Four link Jeep suspensions offer a variety of benefits compared to other suspension types with regards to off-road and rock crawling performance and capabilities. Four link suspensions are set up in such a way as to have two suspension points on the edges of the body/chassis coming to a single point in the center of the rear axle. Two more suspension arms are then extended from the ends of the axle tubes to the frame, thus providing four linkages on which your truck can ride. A favorite of desert off roaders for its stability and ability to take extreme side pressure, four link suspensions can be built by anyone who has a bit of mechanical knowledge. This article will take you through the steps of building your own four link suspension for your Jeep, although the final product will something of your very own design.
Begin by designing your suspension system. Park your vehicle on level ground and measure its wheelbase and the tire size you will be running on it. Plot a point from the lower part of your axle to a midpoint on your frame somewhere. You want this linkage to have a 5 to 10 degree angle. Weld the linkage mount on the axle point and at the point where your linkage will meet the frame rail. Repeat this process for the opposite side.
Measure 8 to 11 inches from the inside of both of the lower linkage mounts on the axle and mark a point to weld a riser mount. The riser mount will lift the upper linkage mounts away from the axle, giving you more travel and better suspension control. Weld the riser on the axle and drill two holes in the top of the riser in which to install the suspension linkage. Measure along the framerail away from the suspension riser to a point half as long as the lower linkage arm will be. Weld another linkage connector on the framerail at this point. Repeat for the opposite side.
Attach the lower linkage arms with your vehicle still sprung on the leaf springs. Attach the struts to the two linkage connectors on the axle and then bolt them onto the frame rail. Disconnect the bolts holding your leaf springs on and use a jack to jack up the frame and remove the leaf spring apparatuses. Slide your upper linkage arms into place now and bolt them to the riser. Bolt the other ends to the linkage mounts on the framerail and then attach the struts to the linkage arms with the provided bolts. Let the vehicle back down off of the jacks and observe how the vehicle sits. You may need to adjust the front end suspension to match the rear at this point. You can take the vehicle a test drive and see how it handles to get a better idea of how best to tune your new four point suspension with your existing front suspension.
