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2007 Jeep JK Wrangler

Passegner Side View
Rick Péwé | Writer
Posted April 1, 2006
Photographers: Courtesy of Jeep

The exclusive secret photos and facts!

You knew it would happen, and you knew it would be this year. What you had also hoped for is that Jeep didn't ruin the new Wrangler (designated internally as JK) or undermine any of its off-road ability and heritage. Luckily for you and us, the new Jeep has its soul firmly in the past, while still looking toward the future. We haven't had a chance to drive it yet, but we got this exclusive deep dive into the mechanics and design of the JK, just so you'd be prepped when the first models roll off the assembly line this fall. Sure, we'll give you driving updates when they're available, but the secret hot smoke and dope is here now for us to share with you. Bottom line: The new Jeep Wrangler is bigger and beefier, with many upgraded components which should make it even a better wheeler, and a much better road machine. Check it out.

First off: It still looks like a Jeep. Since first impressions are usually the ones that stick, the Jeep design crew knew to keep the round headlights, seven-slot grille, trapezoidal wheel arches, and open body configuration, along with a fold-down windshield. Of course in the ever-increasing quest for better fuel economy and pedestrian safety, the grille has been laid back and the windshield is now slightly curved. We'd rather pay more for fuel and whack a few pedestrians off the trail, but hey, overall the look ain't bad. It's full-on what the Jeep Gladiator concept looked like when revealed at the 2005 Detroit Auto Show, with big external door hinges and a sloped-back grille. In addition, the big flexible fenders are designed to cover the tread, but be removable for customization. Other design cues from many a show vehicle including the Jeep Rescue have made their way onto the new JK as well, with more exciting revelations yet to come. But looks aren't everything, and compared to the current TJ Wrangler, the JK is 5 inches wider with only a 3 1/2-inch-wider track, and 5 1/2 inches longer with a 2-inch longer wheelbase (95.4 inches) for this two-door, so it still looks proportional in a Jeep sort of way. Somehow this increase in overall heft (about 300 pounds) still allows for a 44.3 degree approach angle, 25.4 degree breakover angle, and a 40.4 departure angle on the new Rubicon Wrangler, which, through a combination of taller tires and moving the gas tank forward, rivals today's Rubicon Wrangler at 49, 25.4, and 33.9! And finally, what can you say about the blow-molded bumpers, other than they're flexible and removable? 'Nuff said!

Mechanically, the biggest news is the 3.8L V-6 engine replacing the venerable 4.0L straight six, a holdover from some 35 years ago. While strong, torquey, and reliable, the old 4.0L couldn't meet current or future smog rules, weighs much more than the V-6 replacing it, and makes designing frontal impact parameters very difficult. Our biggest concern will be the torque band of the engine, previously used in the Pacifica and Caravan. The old 4.0L develops 190 hp at 4,600 rpm and 235 lb-ft at 3,200, while the V-6 gives 205 hp at 5,200 and 240 lb-ft at 4,000. This means you get a higher revving engine that won't match the low-end torque of the inline six, so some sort of gearing compromises will have to be made. No more engine lugging like a tractor with your Jeep, but spinning the tires in the sand and mud will be much more fun! But gone too is the mechanical throttle cable, as this new generation is a drive-by-wire, allowing a multitude of safety and engine management functions to be applied. And if you're looking for a four-cylinder, don't bother, unless you go overseas where a diesel 2.8L VM is available, even though they would sell like hotcakes here.

Another major change is the 32-inch BFGoodrichs instead of Goodyears on the Rubicon model. While they are still load range E with too much air in them for our uses, the BFGs provide better wet weather traction and quieter operation in this application. They are available in the 17-inch size, while the Wrangler X and Sahara get 16-inch Goodyears, and the Sahara has the option of Bridgestones on hideous 18s. We just hope we don't see any of those, or have to test them. And in case you didn't notice, the wheel pattern has increased on all Wranglers to a 5-on-5-inch bolt circle. Someday, they may get back to the 5-on-5 1/2 like they should!

Major internal changes are extremely important and are buried in the axles. The Wrangler X and Sahara get a Dana 30 front and a Dana 35 rear, and the optional towing package nets you a rear Dana 44 as well. A Trac-Lok limited slip is optional on the 35 and 44, with 3.21 and 4.10 gear ratios available. The 35 is now a non-C-clip captive bearing style, with stronger shafts, strengthened tubes, and bigger pinion bearings and pinion. The front 30 has bigger pinion and pinion bearings and bigger axle joints and stub shafts, and also features a captive unit bearing so the stub axle can be removed if needed. And since bigger is better, the Rubicon's 44 front is now a reverse-pinion design, has stronger tubes, a bigger pinion shaft and bearings, bigger 1350 series U-joints, better axles, and a captive unit bearing. The Rubicon's rear 44 features bigger pinion bearings and pinion, a larger (yes, larger) ring gear by 10 mm, bigger tubes, and (gasp) 32-spline 1.4-inch-diameter special axleshafts. That stuff will keep the aftermarket busy for a while, and, oh yeah, the completely new-style lockers front and rear are now engaged magnetically, instead of vacuum operated. Less is better in this case. Did we mention the drain plugs? Find that in another vehicle....


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