Join Date: Sep 1999
Location: Hot Springs, AR
Thanked 5 Times in 5 Posts
Re: Price for RE 4.5\" extreme duty lift kit?
It is my opinion that a SOA will have less need for a track bar than a SUA spring lift. With SOA, the springs are flat from front mount to rear mount. The force applied at the bottom of the spring creates very little rotation of the spring and thus very little side to side movement of the middle of the spring.
If you draw a free body diagram of a 4" SUA spring, the force of the axle on top of the spring is still a few inches below the line between the front and rear mounts. This means the bushings and spring have a lot of twisting to resist to keep the middle of the spring from moving side to side.
In my opinion for tight steering on road, a track bar should be used with a highly arched SUA suspension, especially on the CJ's where the front springs are only 2" wide. That's a lot of torsion for the little springs and bushings to resist.