Coil over ride height adjustment is a fairly easy endeavor. You’ll need a special spanner wrench, which is usually included in the coil over kit. Depending on the design/style/manufacturer, you may need additional tools.
- To get started, with the truck on the ground, measure from the center of the wheel hub to the bottom of the fender opening. This will be your ride height pre-adjustment.
- Then lift the truck off the ground and allow the suspension to hang out fully. Repeat the measurement from hub center to fender bottom. This will be your droop measurement. Keep both these measurements for later.
- Next, use the spanner wrench to loosen the upper jamb nut. Mark the current position of the upper spring seat on the shock body.
- Measure from the top of the upper spring seat to the top of the threads on the shock body. Save for later.
- Turn the upper spring seat clockwise to compress the spring further, increasing preload and raising lift height. For approximately every 4 turns, ride height is increased by ½ an inch. From its lowest setting to its highest setting, the total amount of adjustment is somewhere between 2 to 3 inches.
- Measure again from the top of the upper spring seat to the top of the threads. Compare with specifications to be sure maximum preload isn’t exceeded.
- Once your adjustment is complete, retighten the jamb nut down against the upper spring seat. Return the truck to the ground, and move it around a bit to allow the suspension to settle.
- Once again, measure from the hub center to the fender bottom. This is your new ride height.
When you are finished, compare your droop measurement to your new ride height measurement. The difference is the amount of down travel available from ride height. For best handling and response, this measurement should be no less than 2 inches.
To adjust rebound and damping, locate the adjuster knob at the top of the coil over assembly. One way will be softer, and the other harder. Turn the knob in the appropriate direction for the change you wish to make.
Dialing it in just right make take a few attempts. You would generally want a stiffer suspension for on-road handling and comfort. For off-road applications, a softer adjustment will allow for more travel and increased comfort over rocks and obstacles.
The valving of the shock portion of the coil over is also adjustable internally. This requires disassembly of the shock absorber. Once the shock is apart, you can change the valves inside in order to tailor the damping and rebound to your specific needs. This is a more specialized procedure, so first-timers should defer to a professional.
You may also further customize your suspension to your specific vehicle by adjusting the spring rates of the coil springs. The amount of weight each coil spring will support can be nearly perfectly matched to the weight of your vehicle. This results in a much more controlled, predictable suspension response.