before you start tearing things apart

Teardown of Factory Parts

Rear suspension teardown in progress on the LJ Wrangler showing factory control arms and track bar

The teardown is straightforward but requires a wide mix of socket sizes. Pull every rear suspension component in the following order:

Lower rear control arms — 13/16” socket and wrench
Upper rear control arms — 15 mm socket
Rear sway bar end links — 15 mm wrench and 18 mm socket
Brake line attachments — 13 mm socket
Rear track bar (frame side) — 15 mm wrench and 18 mm socket
Shocks (upper and lower) — 13 mm and 18 mm sockets
Rear track bar (axle side) — T55 socket
Upper bump stop cup — 15 mm socket

Pro tip: Once all the control arms, shocks, and track bar are removed, the rear axle will be completely free-floating under the Jeep. Support it with a floor jack so it does not drop and damage the brake lines or e-brake cables.

With everything pulled, you should have a bare rear axle hanging on the springs (or completely free if the springs fell out). Set all the old hardware aside — you will not need it again.

Drilling and Tapping the Factory Bump Pads

Close-up of the rear axle bump stop pad area on the LJ during the drilling and tapping process

The factory bump stop pads on the rear axle need to be drilled and tapped to accept the new bump stop extensions. This is the same process as the front — you are creating a threaded hole in the center of each axle-side bump pad so the extension puck can bolt on.

Procedure

Find the center of the bump pad by measuring two diameters at 90 degrees and marking the intersection
Punch the center mark to keep the drill bit from walking
Pilot drill with a small bit, then step up to the 7/16” bit
Tap the hole with a 1/2-13 coarse thread tap
Blow out the metal shavings and thread in the bump stop extension bolt

Important: Do this while the axle is free and drooped as far as possible. Once you start installing control arms, access to the bump pad inside the coil pocket becomes very limited.

Trackbar Relocation Bracket

On a TJ or LJ, the rear track bar runs from the passenger-side frame rail to the driver-side axle housing. When you lift the Jeep 3.5 inches, the factory track bar mounting point on the frame is now too high relative to the axle, which puts the bar at a steep angle. That angle causes the rear axle to shift off-center toward the driver side.

The trackbar relocation bracket drops the frame-side mount point down to match the new ride height. This keeps the track bar closer to level and the rear axle centered under the Jeep.

Installation Notes

The bracket bolts to the existing frame-side track bar mounting holes — no welding or drilling required
Torque the bracket hardware to spec before installing the track bar itself
The new mounting hole on the bracket will accept the adjustable track bar included in the kit

Rear Brake Lines

Rear brake line routing on the LJ Wrangler during lift kit installation

With 3.5 inches of additional lift, the factory rear brake lines may not have enough length to accommodate the increased droop travel. If your factory lines are tight at full droop, you need extended brake lines.

Rear Brake Line Tips

Disconnect the factory hard line at the junction on the axle housing — use a flare nut wrench to avoid rounding the fitting
Route the new line along the same path as the factory line, securing it with the provided brackets
Use fresh copper washers at every banjo fitting
Leave enough slack for full axle articulation in both droop and compression
Bleed the brakes after everything is connected — start at the wheel furthest from the master cylinder (passenger rear) and work toward the closest

Control Arms

The Camp Series rear control arms are adjustable-length with Johnny Joints at both ends. Set your arm lengths on the workbench before crawling under the Jeep.

Setting Lengths

Measure center-of-bolt-hole to center-of-bolt-hole. Use the same tape measure technique from the front install — hook the 1” mark on one bolt center and read the far end, then subtract one inch.

The exact rear arm lengths depend on your tire size and fender setup. Core 4x4 provides recommended lengths in the kit instructions. The key rule: left and right arms must be identical. Even a half-turn difference between sides will push the rear axle off-center.

Installation Order

Install the upper control arms first — they are harder to reach once the lowers are in place
Install the lower control arms
Use a floor jack under the axle to raise or lower it into alignment with the frame-side mounting holes

Installing the rear upper control arm on the LJ with Johnny Joint hardware visible

Torque Specs

The Camp Series arms use Johnny Joints with independent crush sleeves. The crush sleeve is separate from the joint, so you can torque the nut down without affecting the joint’s range of motion.

Component	Torque Notes
Johnny Joint ends (crush sleeve)	Torque at any position — crush sleeve is independent of the joint
Factory rubber bushings (if reusing any)	Torque at ride height only — rubber preloads at angle if tightened at droop

Critical: If you are reusing any factory rubber bushings on the axle side, those fasteners must be left snug but not fully torqued until the Jeep is at ride height with full weight on the suspension. Torquing rubber bushings at full droop locks them at that angle and creates a destructive preload.

Shocks

With all four rear control arms bolted in, install the new rear shocks. The process is the same as the front — top mount first (quarter-inch Allen key to hold the shaft, 3/4” on the nylon lock nut), then the lower mount (13 mm hardware).

The shocks prevent the axle from dropping away when you lower the Jeep off the jack stands. Once they are in, the rear suspension is structurally complete and safe to move around on.

Sway Bar End Links

Sway bar end link installation on the rear of the LJ Wrangler during lift kit build

The rear sway bar end links connect the sway bar to the axle housing. With the taller suspension, the factory end links are too short. The new end links included in the kit provide the correct length for a 3.5-inch lift.

Thread the end links onto the sway bar and axle mounts
Set the approximate length now — final adjustment happens once the Jeep is at ride height
Do not fully tighten until the final setup in the next video

Rear Track Bar

The adjustable rear track bar installs between the relocation bracket on the frame side and the axle-side mount. This is the component that keeps the rear axle centered under the Jeep left to right.

Installation

Bolt the frame end of the track bar to the relocation bracket
Use a floor jack to shift the axle until the axle-side hole lines up with the track bar
Start the bolt by hand before impacting it to avoid cross-threading
Set the track bar to an approximate length — final centering adjustment requires the Jeep on the ground at ride height

Johnny Joint Orientation

As with the front track bar, orient the Johnny Joint so the zerk fitting points forward and the snap ring faces up toward the frame. If the snap ring ever comes loose, gravity keeps the joint internals in place. Snap ring down is a safety risk — the internals can fall out and you lose the track bar.

What Comes Next

Completed rear suspension on the LJ Wrangler with Core 4x4 Camp Series lift kit installed

At this point the rear suspension is complete. The next video (part 3) moves to the front end and covers:

Front bump stop extensions
Front coil springs
Extended front brake lines
Front upper and lower control arms (with length settings for 33s and 35s)
Front shocks
JKS sway bar quick disconnects
Adjustable front track bar

Complete Teardown Tool List

Here is every socket and wrench size used during the rear teardown and install:

Component	Tool
Lower rear control arms	13/16” socket and wrench
Upper rear control arms	15 mm socket
Rear end links	15 mm wrench + 18 mm socket
Brake line attachments	13 mm socket
Rear track bar (frame side)	15 mm wrench + 18 mm socket
Shocks (upper and lower)	13 mm + 18 mm sockets
Rear track bar (axle side)	T55 socket
Upper bump stop cup	15 mm socket
Bump stop drilling	7/16” drill bit + 1/2-13 tap

Frequently Asked Questions

Start with the lower control arms, then uppers, sway bar end links, brake lines, track bar frame side, shocks, track bar axle side, and finally the upper bump stop cup. This order gives you the most access at each step. Once everything is out, the rear axle will be completely free-floating, so support it with a floor jack.

When you lift the Jeep 3.5 inches, the factory rear track bar frame-side mount is now too high relative to the axle. This puts the bar at a steep angle, which pushes the rear axle off-center toward the driver side. The relocation bracket drops the frame-side mounting point down to match the new ride height, keeping the bar closer to level and the axle centered under the body.

Yes. The Core 4x4 Camp Series arms use Johnny Joints with independent crush sleeves. The sleeve clamps independently from the joint, so you can torque them at any suspension position — full droop, ride height, or anywhere in between. However, if you are reusing any factory rubber bushings on the axle side, those must be torqued at ride height only. Torquing rubber at full droop locks the bushing at that angle and creates a preload that destroys it prematurely.

It depends on the condition and length of your factory lines. With 3.5 inches of additional droop travel, many factory rear brake lines will be too tight at full extension. If the lines are taut or pulling at the caliper when the axle is at full droop, you need extended lines. It is safer to replace them than to risk a brake line failure off-road. Use fresh copper washers at every banjo fitting and bleed the system after installation.

With the Jeep on the ground at ride height, measure from the inside of each rear fender to the center of the tire on both sides. If the measurements are equal, the axle is centered. If the axle is shifted to one side, adjust the track bar length — lengthening pushes the axle toward the passenger side, shortening pulls it toward the driver side. Do not set final track bar position until the springs have settled after a few days of driving.