I have been using the RE 4.5" Extreme Duty Lift in my 04 Rubicon for nine years. I have a third set of springs in the back. These suction cups sag about 1.5 inches or more every 25,000 miles. To make matters worse, they sag unevenly, causing your Jeep to roll. While the RE-Lift kit worked exemplary, I was disappointed with their springs.