OK, so we'll get this overwith right away for all of you die-hard solid axle lovers out there. The solid front axle is gone. Bye bye. See ya' later. Yes, yes, we can hear you groaning out there.
But hear us out for a minute, if you will. First of all, Jeep already gave in to IFS on the Liberty and through our own testing, we determined that it wasn't a completely awful thing to do. Sure, it doesn't flex like a solid axle does, but the fact is, folks driving these Jeeps rarely or never off-road them anyway. So let's face it - everyone knows IFS rides better on the road. Why do you think just about every car, truck and SUV on the market has IFS? That's right. IFS handles better on the road - where the vehicle will spend most of its life.
I bet you can count on one hand the number of times you've ever seen a WJ Grand Cherokee on a serious trail. I know I can. So what does it matter anyway? I personally own a WJ that my wife and I drive on the road every day. Honestly, I am welcoming many of the upcoming changes with open arms.
Jeep is getting beat in the SUV marketplace and one of the reasons is that their top-of-the-line model currently just doesn't drive comparably to its competition. Of course, Jeep stands for off-road capability - we all know that, and Jeep hasn't forgotten, either. But the business case was made to make the change and they are going at it full-guns.
So now that that's overwith, we can tell you the good news. Though IFS can't perform like a solid axle off-road, the new Grand does actually have 15mm more travel than the outgoing WJ (225mm total). Rear travel is the same at 252mm. In addition, the all-new aluminum knuckles are tucked way inside and way up high to give maximum clearance.
Axles are both corporate versions (no more Dana). The front ring gear on the 4x4 models measures 7.9". The rear axle remains solid with an 8.3" ring gear.
Jeep has a whole new bag of tricks up their sleeves in the suspension department. The rear is now a 5-link setup and has more vertically situated shocks.
Up front, the Grand now has an all-new short and long arm setup which uses single-piece nodular iron control arms. These provide higher ground clearance than most IFS systems and coil-over shocks are now used for better performance.
Plenty of acronyms are used on the new Grand, which seems to be mandatory these days. ABS braking is standard and Brake Traction Control Systems (BTCS) helps to manage torque between wheels on the same axle when wheel slip is detected. BTCS is available on models with full-time 4x4. Electronic Stability Control (ESP) is also on-tap for taking over the controls on the road when the vehicle seems to be out of control.
If you're into 4 wheel drive (cough cough) then the new Grand has three flavors to choose from. Quadra-Trac I is your basic all-wheel-drive system and is included with the 3.7L engine. The NV140 transfer case can send traction to any wheel that needs it at any time and there is no low range. BTBC is used to help control the wheels in slippery situations.
Quadra-Trac II steps things up a bit and uses the NV245 transfer case which is used along with the 4.7L and 5.7L engines. The NV245 features a 2.72:1 low range, which is activated by an electronic lever in the cab. BTCS is also used with this system. One interesting byproduct of using an electronic lever, is the e-brake lever is now on the "correct" (left) side of the transmission shifter.
Quadra-Drive II is the pinnacle of the 4WD systems. Quadra-Drive II is a full-time four wheel drive system that uses lots of techno-wizardry. Developed by Eaton, Electronic Limited Slip Differentials (ELSD) are used in both the front and rear axles. Like the name would suggest, ELSD uses electronic sensors to vary the clutch packs in each axle to allow them to differentiate from full differentiation to full lock. In other words, 100% power can be sent to one wheel if it is needed. Couple this with the ESP and DHS and you have a lot of technology at hand (and a lot of acronyms to keep up with).
What's DHS? DHS is a new Dynamic Handling System. Essentially, it is a hydraulically-controlled active stabilizer system. Available only on the 5.7L models, DHS taps into the upgraded power steering system and adjusts how the front and rear anti-sway bars react to the road.
We were shown a video of DHS being tested on a WJ going through sharp curves. It was amazing. The Jeep without DHS leaned heavily while the DHS-equipped Jeep remained close to level with the road. In 4LO, the system is deactivated and the system is "loose." We're not sure how this will work off-road but it looks to be a real winner on-road. Future test drives will surely tell.
What's powering the Grand Cherokee? If you were reading carefully, you will have noticed a 3.7L and a 5.7L mentioned.
The 3.7L 6-cylinder comes from the Liberty and replaces the outdated 4.0L that has been a staple in the Jeep line for years. The V6 provides 210 horsepower @ 5200 rpm and 235 lb-ft of torque at 4000 rpm. A revised cam and new valve lash adjusters are used to improve the engine at idle. A new thick-wall manifold is also new for 2005. V6 models are backed by a W5A580 five-speed overdrive transmission with 3.07:1 differential gears.
The current 4.7L SOHC V8 has been updated and now produces 230hp @ 4700rpm and 290 lb-ft of torque at 3700 rpm. Dual knock sensors have been added to improve fuel economy and power.
The king of the road, of course, is the 5.7L HEMI engine. By now you've heard all the hype from the Dodge boys but now the HEMI is going in its first Jeep. Cranking out 325 hp @ 5100 rpm and 370 lb-ft of torque at 3600 rpm, the HEMI is the engine of choice for the power-hungry and those interested in using their Grand for towing duty.
In response to tighter emissions regulations and pressure from both the Government and the public, the HEMI features the Multi-Displacement System (MDS). MDS works seamlessly and unnoticeably as the driver goes down the road. At times when the Jeep is cruising and power is not needed, half of the cylinders are deactivated. Immediately upon receiving throttle input, all 8 cylinders are brought back to life. This is done with the help of a new Electronic Throttle Control (ETC). Transitions between 4 and 8 cylinders happen within 40ms (40/1000ths of a second).
Both the 4.7L and the 5.7L HEMI send power to a 545RFE multi-speed automatic transmission. Differential ratios are 3.73:1.
Obviously, we'll need to get our hands on a new Grand to see how all this new-fangled techno stuff will turn out in the real world. On paper, anyway, the Grand has really stepped up to the plate in terms of both technology and style. We think that the many improvements found throughout the WK are exciting from a grocery-getter and family-hauler standpoint. Like we said earlier, most of the four-wheeling the Grands will ever see will be in the snow, mud, and the occasional dirt road, so we're not too concerned about the change to IFS.
Many people have criticized Jeep for giving in to the new corporate parents, but the new Grand Cherokee appears to be one reason to embrace change. What has become a run-of-the-mill SUV in today's market is going out and an exciting all-new replacement is ready to hit the road running. We can't wait to see how it all turns out.
Initially, only Laredo and Limited models will be available, but Jeep is known to release special editions throughout the model years. Expect the new Grands in showrooms in the Fall.