Jeep Wrangler (JK)
The Jeep Wrangler is the third generation of the Jeep Wrangler off-road vehicle. The Wrangler was unveiled at the 2006 North American International Auto Show in Detroit, the JK series 2007 Wrangler Unlimited at the 2006 New York Auto Show.
The car's body and chassis were completely redesigned during the era when Jeep was part of DaimlerChrysler. Just like the Willys MB, the CJ Jeeps and the Wranglers before it, the JK continues to have a separate body and frame, rigid live axles both front and rear, a fold-flat windshield, and can be driven without doors. Also, except optional 4x2 models, the Wrangler JK continues to have part-time four-wheel drive systems, with the choice of high and low gearing.
In addition to the traditional 2-door Jeep, the JK introduced a factory standard four-door model, called the Wrangler Unlimited. Contrary to the first, TJ-based Unlimited, and the CJ-8 "Scrambler", its wheelbase is stretched by 20 instead of 10 inches. The Wrangler Unlimited became a big sales success — by mid-2017 three-quarters of all new Wranglers listed for sale were four-door models.
Development
In 2001, DaimlerChrysler commissioned development of a TJ successor under the "JK" program code for the third-generation Jeep Wrangler. Design work began almost immediately in 2001, with Mark Moushegian winning an internal design competition against Dan Zimmerman by the second quarter of 2003. In January 2004, the JK design was frozen at 31 months ahead of production, and work began on a conceptual preview.On November 16, 2004, Jeep released 2 CAD renderings of a Jeep pickup. On December 5, 2004, the 2005 Jeep Gladiator Concept was unveiled ahead of its January 2005 Detroit Auto Show debut, previewing many of the design elements on the incoming JK. The Wrangler JK was introduced at the 2006 North American International Auto Show with past Chrysler group CEO Tom LaSorda driving one up some steps and through a plate glass window, just as Robert Lutz had done at the show in January 1992 with the Grand Cherokee.
Initial release
The JK was first available for purchase with the 2007 model year, beginning in August 2006. The 2007 model year brought a complete redesign of the Jeep Wrangler, and also a four-door model. The TJ chassis was replaced by an all-new JK platform.The JK Wrangler has been offered from the start in two models:
- A short-wheelbase 2-door, in X, Sahara, and Rubicon trim levels.
- A long-wheelbase Unlimited 4-door, also in X, Sahara, and Rubicon trim levels.
The JK runs almost all vehicle functions, other than steering, under computer software control. Engine, transmission, and to some extent braking are computer-controlled, as are lights and auxiliary systems. This is a first for the Wrangler. As of mid-2007, there have been three safety recalls for software fixes.
Stability control was a new safety feature for the JK Wrangler. All versions offer off-road tuned Anti-lock braking system and traction control system with electronic limited slip differential. Standard on the Rubicon trim is a new electronic sway bar disconnect system.
A Sunrider convertible soft top is standard equipment. Also available on the JK model is an optional 3-piece modular hardtop. Although the doors can still be removed in traditional Wrangler fashion, power windows and remote power door locks were offered for the first time in a Wrangler. Another first is an available navigation system. This is the first generation of the Jeep Wrangler to have a change in the taillamps.
New features included power windows, remote power door locks, navigation, as well as electronically detachable sway bars on some models.
JK Wrangler Unlimited
The JK series 2007 Wrangler Unlimited was unveiled at the New York Auto Show on April 12, 2006. It is stretched even more than the TJ model and features four doors. This change made it the last-remaining 2-door SUV in North America to gain a four-door option and made it the only four-door convertible in production. A full was added to the JK Wrangler's wheelbase. It hit the production line in August 2006 and was priced at $21,000.The Unlimited has the same engine and transmission choices as a short-wheelbase JK. X and Sahara trims offer an option of 4x2 rear-wheel drive in the US. The optional 4x2 was discontinued after the 2010 model year for the Unlimited. 4-wheel drive became standard for the 2011 model year. After the Hummer H1 was discontinued in 2006, the JK Wrangler Unlimited was the only four-door convertible available in the US until the new Ford Bronco came out in July 2021.
The Unlimited offers more options and equipment than any previous Wrangler model, including standard electronic stability program and optional seat-mounted side airbags, remote keyless entry, navigation system, and Sirius Satellite Radio. The navigation and satellite systems are a part of the MyGig Entertainment system that also has a hard drive allowing for the storage of MP3 music files and pictures.
The Wrangler Unlimited became a big sales success — by mid-2017 three three-quarters of all new Wranglers listed for sale were four-door models.
Trim levels
The Standard Wranglers are available in six trim packages. The Unlimited Wranglers are available in four trim packages. Most packages can be ordered with either a hard or soft top, full or half doors.The Sport base model is available in 2-door versions. It is the "bare bones" Wrangler that can be customized to a buyer's specifications by adding such options as air conditioning and other accessories. It was originally called the "Wrangler X" until 2009. Later, stain-resistant YES Essentials cloth seats replaced standard vinyl seats, an AM/FM stereo with single-disc CD/MP3 player and auxiliary audio input jack, and a full-sized spare tire and wheel came standard on this model.
The X-S model features 32-inch tires, air conditioning, fog lights, cruise control, driver’s seat height adjuster, removable doors, and a fold-down windshield. It can be customized to a buyer's specifications, adding such options as power windows and locks, soft or hard top, rear LSD or locker, and other accessories. It was renamed "Sport S" in 2009. Advantages over the Sport included standard air conditioning, alloy wheels, a matching spare tire and wheel, YES essentials stain-resistant cloth seats, optional Uconnect touch-screen radios, optional seven-speaker premium sound system with subwoofer, and optional power equipment, such as power door locks and power windows, a first on any Wrangler model.
The Sahara model is the "luxury" model offering accessories such as body colored fenders, "Yes Essentials" seats, power windows and locks and a 7 speaker infinity sound system with subwoofer, later, with Uconnect 430, among others. It also offered exterior-color fender flares, a paint-matched hard-top, and a gold 'SAHARA' decal on both front fenders.
The Rubicon is the "off-road ready" model, offering 32in BF Goodrich Mud-Terrain KM off-road tires with aggressive tread, seventeen-inch alloy wheels, and more. 'RUBICON' decals adorned both sides of the hood.
The Rubicon package is the dedicated "Offroad" package. Standard components of the Rubicon package include front and rear next generation Dana 44 axles with electric lockers, Rock-Trac four-wheel drive with 4:1 transfer case, rock rails, 32-spline rear axle with an 8.8-inch ring gear, 4.10 axle gearing, electric releasing sway bar, "Yes Essentials" seats, 7-speaker infinity sound system, and any other available option can be added.
Powertrain
A 3.8 L EGH V6 with a displacement of producing and of torque was the base engine in 2007-2011 models. It replaced the AMC 242 straight-6, and was shared with the first-generation Chrysler Pacifica crossover, and Chrysler Town and Country, Dodge Grand Caravan, and Volkswagen Routan minivans. Transmission choices included a standard six-speed Chrysler NSG370 as the manual transmission, or an optional Chrysler Ultradrive 42RLE 4-speed automatic transmission.For the 2012 model year, the 3.8L V6 was replaced by the Chrysler 3.6L Pentastar VVT V6 engine previously seen in the Jeep Grand Cherokee, now producing 285 horsepower and 260 pound-feet of torque. The NSG370 remained as the manual transmission option, while the 42RLE was replaced by a 5-speed Mercedes-Benz NAG1-family W5A580.
The RA428 2.8 L VM Motori turbodiesel straight-4 producing and of torque used in the Liberty KK and Dodge Nitro was offered as options outside of U.S., as it did not satisfy U.S. emission control standards for 2007. It was offered with either the NSG370 manual, or the 5-45RFE automatic transmission. In 2011 engine diesel was upgraded to A428 DOHC producing 200 PS ; torque: Manual transmission: 410 N⋅m automatic transmission: 460 N⋅m and automatic transmission was replaced by a 5-speed Mercedes-Benz NAG1-family W5A580.
The lower two levels have the Jeep Command-Trac part-time four-wheel drive system with an optional Trac-Lok limited-slip differential, while the Rubicon uses Rock-Trac, a version of the NV241 with a 4:1 low range. Electronic locking front- and rear-axles called Tru-lok are also standard on Rubicon models.
| Engine | Year | Transmission |
| 3.8 L EGH | 2007–2011 | 4-speed 42RLE automatic |
| 3.8 L EGH | 2007–2011 | 6-speed NSG370 manual |
| 3.6 L Pentastar | 2012–2018 | 5-speed W5A580 automatic |
| 3.6 L Pentastar | 2012–2018 | 6-speed NSG370 manual |
| 2.8 L RA 428 | 2007–2010 | 5-speed 545RFE automatic |
| 2.8 L RA 428 | 2011–Present | 5-speed W5A580 automatic |
| 2.8 L RA 428 | 2007–2015 | 6-speed NSG370 manual |