Beginner's Guide To Building an '07 to '10 Jeep Wrangler JK - Wiener To WinnerPosted in How To on March 1, 2010 0) (
When you're a new Jeep owner, there's a bit of excitement about finally getting one of these cool vehicles, especially if you netted a Rubicon. You're doing the Jeep wave with other Wrangler owners, crawling over curbs in the parking lot with ease, and fearing no snow storm. But sooner or later it happens: You realize that you're just like everyone else with a stock Jeep, the high school girls, the librarians, and the Melrose cruisers.
So you break out the Jeep catalogs like a 5-year-old flipping though the toy circulars before Christmas. While that's fun and a good way to get ideas, you could end up with a Jeep that looks like it was driven through the tacky isle of your local auto-parts store. Our philosophy is to make functional mods that make a Wrangler look and perform like a real Jeep. So here are the first five modifications we'd make to a stocker to make it look a little different and perform a little better. We started with an '08 Jeep Wrangler Rubicon Unlimited. Everything we show in this article is specific to JKs, but the same philosophy can be applied to nearly any Jeep.
As an added bonus for you (and untold frustration for editor Cappa), this article took four months to put together. During that time, we accumulated more than 8,000 miles on this Wrangler, which included a few off-road trips. That means that we can share with you the drawbacks and nuances, as well as the positive comments on the parts we added. This should help you make the best choices for your Jeep and enjoy your first mods even more.
Modification 1: Suspension Lift
To fit the larger wheels and tires you're drooling over, you need to raise the vehicle. This is likely the first modification you'll want to make, and it will dictate the specifics of several of the next changes. Choosing the right suspension lift can be daunting, especially for the '07-'10 Wrangler. We counted more than 50 kits in one catalog alone!
A suspension lift and taller tires give your Jeep more ground clearance and improved approach and departure angles for much better off-road performance. The combination of these parts also makes a Jeep look the way it should.
We decided on an Nth Degree suspension system by AEV. This kit includes progressive-rate springs and Bilstein shocks that are tuned specifically for very stable on-road handling with extremely good off-road suspension travel. We also liked how this kit retains many of the factory pieces and uses OEM-quality components. Two of the engineers at AEV worked at Jeep, bringing a level of engineering expertise that shows in the design of the components.
There are two versions of the Nth Degree 3 1/2-inch kit. The standard kit comes with springs, Bilstein shocks, bumpstop spacers, brake line brackets, rear track bar and bracket, swaybar links, and cam bolts for the front lower control arms. The premium system adds a high-steer kit, front track bar and damper bracket, ProCal programmer to recalibrate the speedometer and accurately center the steering to avoid false ESP activation, a steering damper, and a jack extension base so your factory jack can raise the taller vehicle. What the kit doesn't include is longer or adjustable control arms. The company feels that factory JK arms are long enough to provide very good suspension travel. It uses cam bolts to adjust the front axle caster.
Modification 2:Larger Tires
Larger mud-terrain tires are the cornerstone of a functional off-road Jeep. Taller tires mean more ground clearance, wider tires mean more contact patch, and an aggressive mud terrain tread pattern means increased performance off-road.
The proportions of the '07-'10 Jeep Wrangler grew so much compared to TJs that 33s look stock, and anything smaller just doesn't look right at all. Going with 35s at least looks like you are a contender off-road. You can even fit 37s pretty easily. What we wanted in an off-road tire was a combination of aggressive off-road tread, very good on-road manners, and sidewall protection so we don't kill a tire the first time we go off-road. This combination isn't easy to come by, as each of those elements is at odds with the other. Aggressive off-road tread is usually noisy, and it often doesn't have good rain or ice traction on pavement. A strong sidewall often means a stiff sidewall, which doesn't offer good flex on the rocks and gives you a rough ride on the highway.
We decided to go with Mickey Thompson Baja MTZ radials, which promised to deliver on all of these fronts. Starting with tread, the unique mud terrain tread block of the Baja MTZ gives you big lugs for grabbing rocks, and big voids for slinging mud and sand. Mickey Thompson tires are also known for their shoulder lugs called Sidebiters (continuing the tread pattern onto the sidewall), which give additional traction and sidewall protection.
They provide similar on-road traction to the smaller stock BFGs we took off. The tread blocks have siping to help with wet-pavement traction. We rotated the tires at 6,000 miles and noticed an increase in road noise for the next 1,000 miles or so. This is typical of any mud terrain that gets worn in one direction and is then rotated. The overall road noise is okay - louder than the original tires, but not obnoxious. The wear is also pretty good. Mickey Thompson claims the radial tires will provide long life.
Modification 3:The Right Wheels
Wheels make the Jeep. There are hundreds of styles, so you can match your personality or create a look that you want. But cheaping out here can be costly for the overall look. The best place to start, though, is with what fits. There are a number of companies making wheels specifically for JKs. These fit the vehicle the best because the offset (and backspacing) is optimized for this application, keeping the tires from sticking out too far and from hitting everything under the front fenders.
We were more indecisive than a woman in a shoe store when it came to picking the wheels for this article, and we spent a solid month weighing all of the options. We wanted a bright wheel to balance the look of our relatively dark Jeep, but we didn't want polished aluminum or chrome which would require maintenance to keep clean. We're lazy, and this Jeep lives in Michigan where winter-weather and mud do nasty things to wheels. We eventually decided on the AEV Pintler wheels which come in either argent or the lighter silver color. Both finishes are painted with clear coat. More important than the finish, however, is that these 17x8.5 inch wheels come with a 4.7-inch backspacing, which is pretty much optimum for 35x12.50 tires on a JK. The wheels accept the factory lug nuts and tire-pressure monitoring sensors, so you don't have to buy anything extra. One thing that's a pain is that you have use a thin-wall 19-millimeter socket (included) on the lug nuts because they are recessed into the design. There's a place to store the socket in the backside of the polyurethane jack extender included with the premium Nth Degree lift kit. The valve stem is also recessed, which protects it against trail damage.
Modification 4: Protection and Good Looks
When Chrysler launched the '07 Wrangler, the joke within the Jeep team, as well as the industry, was that the new model would bolster aftermarket bumper sales for decades to come. The huge, blocky plastic bumpers are hideous. And scrape them with anything stouter than a tumbleweed and you'll have a souvenir gouge in the plastic.
Just like lift kits, there are multiple pages of flavors to choose from. Unlike past Jeeps, the factory bumpers on JKs flow around the front and rear for a blended look with the fender flares and body. If you just toss on some tube of flat steel, it's not going to look good.
Beyond appearance concerns, we wanted to make sure that we retained our receiver-style tow hitch at the rear and that we gained a winch-mounting platform in the front. We also wanted to make sure we had tow hooks or clevis-attachment points on the front. We kinda wanted to keep the factory fog lights, and we wanted a stout, rattle-free tire carrier for the rear. Oh yes, and the bumpers absolutely had to be able to sustain smacks on the rocks without being bent out of shape.
Frankly, that's a lot to ask for, but we found a few that fit the list of needs. We went with a set of Hanson bumpers with an optional spare tire carrier and front skidplate. These bumpers also improve approach and departure angles, and the use of the spare tire carrier made us ditch the third brake light, which we were happy to do. These are all stout pieces that will hold up to trail abuse and look good while doing it.
Hanson offers JK front bumpers with various widths. They're made from 3/16-inch, cold-rolled steel, accept the factory fog lights, have two clevis mounts, and feature an angled approach. We used the skinniest front bumper-the JK Stubby-which is only as wide as the grille. The winch deck is dropped two inches to retain as much airflow through the radiator as possible when we add a winch later.
For the rear, Hanson offers one style of rear bumper. It's made from the same 3/16-inch steel as the front and has a built-in 2-inch receiver for towing or to accept a clevis mount. The receiver is moved up and the bumper face is angled to maximize the departure angle. The only nit-pick we have with the rear bumper is that there isn't a mount for the factory towing wiring harness, so you'll have to zip tie it out of the way.
Modification 5: The Doors to Freedom
For our fifth mod in this article, we were torn between a set of good off-road lights, a winch, or a set of half doors. The winch was beyond our budget, and we don't do all that much night wheeling, so we steered into some HighRock 4x4 Element doors by Bestop.
We were originally drawn to the Element doors because they are available with a sheetmetal enclosure, giving you the ability to have hard half doors at about half the cost of assembling a set using Mopar parts. The enclosures come painted satin black, but you can paint them to match the body.
The tube doors create an open-air feeling with great visibility. They also provide more sense of security for the kids belted in the backseat than no doors at all. The ability to completely close out the elements with the optional enclosure kit and upper half doors is pretty handy when the weather is ever-changing. Either way, the flexibility of the whole system is hard to beat. It takes longer to remove the factory doors than it does to install the HighRock 4x4 Element doors. One challenge we ran into is adjusting the latch just right to avoid rattles. If you play with it long enough, you can eliminate the rattle, but we may end up adding a rubber bumper to make it more fool-proof. We highly recommend buying an extra set of mirrors from Bestop so you don't have to keep switching them every time you want to change doors.
What We'd Do Next
While this article gives you the five first mods that we'd make to a JK, it's also just the beginning. We have a few things we would do to make these first five modifications just a tad better. We also made some of our choices based on what we will do next to the Jeep.
The photos and captions cover what we would do to further improve upon the modifications we've already made. Beyond these steps, the next part we would add would be a winch, followed by a pair of high-quality off-road lights.
The winch is a great piece of security. Beyond being your saving grace when you're hopelessly stuck, you can use it to pull yourself out of a situation that might otherwise cause body damage to drive out of. The headlights on a JK are marginal for on-road and nearly worthless off-road. The fog lights help a bit for illuminating the immediate area, but do nothing for the mid- and long-distance areas. A set of good lights mounted on the front bumper should fill the void in nighttime vision.
Our Jeep is a Rubicon, so it has 4.10 gears and a 4:1 low-range. If it was not a Rubicon, we would have put new axle gears on the shopping list. And we'd probably go for 4.88 or 5.13 gears with a 2.72:1 low-range ratio.