In The News Trip Reports Features Land Use Doh! Photo Album Videos Cover Shots
Project Vehicles Product Reviews Vehicle Reviews Quick Looks Wrenching Featured Vehicles YJ FAQ Calculators
4x4 Suppliers For Sale Ads Wanted Ads
Coming Events Message Board

2007 Jeep Wrangler JK

When the Jeep Cherokee (XJ) was discontinued at the end of 2001, there were grumblings from Jeep enthusiasts who felt that the Liberty with its independent front suspension was an unworthy successor. Had they known that the four-door Wrangler (JK) was just over the horizon, they wouldn't have been so upset. Jeep has done an amazing thing with their JK series of Wranglers which debuted in 2007. They've rolled the best parts of the TJ and the XJ platforms into a single product line while retaining the unique look, utility and ruggedness that was established back in the 1950's with the Willys Universal Jeep.

If you're a fan of Jeeps, you'll probably get a strange sense of deja vu looking at the four-door JK. That's because back in '97 Jeep teased us with a 4-door, full-frame, solid axle, coil-sprung concept vehicle called the Dakar. It was a vehicle that excited many four-wheelers, and ten years later with some nifty features added, you can pick one up from your local Jeep dealer.


When compared to one of the classic SUVs, it becomes obvious that the 4-door JK is firmly planted in the SUV end of the pool. In fact, it has MORE interior room than many SUVs in its class, such as the H3 and FJ Cruiser.
The JK that Daimler-Chrysler loaned us was a 4-door model and clearly, the first thing you notice about it is its length. Considering its lineage, this is a surprisingly long Jeep. It's even longer than its closest predecessor, the TJ Unlimited. For off-road applications, the added length has the drawback of reducing the break-over angle. That is, the odds of getting the undercarriage hung up on an obstacle are higher than with a 2-door model. You also lose some turning radius. But the positives outweigh the negatives. First off, you can comfortably fit five adults in this Jeep, thanks to the added length and also the added width (about six inches wider than the TJ). The ride is also much less choppy, thanks to the long spacing between front and rear axles. The JK drove much more like a firmly sprung Grand Cherokee than, say, a short wheelbase TJ. Off-road, steep climbs and descents should also be safer and easier, thanks to the long wheelbase. Need to carry a lot of gear? No problem. Even with five adults, you've got a lot of cargo space in the back. Having four passenger doors makes it easy to get in and out or access your gear, too. And the rear seats fold flat into the floor to provide a huge amount of capacity when you need it.

Speaking of which, I need to talk about those rear seats for a moment. They have two features that need to be emulated by all SUV makers. First, the seats can be folded flat in one smooth motion by releasing a single latch. As the seat back folds forward, the seat bottom flips out of the way and even the head rests fold back. It's a fast and incredibly simple process. Second, when in their upright positions, the space under the seats is available for storage. Passengers can easily stow their bags or jackets under the seat in this conveniently accessible location.


The rear bench seats have useful, accessible storage space underneath...

and they flip and fold forward with a single, smooth motion. Very slick.

With the rear seats folded, the JK has an enormous amount of room for hauling gear.

But even with the rear seats upright, there's quite a lot of cargo room in the back.

There's also storage under the floor.

This is a very kid-friendly 4x4. Lots of room and easy to get them in and out.

The rest of the interior was laid out in a very functional manner. It didn't have the plush look that you'd expect in more street-oriented SUVs. There was greater use of plastic than fabrics, but this made sense considering the off-road nature of the vehicle and the fact that it is a convertible. Off-road + no top = a very dirty interior. Plastic is much easier to wipe down than fabric. Fortunately, this didn't translate into a tinny-sounding experience. Daimler-Chrysler has done a good job with the noise quality engineering on the JK's body. The doors close with re-assuring "thunks" and wind noise is very muted when on the highway. It reminded me a lot of my XJ Cherokee, and was not what you'd expect from a vehicle with a removable top and doors.

Our test vehicle was equipped with the optional Freedom Top roof and even though it was January, we still felt compelled to remove the roof panels to see how the process worked. Without reading any instructions, we had one of the roof panels off in less than two minutes. The other one came off even faster because it utilized some of the same latches as the first. It's a very neat and simple design. Installation took a bit longer mainly because of the necessity to thread two bolts into the roof panels. I'd say it took about the same amount of time as attaching a bikini top on my YJ. With both panels off, the opening was significantly larger than your typical sunroof, providing a great open-air feeling. Well, maybe not so great in January, but you get the idea.


Removing the roof panels was very easy. We just had to flip a few latches and then unscrew two plastic knobs...

then remove the passenger side panel...

and then the driver side panel.

Ta-da!

Our JK was equipped with a CD deck capable of playing MP3's and featured an external input jack which is a great feature considering all the personal devices that are now capable of playing music (cell phones, PDAs, MP3 players, GPS units). I found the feature set and layout to be very good and the Jeep was quiet enough to really enjoy the sound quality. In addition to speakers in the dash and tweeter pods mounted near the bottom corners of the windshield, there was also a speaker box mounted atop the roll bar above the rear seat. Even with the top off, I'd expect that you could hear the music pretty well despite the wind noise.

All in all, the interior of the JK is very refined, more so than any of its predecessors. In fact, the JK is the first Wrangler series to feature power door locks and windows! And yes, the windshield still folds and yes, the doors are still removable. As I said, it's an amazing blend between your modern SUV and the classic open-top Jeep. The doors automatically lock when you drive past a certain speed, and the airbags automatically de-activate if the seats are moved too far forward. These are safety features you just don't expect in a vehicle with a folding windshield. Speaking of which, the JK is also the first convertible Jeep to use a curved windshield (better aerodynamics) and it is for that reason that it has to use a single center hinge for the folding windshield.


Like the TJ, the JK has a very modern and conventional looking instrument panel. Notice the tweeter speaker near the windshield pillar.

Here you can see the CD/MP3/tuner. Above the HVAC controls and between the two circular vents are the power window controls; something I'm still not used to seeing in a Wrangler. And check out the 6-spd shift pattern on the stick!

Despite its modern features, the JK is still big on Jeep traditions. The doors still use heavy straps to limit their opening, but now they also contain the wiring harness for the power door locks and windows. And yes, the doors are still removable!

Despite having a curved windshield frame, Jeep engineers still gave it the ability to fold flat by using a single, large, center-mounted hinge.


Because the JK has an electric fan without a shroud, there is plenty of room for working on the front of the motor.
So how does it drive? That was the question foremost in my mind when I first heard that the JK would not be powered by the venerable I6 4.0L Power Tech motor. Renowned for its torque and reliability, the 4.0L is beloved by legions of Jeep owners. In contrast, the JK is powered by the V6 3.8L. This is the 3.8L variant, known as EGH, of the Chrysler 3.3L V6, a motor which been powering Chrysler vehicles for over 15 years. Its long history means that it has had its bugs worked out and is now quite reliable, much as how the YJs and XJs were much improved at the end of their production runs. In its current evolution, the 3.8L uses a variable length intake manifold to produce 215hp at 5000rpm, and 240lb-ft at 4000rpm. Driving in the city, the 3.8L didn't feel as torquey as the 4.0L, particularly when accelerating from a stop, but it wasn't bad, either. And on the highway, it was actually quite nice. It had a good mid-range torque and didn't run out of steam in the higher rpms like my 4.0L used to. The 3.8L is also more fuel efficient than the 4.0L. With it, the JK is rated at 14.9L/100 Km in the city, and 11.6L/100 Km on the highway (see the sidebar for miles per gallon values).

Off-road, the 3.8L was great. As equipped, our JK wasn't lacking for low gearing. The six-speed NSG370 transmission's first gear ratio of 4.46:1, combined with the 2.72 ratio of the NV241 transfer case and 4.10 gears in the axles (towing package) produced a 50:1 crawl ratio which is very respectable for off-road use. The 4.0L's lower rpm torque was helpful for overcoming the relatively poor gearing of earlier Jeeps but in the JK, it wasn't missed.

So, all-in-all, we thought the 3.8L V6 was a good match for the JK. Sure, more torque would have been nice but realistically, it wasn't needed. By the way, it's nice to see that the NSG370 is using a lower first gear and also has a lower ratio over-drive (0.84:1) than previous Jeep transmissions. The reason for wanting a lower first gear is obvious, but why a lower ratio over-drive? Because we four-wheelers typically install taller tires that tend to wipe out the usefulness of the over-drive gear. Having a slightly lower geared over-drive means that it can be used with taller tires without bogging down the engine as easily.

The six speeds will also come in handy when people start building their JKs taller and heavier. The engine will have to work harder and being able to keep the engine running in its sweet spot will help keep fuel economy reduction to a minimum. I found the NSG370 to be about average as far as shift feel goes. I still prefer the shift quality of my past Toyotas to those of my Jeeps', but that's a minor point. Also, sixth was a little bit tricky to find. Many times I grabbed fourth when I wanted sixth but by the end of the week, my aim was improving.

From the outside, there's no mistaking this JK for anything other than a Jeep. The JK's extra width is clearly evident from the back, and it is partly emphasized by the squared off corners of its hard-top. From the front, it's got the trademark (literally) 7-slot grill, round headlights, and the open front fenders that immediately identify it as a Jeep. And what fenders, indeed! Big, bold, black plastic fenders have replaced the traditional steel fenders. I think this was a brilliant choice. They're more resilient to small dents, much easier to replace if damaged and you never have to worry about painting them to match the body colour.


The JK's Jeep lineage is instantly identifiable, thanks to its classic 7-slot grill and open fender look.
The JK rides on a coil-sprung multi-link suspension system like the one that first debuted on the TJ Wranglers. For the most part, the design is pretty much the same, although it is different enough that TJ suspension kits will not work with JK Wranglers. Normally, this would be a problem, but Daimler-Chrysler worked with the aftermarket to ensure that lift kits and other accessories were ready when the JK hit the dealers' showrooms. The most significant suspension change is, in my opinion, the optional Active Sway Bar System. This feature allows the driver to remotely connect or disconnect the front anti-sway bar. You get the safe handling benefits of the anti-sway bar on the pavement, and the suspension articulation benefits of no anti-sway bar when on the trail, simply by flipping a switch from inside the vehicle. This is an option on the X and Sahara trim packages, and standard equipment on the Rubicon package. This is one feature I'd love to retro-fit into my YJ. By the way, the Saharas and Rubicons can fit up to 32" tires. Moving up to 35" should require an inexpensive 2" lift. That's impressive when you come from the days of owning a YJ that needed a 2" lift just to fit 31" tires!

Our X package also came with a Dana 44 rear axle loaded with a Trac-Loc limited slip and 4.10 gears. On our test drive, it worked quite well in the snow. It took a lot time before we finally got stuck, and that was only because the Jeep finally got high centered in the deep, hard-crust snow. But for best performance, you can get the optional (standard in the Rubicon) Rock-Trak, electrically activated locking differential. Speaking of electrically activated stuff, our JK also came equipped with the Electronic Stability Program (ESP) that modulates engine output and brakes if it detects the vehicle going into an unstable situation. I left it on (although it shuts off automatically when you shift into low-range) and didn't notice it at all. In fact, I didn't even notice when I purposely fishtailed the Jeep around one particularly icy corner, nor did I notice any unusual behaviour when driving it off-road. It didn't get in my way, and that's how I like safety systems to be.

TECHNICAL SPECIFICATIONS

Model:Jeep Wrangler Unlimited 4-door
Colour: Rescue Green Metallic Clear Coat
Base Suggested Retail Price:CAD$24,495
Price as Tested:CAD$29,750
Transport Canada Fuel Consumption Ratings
City / Highway / Combined:14.9 / 11.6 / 13.4 L/100 Km
18.96 / 24.35 / 21.08 mpg (Imperial gallon)
15.79 / 20.28 / 17.55 mpg (US gallon)

Technical Specifications

Engine Type: 3.8L V6 SMPI Engine
Peak Horsepower: 202hp @ 5000rpm
Peak Torque: 240lb-ft @ 4000rpm
Fuel Required: 87 Octane
Transmission: 6-speed manual (NSG 370)
Limited-slip Differential: Yes (Trac-Loc)
Traction Control: All-speed traction control
Suspension: Front and rear live axle, five-link (four trailing arms, track bar), coil springs, stabilizer bar
Steering: Power recirculating ball with damper
Anti-lock (ABS): 4-wheel disc brakes with advanced ABS
Tires: P245/75R16 Goodyear Wrangler SRA

Dimensions and Weight

Wheelbase: 2946 mm / 116 in
Length: 4404 mm / 173.4 in
Curb Weight: 1848 kg / 4074 lb
Interior Volume: 4240 L / 150 cu-ft
Trunk/Cargo Capacity: 2460 L / 86.87 cu-ft
Fuel Capacity: 79.5 L / 21 us-gal / 17.5 imp-gal
Towing Capacity: 1588 kg / 3500 lb

STANDARD EQUIPMENT - KEY FEATURES

4-wheel disc brakes with ABS, ESP, ERM, 16-inch wheels, MP3 stereo, Sentry Key theft deterrent system

OPTIONAL EQUIPMENT INCLUDED AS TESTED

Trailer Tow Group including 4.10 Axle Ratio (CAD$350); Convenience Group including remote keyless entry, power locks, power windows with front one-touch down and security alarm (CAD$925); Trac-Loc differential (CAD$405); tubular side steps (CAD$95); Jeep Freedom Top (CAD$1,080)
So how did it perform off-road? Very well. Although I normally air down as soon as I get off the pavement, for our test drive, I left it at highway pressure to see how the suspension dealt with pot-holed and badly wash-boarded gravel roads. The suspension did an admirable job of soaking up the bumps and I didn't experience any floating around the corners that is typical of too-stiff suspensions. I was also surprised that there was no squeaking coming from the removable top and its two removable roof panels. The JK's chassis is reputed to be stiffer than the TJ's and the way it handled the pot-holed road with such quiet aplomb testified to that fact.

After a few kilometres, I aired the Goodyear Wrangler SRA (P245/75R16) tires down to 15 psi. This produced a very satisfactory bulge in the sidewalls. We continued on our way, and as the elevation increased, the rutted, muddy road became a hard-crust snow trail. The top layer was about 2 to 3 inches and very hard, with a coarse powder underneath. To maintain our forward momentum, we had to keep the speed up while being rocked side to side as we tried to stay in the deep, frozen tracks left by a tall 4x4, probably the week before. The long wheelbase really helped to keep the fishtailing under control. After a few kilometres of this, I could hear the undercarriage scraping the crust and knew it was just a matter of time before we got high centered. I was quite satisfied with the performance of the JK. While it was able to maintain decent contact pressure on the snow, it kept going. About 200 metres past where the JK got stuck, our chase vehicle (dual transfer cases, dual lockers, and 39.5" IROKs) had quite a bit of trouble turning around. So as you can see, this wasn't exactly a cakewalk. The hard crust, combined with the coarse powder underneath, made for difficult snow conditions. By the way, kudos to Daimler-Chrysler for mounting some decent, and easily accessible front tow hooks on the JK. Because this JK had the towing package, we were able to use the receiver hitch for rearward pulls.

Having had enough of the snow, we headed for lower ground to see how the JK handled rocks and uneven terrain. As expected, the first thing we dragged was the under carriage when we tried to drive through a ditch. The long wheelbase was definitely detrimental to the JK's break-over angle. It wasn't bad enough to stop us from going on any trails that we would expect to take a stock 4x4, but it does require some consideration and due care on the part of the driver. The approach and departure angles, on the other hand, were quite good. My only comment here would be that the front valance should be removed by all new JK owners. It hangs down too low and will soon get hung up on something, particularly when backing up. For that matter, I'd also remove the side steps and replace them with some real rocker armour (like the kind found on the Rubicon package). As I mentioned earlier, the overall gearing on the JK is quite good. It was very easy to control it, which is saying a lot for me, since I haven't 'wheeled a manual transmission in a long, long time.

Because of the recent weather, we also did extensive driving in deep pools of water. The four wheel disc brakes were absolutely fantastic. No worrying about water logged drums when exiting the puddles, and no ABS issues, either. Again, I like safety systems that don't get in my way.

In one of the water logged trenches, I was reminded of why I like flat-sided 4x4s that have protruding wheels. I entered the trench at an off-camber angle so that one side of the Jeep was riding outside of the trench while the other was leaned heavily into it (I was, um, testing the center of gravity, ok?). Anyway, the high side slipped and fell down the near-vertical wall of the trench. Because the tires are the widest part of the vehicle, they kept the sheet metal off the wall and safe from damage. Add some nerf bars on the side and your protection goes up by an even higher margin.

One more thing about water: like the TJ, the JK uses an air intake that doesn't draw air from near the grill, there by reducing the chances of hydro-locking the engine when fording deep water.

After looking at the JK's features and driving on and off the pavement, my conclusion is obvious: I love it. Jeep has made a vehicle that is, beyond a doubt, geared towards people who want to go four-wheeling. In its bone stock configuration, it would satisfy all the SUV-lovers who simply want an all-weather vehicle. For those of us who need something more, I can't imagine a better platform to build on. The JK's weakest points (break-over angle and front bumper valance) are easily addressed by the modifications that most four-wheelers would make such as a lift kit and winch bumper. Its solid front and rear axles make it very easy to lift and obtain impressive suspension travel. The gearing (with the 6-spd manual and 4:10 diffs) is just great and I think it would handle 33" tires easily, and quite probably 35" just fine. Also, to fit 35" tires, you don't need a long arm kit like the TJs required. The JKs use longer lower arms than the TJs which allows them to get away with more lift without displaying the weird handling quirks that necessitated the move to longer arms. So lifting a JK should be cheaper than lifting a TJ the same amount.

Of course, to make things easy, a four-wheeler could simply buy a Rubicon package. It'll have front and rear lockers, 4:1 transfer case gears, rocker armour, the Active Sway Bar system, and enough lift to fit factory 32" tires. A budget boost 2" lift will have you fitting 35" tires very easily and inexpensively.


Like all Wranglers, the front bumper can be easily and inexpensively replaced with one that can support a winch and other accessories. The big plastic fenders were one of my favourite features of the JK.

Approach...

and departure angles were very good, even better than the TJ. As you would expect from the long wheelbase, break over angle suffers.

The four-wheel disc brakes were great for water-logged trails.

Although the JK's turning radius was noticeably wider than a 2-door Wrangler's it was still maneuverable enough for threading between the trees.

The JK did okay on the rocks but we wish we had the Active Sway Bar System here.

The Goodyears did a good job of keeping the bead at 15 psi and flexed pretty well. But if this were our Jeep, the first thing we'd do is put on some tall mud tires.

The Trac-Lok did a great job of keeping us going through the hard-crust snow but finally failed us when we got high-centered.

After a long day on the trail, we drove home with a very favourable impression of the new JK.
Bookmark and Share

 

Jump to the Comments
Recent Content You Might Have Missed

In The News

  • Ford F150 Airbag May Suddenly Deploy, Not As Funny As It Sounds
  • A Garage-Sized Shop Crane
  • A Valve Cap Worth Spending Money On
  • Get Your Geek On With Jeep's Call of Duty: Black Ops Edition
  • Vision X Releases New LED Work Light

Feature

  • Getting Started in Four Wheeling - What You Need
  • Why You Need a Ham (VHF) Radio
  • Cruiser Days 2010
  • KORRBC - Race 2
  • Kamloops Off Road Racing Series

Featured Vehicles

  • Cummins Traveler
  • P40 Warhawk
  • HULK! A heady blend of North American grunt and Mercedes Unimog engineering
  • Chris Olson's Willys Jeep
  • Ben Olson's Air Zuki

Product Review

  • OR Fab Cherokee Armour
  • OR Fab Rear Tube Bumper
  • OR Fab Rock Slider Front Bumper
  • Wheelspacers.ca
  • Napier Precision Heavy Duty Jeep Cherokee Fender Flares

Project Vehicles

  • Project XJ: a New Beginning
  • Hi-Steer Conversion
  • Kilby High Volume Automatic Transmission Pan
  • Bestop Trail Max Aqua Sport Seats
  • Teraflex Revolver Shackles

Trip Report

  • The Elaho Giant
  • Exploring the Britannia Mines - Part 2
  • Exploring Beaverdell
  • Exploring the Britannia Mine and Mt. Sheer Town Site
  • Sylvester Snow Wheeling

Wrenching

  • Fixing the Jeep Neutral Safety Switch (NSS)
  • Fixing A Loose Steering Column In A Jeep
  • How To Re-Assemble Your Drum Brakes
  • Diagnosing a No-Start Condition
  • Winch Rope

Quick Looks

  • Garmin's Oregon GPS
  • SPOT Satellite Messenger
  • Garmin's New Colorado GPS Unit - A Quick Look
  • LEDSupply's Flashlight Upgrade Kits
  • Gilsson GPS Antenna

Vehicle Review

  • 2010 Ram 2500 HD Cummins Crew Cab
  • Jeep Rubicon Test Drive
  • Dodge Ram Mega Cab 4x4
  • Toyota FJ Cruiser Test Drive
  • Diesel Grand Cherokee Now Available in Canada


BC4x4 Main Page
Click to Send Email
to BC4x4
(20-sec delay)
SEARCH
ARTICLES
In The News
Trip Reports
Features
Land Use
Doh!
Photo Album
Videos
Cover Shots
TECH
Project Vehicles
Product Reviews
Vehicle Reviews
Quick Looks
Wrenching
Featured Vehicles
YJ FAQ
Calculators
MARKETPLACE
4x4 Suppliers
Message Board
FOR SALE Ads
WANTED Ads
RESOURCES
Coming Events
Message Board

Except where otherwise noted, all contents on this site are Copyright 1999 - 2019 © 599244 BC Ltd. All rights reserved. No content on this site may be reproduced without express permission from 599244 BC Ltd.
Disclaimer: Activities and vehicle modifications appearing or described on this website and its pages may be potentially dangerous. We do not endorse any such activity for others or recommend it to any particular person - we simply describe our experiences and opinions. If you choose to engage in these activities, it is by your own free will and at your own volition. Use common sense and remember that none of this material is presented as being recommended by a professional mechanic or driving instructor. This information is presented for your amusement only. Do not take unwise risks, consult a certified professional if you are not sure of something. - 599244 BC Ltd. (bc4x4.com) and the authors of these articles assume no liability for how any particular individual chooses to use the information presented here.
Terms of Use
Copyright