Urban Trailseeker: Jeep Cherokee XJ - Rubicon Express 2" Rear Add-A-Leaf

A couple of months ago, I decided to install a 2" Spacer and Shackle Budget Boost on my Jeep. Turns out, when extended shackles are paired with the original leaf springs, it further increases the wear on the spring. This leads to even saggier leaf springs than before, quickly losing the "boost" in the rear. The best solution is to replace the leaf springs altogether with some heavy duty springs, but a much more affordable solution is to add an extra leaf to the existing pack to give it some support.

Rubicon Express 2.5" Add-A-Leaf

To match the 2" coil spaces in the front, I purchased a 2.5" add-a-leaf kit from Rubicon Express. There are two different types of add-a-leaf kits: short and long. Short leafs are stiffer and provide support closer to the bottom of the pack. Long leafs are a little softer, but provide support over a wider length of the pack, closer to the main leaf. More information about the different types of leafs can be found on this JeepForum post. The Rubicon Express leafs I purchased are long add-a-leafs.

Here is a list of parts I purchased:

Jacking up the Rear

The first part of the install is to jack up the rear end to get access to the leaf pack. Chock the front wheels and loosen up the nuts on the rear wheels, but do not remove them. Stick a jack underneath the rear differential and lift the rear until the wheels are off the ground. Stick some jack stands under a frame right in front of the leaf pack. Lower the vehicle and let it rest on the jack stands. Now, the wheels can easily be removed.

Once the rear wheels are off, disconnect the lower shock mounts. This will allow the axle to drop even further. Be careful and watch the brake lines. Dropping the axle too far will rip them right off!

Getting Rid of the Rear Sway Bar

It's a well-known mod to remove the stock rear sway bar on the XJ. It allows the Jeep to have more articulation when driving off road, with little change in how it drives on the road. Since the sway bar mounts need to be removed to get to the leaf pack, this is a good opportunity to get rid of it altogether.

The sway bar mount is attached to the leaf pack through the outer U-bolt. First, remove the bolt holding the sway bar to the mount. Then, remove both U-bolts, this will free the sway bar mount.

Also, up on the uni-body, there are rubber mounts holding the sway bar up away from the axle. These can be removed as well.

Once these are removed on both sides of the vehicle, the sway bar can be carefully maneuvered out from underneath. The upper rubber mounts can be thrown away. However, the lower mounts can be used as bar pin eliminators for the rear shock mounts. They can be bolted directly in, but this is not recommended because it rotates the upper mount for the shock (90 degrees). This puts all the pressure on the bushing when the axle moves, rather than allowing the eye to rotate. Instead, weld the mounts at the proper rotation.

Taking Apart the Leaf Pack

The leaf pack is held together by clamps on the ends and a long center pin. First, remove the old U-bolts and plate. The plate is held down by the 4 washers attached to the U-bolts. Simply undo the 4 washers and slip the U-bolts right out under the axle.

Now, remove the clamps on the ends using a tough screwdriver or small pry bar. There should be one on each end of the leaf pack. These can be a pain to get off if they are rusted onto the pack, so use some muscle and be patient.

With those removed, place C-clamps near the center of the leaf pack to hold it together while removing the upper washer on the center pin. Use a vice grip to hold the head of the center pin below, while undoing the washer up above with a wrench. Once the center pin is out, slowly undo the C-clamps, allowing the leaf pack to come apart.

Adding the Leaf

The new leaf spring will be added right below the main leaf (the one still attached to the shackle). The "large-to-small" leaf order should be preserved. In order to get the axle to drop even further, the brake line underneath the driver side should be disconnected. Using a screwdriver, keep the holes for the center pin aligned while re-assembling the pack.

Using the C-clamps, slowly compress the pack back together. The screwdriver can be used again to keep the hole for the center pin aligned. When the pack is fully compressed, re-install the center pin.

The new clamps will go on the ends of the leaf pack where the old ones used to be. The particular ones I purchased simply slip into each other and bend outwards to hold together. Make sure these are nice and tight! Nobody wants to have the leaf springs decompress while driving on (or off) the road.

The old U-bolts probably have stretched out over time, so do not reuse them. It's a good idea to purchase new, longer U-bolts anyway. These go on the same way the old ones came out. Make sure these are nice and tight. After driving around a bit, come back and tighten these again. The axle needs to be tightly attached to the leaf springs to prevent any unwanted shifting while driving.

Repeat the entire process on the other side.

Enjoy the Lift!

With the new leaf added to the pack, the rear end of my Jeep lifted up a little under 3". The rear sits a bit higher than the front. However, this will settle down to about 2.5" over time. The ride is a bit rough, since the leaf pack is stiffer, but it's a Jeep.

Good luck with your own add-a-leaf kit! Happy wrenching!

Urban Trailseeker

Jeep Cherokee XJ - Rubicon Express 2" Rear Add-A-Leaf