Once a Jeep TJ or LJ moves past factory control arm suspension and into a real linked chassis, the frame side mounting points become one of the biggest fabrication challenges in the build. Getting the upper and lower link mounts in the correct location takes time, and if the frame side structure is wrong, the entire suspension layout suffers. Builders end up spending a lot of time measuring, mocking up brackets, and trying to keep everything square while still packaging the skid, drivetrain, and frame rails correctly.
The Motobilt Jeep TJ / LJ Four Link Suspension Kit is designed to remove much of that guesswork by providing a fully welded frame side assembly that houses both the upper and lower links for the front and rear suspension. The rear utilizes a 4-link design, while the front can be run as either a 3 link with a track bar or a true 4 link front depending on the steering system being used. The parts locate from the factory skid plate mounting holes, which simplifies positioning during installation while still allowing the system to be welded solidly to the frame.
This kit is built for serious fabrication work. The skid and main link mount bodies are made from 1/4-inch steel plate, while the secondary boxing plates and internal gussets are 3/16-inch steel plate. The link mounts are completely boxed for strength and designed around specific rod end and spacer dimensions that are important to proper fitment. This system was developed for builders putting together high-clearance TJ and LJ chassis with a wheelbase range of 104 to 118 inches. It is a foundation piece for linked suspension builds where strength, layout, and suspension packaging matter.
Recommended Suspension Joint Details
Lower Links
Require a heim joint with a 1 1/4-inch threaded shank
Bolt hole size is 1 inch
The 1-inch bolt hole will be reduced to a 3/4-inch bolt hole
Reduction is done using 1 inch to 3/4-inch-high misalignment spacers
Spacer width must measure 2 5/8 inches
Lower link boxes have a mounting width of 2.63 inches
Lower link mounts were designed with 1.25-inch x 1 inch rod ends with 1 inch x 3/4-inch-high misalignment spacers
Johnny Joints with the same 2.63-inch mounting width can be used, but may require weld washers to change the bolt hole size, which is 3/4 inch
If using a Johnny style joint in the lower link mounts, MB1575 weld/reducer washers will allow you to weld into the lower link mounts and convert them from a 3/4-inch hole to a 9/16-inch hole
Upper Links
Use a heim joint with a 7/8-inch threaded shank
Bolt hole size is 3/4 inch
The 3/4-inch bolt hole will be reduced to a 5/8-inch hole
Reduction is done using 3/4 inch to 5/8-inch-high misalignment spacers
Spacer width must measure 1 3/4 inches
Upper link mounts were designed for 7/8-inch x 3/4-inch rod ends with 3/4-inch x 5/8-inch-high misalignment spacers
Upper Mounts will not work with Johnny Joints
The 7/8-inch rod ends were chosen to keep the mounts tight to the front frame rails and allow room for many different engine setups
Important Information
Designed for Jeep TJ and LJ 4 link suspension conversions
Rear utilizes a 4 link design
Front can be run as a 3 link with a track bar or as a true 4 link
Designed with a wheelbase range of 104 to 118 inches
Main bodies and skid are 1/4 inch steel plate
Secondary plates and internal gusseting are 3/16 inch steel plate
Ships fully welded and ready to install
Requires welding to the frame
Does not require body removal for installation
Parts locate using the factory skid plate mounting holes
Sold as a kit
Approximate weight is 126 lbs
Suggested related part not included: Universal Transmission Crossmember Kit part number MB3077
Product Specifications
Suspension Configuration: Rear 4 link; Front 3 link with track bar or front 4 link
Material: Main bodies - 1/4-inch steel plate; Secondary plates - 3/16-inch steel plate
Wheelbase Range: 104 to 118 inches
Weight: 126 lbs approx.
Manufactured: Made in the USA
Notes
Requires removal of the factory spring hangers
Link mount sections bolt to the factory skid plate mounting locations for initial positioning
Included skid plate attaches to the system during installation
Kit requires welding to the frame and is not a bolt-in kit
Body does not need to be removed to install
If front suspension is being run as a 3 link, simply remove the upper link mount on the front side not being used
Motobilt track bar brackets can be used if running the front in a 3-link configuration
If using a traditional steering box or hydraulic assist, the front is often run as a 3 link with track bar to prevent bump steer
If using hydraulic steering, the front can be run as a true 4 link
