JKS JSpec Lift Kit – 5,000 mile review

It’s been 5,000 miles since I installed the JKS 2″ JSpec Lift Kit on the Wrangler.  I know what you’re thinking.  “But Dean, it’s only been a month.”  True.  In the last month I drove to and from Denver and back which alone was a 3,000 round trip.

Fully loaded and towing a trailer.  Barely any rear squat.  Job well done.

From the start the plan for this Wrangler was to be a triple-purpose rig.  It needed to be reliable enough to serve as a daily driver, it needed to support my overland adventures, and it still needed to hold it’s own in technical terrain like an off road park.  As such,  I’ll be breaking this review down into four categories: Around Town, On Highway, Off Road, and Towing.  Mostly I’ll be comparing the ride quality to the old factory suspension, but I’ll also throw out some of my thoughts compared to my experiences with other similar kits.  Read on for details…


First, a step back

I’ve done other 2″ lift kits in the past and they each had their short-coming.  Also, don’t forget the mantra, “Never use spring rate to increase lift; Never use spring hight to increase payload.”

  • “Budget Boost” Spacers: Sure they provide lift, but they do little to address ride quality.  If anything, spring spacers will make a bad set of springs worse.  The increase in the vehicle’s center of gravity (COG) can mean old fatigued springs will feel even sloppier.
  • “Discount” springs: There are a lot of cheap springs on the market.  In a pinch they can provide some more clearance for larger tires, but they are usually made using the same spring rate as OEM springs.  That means if you’re a heavily modified Jeep with thinks like steel bumpers, winches, heavy oversized spare tires, and/or loaded up with a week’s worth of overland adventure gear you may be overloading the factory spring rate.
  • “Quality” springs: There are a few quality lift springs on the market.  A lot of times those companies have put the R&D time into figuring out an optimal lift height and spring rate combination that works for their target buyer.  Some kits are designed with rock crawling in mind, others highway driving.  A lot of times these quality kits also come with quality shocks that have been paired with the springs for their intended purpose.  The limitation here is that there are very few kits designed with overlanding in mind.  Kits designed for rock crawling rarely factor in the increase payload of an overland adventure rig.  Kits designed for the highway usually don’t preform well on rugged terrain.

Around Town

In daily-driver mode the JKS JSpec kit really shines.  I live in a rural area with pretty rough roads.  With the OEM suspension at 150,000 miles the Jeep would bottom out on the factory springs and the shocks were doing next to nothing.  The firmer JSpec springs not only provided the 2″ of lift I was looking for, but their dual spring rates really stepped up the ride quality.  Even with all my tools and an extra spare weighing down the back the Jeep barely flinches now when I hit a bump.  The suspension does it’s job soaking it up.  The front is also very firm and soak up the many potholes common to Pennsylvania roads.

On Highway

On the highway the JKS JSpec kit also shines.  Again, living in an area where highways aren’t much better than side roads, the spring and shock combo of this kit soak up the bumps just as well at hight speed as they do at slow speeds.  The firmer springs also help keep the Jeep feeling solid at high speeds.  In the past I’ve used cheaper lift springs which used the OEM spring rate.  The increase in COG allowed for more body-roll on things like exit ramps.  They also lead to a floating feeling that made you keenly aware you were driving a lifted vehicle.  With the JKS kit I get none of that.  It feels firm, solid, and responsive.  I feel like I’m driving a stock height Jeep despite the 2″ of springs, 1″ body lift, and larger tires.  Leads to a much more secure and confident feeling which I can’t way I always get when in a lifted Jeep.

The initial shake-down run on Ridge Road in Michaux State Forest.
The springs and shocks do just as well on a fire road as they do a highway or around town.
No complaints.

Off Road

At this time I haven’t logged too many off road miles yet, nor have I had the chance to stretch her legs on anything more technical than a forest service access road.  That said, this kit rides like a dream off road at a cruising speed of around 20-30 mph.  I’m not saying this kit is good enough to go pre-running in, I’m not crazy enough to push my luck that far, but at a respectable (and legal) speed through the local state forest the springs and shocks never missed a bump.  Even with fully inflated tires and a connected sway-bar the Jeep was able to ride solid down the gravel and dirt roads.  It bounce through washouts like they weren’t there.  I’m not saying it’s a miracle lift kit, it’s still a Jeep with solid axles, but compared to an OEM suspension or a cheaper lift kit this kit is worth the investment.

Towing

Slap a trailer behind any vehicle and it’s bound to handle differently.  The increase in load on the rear axle combined with the extra weight tugging at the back of the Jeep and handling changes.  I’ve seen a lot of Jeeps squat when hooked to a trailer.  This isn’t uncommon and that’s why a lot of 4×4’s come with a slight rake to the front.  That little bit of extra height in the back levels out under load and/or when attached to a trailer.  In the case of the JKS kit I honestly don’t feel like the trailer is back there. Granted it’s a relatively light trailer that is balanced very well.  The tongue wait is just enough to keep the trailer from getting squirrelly at highway speed.  That said, the back end stays nice and firm under load and there is no lift on the front end.  In my old Jeep, a ’97 ZJ with 2″ a discount spring/shock kit I always felt like the rear became squishy when towing.  Even a small utility trailer with 2,500 lb limit was enough to make me with I had a set of airbags in the rear to help out.  So far this JKS kit has taken everything I’ve thrown at it and not backed down.

Conclusion

Obviously these are just my subjective thoughts and feelings based on my own limited experiences with the kit so far.  I’ve spent a lot a time on the highway so far so I’m anxious to get the Jeep into some technical terrain.  Hopefully when I return from the UT/AZ/Expo/CO trip I’ll have a more details for the next 5,000 mile writeup.