There is some important things you should know when configuring shocks for your lifted Jeep TJ or LJ.

  • Shock Length
  • Mount Points
  • Brand and Style

Shock Length
You will need to determine the best length of shock for your setup. The most important length is to get the needed collapsed length. The extended length is essentially irrelevant for shock sizing since the collapsed length is the limiting factor. To do this you will need to get some measurements:

  • Measure the distance between the shock mount points at ride height on a flat surface. Front - center of axle mount bolt to where the stud meets the shock body, Rear - center of axle mount bolt to center of bar pin on top mount.
  • Measure the distance from the metal bump stop mount(not the rubber bump stop) to the surface of the axle.
  • Subtract the shock measurement from the bumpstop measurement and this gives you the collapsed measurement.
  • Once you have the collapsed value you will want to find the longest shock that will accommodate that value.

Rear Mount Points
There are a few options for your mounting points. The stock mounts are fine for shocks up to about 2.5 inch lift or so (Although many will opt to use bar pin eliminators (BPE) for the upper mount no matter what size lift they have). Once you go larger than 2.5 inches I would suggest adjusting your set up. When you lift the rear the pinion angle of the axle must change to account for the angle of the driveshaft. When this is adjusted correctly the issue is that the body of the shock will get too close to the coil spring mount on the rear axle. If the opposite wheel drops too much it will likely contact the shock body and damage it. A simple practice here is to simply flip the shock upside down attaching the shock body to the upper shock mount. This eliminates the close proximity of the shock to the coil spring mount. Before doing this you will need to make sure the shock is allowed to have this upside down install. Most can be installed this way.

There are other options as well. You can purchase a shock relocation bracket for that rear shock. This will solve the issue of the unwanted contact but many have expressed concerns that the new location is less ideal of an angle for the shock and adds unwanted leverage. The other option is to remove the current bracket and either re-weld it elsewhere or weld on an after market one. This would be the most ideal solution but it is also the most costly.

Brand and Style
This is highly subjective but from my own research there seems to be some agreement based on how you use your TJ. If it is a daily driver it is suggested not to use a monotube shock. Twin tube shocks tend to be a better ride on the road.