Cole
Expedition Leader
ROCKKRAWLER JK 3.5” X Factor Mid Arm Suspension System
A little background!
My JK is my 11th Jeep. I have over 20 years and over 1 million miles of Jeep ownership under my belt. I have also coached performance driving since 1992 and competed in many forms of motorsports, basically I am a hard core motor head. I only point this out to say I’m by no means an expert, but I do have a fair background to base an opinion off of.
You should also know that I have three pet peeves when it comes to Jeeps and suspension reviews. First, I hate install “write ups”. Ninety percent of the suspensions out there are going to install roughly the same way, they usually come with instructions and if you are really not sure at that point you should have a professional install it for you. Second, there is no way you can install a suspension, drive it around the block and flex it in the nearby field and call it a review. Put some real miles and time on the suspension before writing out a review. They all seem shinny, new and perfect 5 min after install. I personally want to know how well it is put together, long term impressions, what breaks, rattles, fails, etc etc. After all, if you are going to spend thousands of dollars on the suspension you should expect a little more. Lastly, I am sick of people making the excuse “It’s a Jeep, it’s not supposed to handle” or some version of it. When Jeeps were invented in the 40s they were made with the latest technology and handling. I expect the same today. If it’s not right, fix it, don’t make excuses for it.
Let’s get on with it!
Last year, yes, last year, I installed the RockKrawler 3.5” lift. That was over 20,000 miles ago. In that time I commuted to work 66 miles a day, drove from Denver to our ski areas in snow and slop every weekend, wheeled in Colorado and Utah and towed a Porsche 951 1600 miles with it. Not a complete list, but you get the idea of the type of work the Jeep and suspension had to do in that time frame.
Why RockKrawler?
Hardcore durability! That is the simplest way to put it. The components in the RockKrawler kit are as durable as you will ever get. The control arms and track bars are solid, not hollow tube. They come with a high clearance “bend’ in them that keeps them up out of the rocks. Between the angle of the lower control arms, the construction and the RockKrawler warranty you will never ever have to worry about a control arm again. You simply cannot hurt them. Each arm is equipped with a huge poly bushing at the frame end and a pivoting bushing at the axle end. This is done for the ultimate in off road flex and still has good on road ride qualities.
To me the second most compelling reason for the RockKrawler suspension is customizability. I started with their 3.5” X factor kit. This got me all the basic hard core arms, brake lines, springs, and track bar correction I wanted. Add a high quality set of shocks and you could call it done. Decide you want more in the future and you have a great system to build off of. Upgrade to their long arm kit, heavy duty steering systems, taller springs etc.
So how does it work?
On Road!!!
As I noted above I put on 20,000 miles before ever commenting on the suspension. The on road performance is the most important part of a suspension system for me. Even the most hard core wheelers drive at least some of the time on the street. At this point in the JKs lifespan I would bet that most of the JK owners use their Jeeps as daily drivers so on road performance is very important.
I was pretty disappointed in the stock JK suspension on the street. It was too soft and wiggly on rough roads and expansion joints. The Rockkrawler suspension firmed up the ride and matched with the Fox Racing Shox was much more stable at speed when the road got rough. I have a couple of spots on my daily grind that were almost scary on the stock set up. A couple of off camber 65 mph expansion joints that arise mid corner that will turn your knuckles white. Along with a stretch of back country road that would just send the JK almost sideways even at moderate (legal) speeds. These problems were almost totally eliminated with the RockKrawler suspension. Using a cheap spring spacer on stock springs and cheap shocks would have certainly left the issues or made them worse.
I had the unfortunate opportunity to test the durability and stability of the suspension out at 75 mph on I-25 North of Denver, Co. A roll of carpet about 2.5’ round fell out of a truck in front of me. I swerved left and clipped the roll with only the right wheels HARD!! The impact sent the Jeep airborne and slightly sideways. I landed the Jeep safely pointed down the road the correct direction. I noted three things I was VERY happy about. First, the ability to absorb the initial impact with little impact to the steering wheel was key in maintaining control. Second, the follow up landing was also very controllable and compliant. Lastly the shear durability of the RockKrawler components became immediately valuable. The Jeep took on zero damage to the suspension components. The only thing I was disappointed about is that no one caught it on film.
Dirt Roads!!
We took the JK over several mountain passes and rough dirt roads in stock trim and with the RockKrawler suspension. I actually tried to drive from Moab to Denver using as much dirt as possible. We spent hours and hours on dirt. I was amazed to find that my new JK drove worse on some of these roads than my 10 year old TJ. The RockKrawler suspension with the Fox Shox is hands down more stable and allowed us to travel at higher speeds with confidence. In many spots, probably too much confidence. In stock form the Jk wants to walk out on wash board roads much more than with the new set up. The springs and shocks seem almost out of sync stock.
I do notice a touch of bump steer. Not much, but it is there. Some of this could be my alignment, my wider wheels or my tires. I have looked at addressing it and have not found a solution yet. Initially I ran the stock Rubicon wheels on Spidertrax spacers and the Jeep drove awesome. The move to wider rims brought some wander that I’m sure some adjustments would cure.
On the Trail!!
This is really what this suspension is all about. It is designed to swallow up large rocks and spit them out without missing a beat. It has tons of smooth controllable flex. The control arms are nearly impossible to drag on a rock with the way they are curved . They let the tire contact the rock first almost ever single time. That being said, they are designed to take a serious beating. If you can drag them on every rock you can find with confidence of making it home!
We took the Jeep up a couple of my favorite trails here in Colorado. Trails that eat rigs…..well, at least trails rated in the 7-8 out of 10 range. After all I still only have 22,000 miles on the JK. We did wheel it hard, take the hard lines and loved every minute of it. The RockKrawler suspension really shines in the rocks. The rear control arms of the suspension are 1” longer than stock. Rockkrawler did this to make room for the tires to tuck and not have to trim any of the rocker or pinch seem off. It’s a close fit, but it works very well.
Car Crushing Lift!!!!
You know you have always wanted to do it!!!! We had to test the flex out somewhere other than a boring old RTI ramp. Go find yourself a classic Audi and drive on up……just kidding. I called the guys at 3Zero3 motorsports in Wheatridge, Co and asked if they had a “ramp” I could barrow and this is what they came up with. The JK walked right up on the old Audi without any drama at all. With the hood well over 7 feet high the suspension still was not fully flexed out. I only stopped to save the rear glass of the car.
Long term notes to date!
My only complaint to date is that the suspension needs frequent lube to keep it quiet. Our department of transportation here treats our streets with several chemicals to melt ice and snow. I always wash the underside of the Jeep when I clean it. This also tends to spray off the lube on the control arm joints and then if squeaks and you must re-lube it. Now keeping in perspective that this is a high performance off road suspension and it will need more work than a stock one to keep it functioning at its best over time.
