JT Gladiator Rear 3.0 Inch Lift Coil Springs Synergy MFG

Synergy Manufacturing SKU: FSVG_8865-30


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Synergy MFG Jeep JT Multi-Rate Rear Lift Coil Springs. Synergy MFG has designed these springs from a clean sheet for the new Gladiator platform. All springs are multi-rate and have been designed to make a great platform even better. These springs are unique to the JT and not shared with any other vehicles. Multi-rate design has a soft initial rate which prevents the spring from coming loose, even with long travel shocks. The ride rate is the average of the OEM spring rates to maintain adequate payload and towing capacity. Springs are proudly manufactured in the United States of the highest quality steel. Springs are designed to be able to set solid (fully collapse) without overstressing the material and are pre-set from the factory meaning the springs will never sag or set.


  • Increased ride quality
  • Increased wheel travel/articulation/traction
  • No spring bowing
  • Lifetime warranty/guarantee against sagging and breakage


  • Multi-Rate coil springs allow for longer spring lengths and increased travel
  • Spring rates are similar to stock to maintain payload and towing capacity
  • Coil spring block heights designed around common bump stop spacings to optimize wheel travel
  • Frequency balanced and tuned spring rates to maximize suspension performance on and off road
  • Abrasion-resistant black powder coat finish for maximum durability and corrosion resistance
  • Sold in pairs


  • Coil springs require proper bump stop spacing with Synergy 8057-10 Bump Stop Spacers.
  • Lift heights are based off fully optioned Rubicon models. Other models will see more lift.
  • Coil springs retain the stock rake of the vehicle.
  • Up to .75 inch of front coil spring spacer can be added to level the vehicle using 8017-075 front coil spring spacers.
  • Minimum bump stop spacing listed is the minimum amount of bump stop spacing required to prevent the springs from going into coil bind. Do not use less bump stop spacing.





Tables (lift heights and proper bump stop requirements)

Part #

Lift Height

Spring Rate (Initial/Ride Rate)

Collapsed Length

Extended Length

Min. Bump Stop Spacing



165/250 lb/in






165/250 lb/in






165/250 lb/in





Additional Information:

Like most other high-end long travel coil springs on the market, we take advantage of using multiple spring rates to increase the extended travel of the spring. Gone are the days where coil spring retainers are required to keep your springs from falling out on the trail. From our experience, there is a lot of misunderstanding on how multi-rate coil springs work, and why they would be preferred over linear-rate coil springs and vice-versa. In short, it depends on the application and what constraints we are working with. With the new JT platform we were able to design a dual-rate coil spring with a softer initial rate that is used at unloaded ride height.  As the vehicle is loaded the spring rate increases to minimize sag and maintain payload capacity. 

Our spring rates were kept similar to the stock Gladiator spring rates in order to maximize flex and traction off road in addition to allowing us to maintain a payload and towing capacity similar to stock. 

Due to variances between Jeeps and how they are used, we designed these springs to match the stock rake of a fully optioned Rubicon. If you want the vehicle to sit level (without the stock rake) when unloaded, our front coil springs will accommodate up to a .75 inch front coil spacer without requiring additional bump stop spacing (8017-075). This means that the ride height and rake of the Jeep can be fine-tuned in order to get the perfect ride height without compromise. 

Synergy MFG Jeep JT rear coil springs have very long free (extended) lengths. Due to this fact, we generally recommend that the end user make sure they are using the correct shocks in order to maximize available wheel travel. Our shortest springs will allow for around 12 inches of wheel travel front and rear. Taller springs will allow for more wheel travel. Generally, aftermarket shocks are spec’d short in order to prevent typical coil springs from falling out. We recommend at least one length longer shock for a given lift height (For example: use a 3.5-4 inch lift Fox shock with our 2 inch springs). Make sure the shock mounts and bump stops are setup to prevent the shock from bottoming out before the bump stops do.