Compatible With:
LJ
The factory Jeep LJ rear frame was never designed for long wheelbase, coilover suspension builds. The frame rails sit inside the body, behind the axle, and limit how far you can move the axle rearward. This creates problems with wheelbase stretch, suspension geometry, and departure angle.
Once you start trying to run larger tires and a true four link suspension, the factory frame becomes the restriction.
A back half kit solves this by completely replacing that rear section of the frame.
The Motobilt Jeep LJ back half kit removes the factory rear frame rails and replaces them with a new structure designed to allow proper wheelbase stretch and suspension layout. By cutting off the factory frame and installing this system, you can move the rear axle rearward to match your build goals while keeping the chassis structure clean and functional.
The new frame rails are repositioned from inside the body to underneath it and tied directly into the bottom of the rear floor. This change opens up the entire rear of the chassis for proper link placement and coilover packaging. Instead of working around the factory layout, you are now building the suspension around a structure designed for it.
This is what allows a Jeep LJ to run longer wheelbase setups, larger tires, and proper four link geometry without compromise.
At the same time, the bumper is relocated up just below the tailgate. This reduces rear overhang and improves departure angle, which becomes more important as the wheelbase increases and the vehicle is used on steeper obstacles.
The system is designed for real fabrication. The upper and lower frame rail sections are joined during mockup so you can position everything based on your desired wheelbase and axle location. This gives you the flexibility to build the Jeep the way you want instead of being locked into a fixed layout.
The included 50 inch stubby rear bumper is built from formed plate and features 3/4 inch thick d-ring mounts that pass through the bumper and weld on both sides for strength. The structure is designed to work as part of the chassis, not just bolt onto it.
This kit is for builders who are stretching wheelbase, running coilovers, and building a Jeep LJ that performs correctly on the trail and holds up to real use.
Want To Know More?
Find all the information you need to get the right part for your rig.
Choosing the correct rear back half kit depends on your Jeep platform and whether you are keeping factory wheelbase or converting to LJ length.
Vehicle Fitment
Jeep Wrangler LJ
Material
3/16 inch high strength steel plate
D-Ring Mount Material
3/4 inch high strength steel plate
Bumper Width
50 inch stubby rear bumper
Weight
Approximately 98 lbs
Manufactured
Made in the USA
What does a back half kit do on a Jeep LJ?
A back half kit replaces the rear portion of the factory frame so you can stretch the wheelbase and build proper suspension geometry for coilovers and link systems.
How much can I stretch the wheelbase with this kit?
Wheelbase is determined by your link length and axle placement. This system allows you to move the rear axle rearward to match your build goals.
Why not keep the factory frame?
The factory frame limits axle placement, suspension geometry, and shock clearance. A back half replaces that structure so the suspension can be built correctly.
Does this kit include a rear bumper?
Yes. The kit includes a 50 inch stubby rear bumper with integrated 3/4 inch thick d-ring mounts.
Is this a bolt-on kit?
No. This kit requires cutting, fitting, and welding by an experienced fabricator.
Motobilt offers industry leading, American-made off-road parts, focusing on quality and precision. Every product is built in-house, ensuring reliable performance for your adventures. Let us be your go-to source for industry leading, top-notch gear and support in your off-road journey.
Phone: 334-219-2333
Email: info@motobilt.com
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