You may not have heard the name Roy Lunn, but undoubtedly you’ve heard about the cars that he guided into being. You think that’s an exaggeration? Well, you’ve heard about the Ford GT40 haven’t you? How about the original XJ Jeep Cherokee? Lunn headed the team at Ford that developed the LeMans winning GT40. Later as head of engineering for Jeep (and ultimately VP of engineering for AMC) he was responsible for the almost unkillable Cherokee, Jeep’s first unibody vehicle, a car that remained in production for over two decades with few structural changes and could be said to be the first modern SUV. In addition to those two landmark vehicles, Lunn also was in charge of the engineering for two other influential cars, the original two-seat midengine Mustang I concept and the 4X4 AMC Eagle. If that’s not an impressive enough CV for a car guy, before Ford, he designed the Aston Martin DB2 and won an international rally. After he retired from AMC, he went to work for its subsidiary, AM General, putting the original military Humvee into production. Oh, he also had an important role in creating one of the most legendary muscle cars ever, the Boss 429 Mustang. So, yeah, you should know about Roy C. Lunn. (Read More…)
Tag: Jeep Cherokee
The problem with a “take-no-prisoners” approach to evaluating new cars is that when you’re the only one adopting a particular stance, it can get pretty lonely – even your own readers begin to doubt you. My initial review of the Jeep Cherokee was a great example of this. Most reports are fairly positive – and indeed, there was plenty to like about the car, as my own review mentioned – but many of the car’s flaws were glossed over or simply not mentioned. On the other hand, we at TTAC gave you the unvarnished truth about the Cherokee – and Chrysler was gracious enough to let us review the Cherokee again.
A TTAC reader is an engineer with a major powertrain company, and offered his extremely detailed analysis of the ZF 9-speed. Consider this an AP level course in powertrain engineering.
Before we dive right in to the 9-speed gearbox, let’s take a quick refresher on the basics of gears. The simplest gear set consists of 2 parallel gears mounted on 2 parallel shafts. Shown in Fig.1 is a gear set with a 20 tooth drive gear on the right and a 30 tooth driven gear on the left. For this gear set the speed of the driven gear is 1.5 times lower than the drive gear, and assuming no frictional losses anywhere, the torque on the driven gear is 1.5 times higher. This gear set has a ratio of 1.5:1. This type of a gear set is usually not favorable for packaging since it requires 2 parallel shafts, and there are largest separating forces that push the 2 gears apart which means that the bearings supporting the shafts have significant radial loads on them, in addition to an axial load if the gears are helical.
The folks at Jeep have known for some time that high volume on-road models have to be part of the mix to keep low volume off-road models viable. From the 1946 Willys Station Wagon and the original Wagoneer, to the Grand Cherokee and the Compass, Jeep has been on a steady march towards the word no Wrangler owner wants to hear: “crossover”. Their plan is to replace the off-road capable Liberty and compete with the RAV4, CR-V and 20 other small crossovers with one vehicle: the 2014 Cherokee.
With two ambitious (and contradictory) missions and unconventional looks, the Cherokee has turned into one of the most polarizing cars in recent memory. It is therefore no surprise the Cherokee has been getting mixed reviews. USA Today called it “unstoppable fun” while Consumer Reports called it “half baked” with a “choppy ride and clumsy handling.” Our own Derek Kreindler came away disappointed with its on-road performance at the launch event, though he had praise for the Cherokee’s off-road capabilities. What should we make of the glowing reviews, and the equally loud dissenting voices?
In late 2013, TTAC was invited to review the Jeep Cherokee. As the journalist assigned to cover the launch, I gave what I felt was a nuanced but critical assessment of the vehicle: that it delivered with respect to its off-road prowess, but left a lot to be desired in other areas, namely the on-road driving experience and overall packaging.
TTAC was alone in its criticisms, with other outlets heaping praise on the Cherokee for attributes that I felt were lacking. A backlash from readers, Mopar fans and other entities ensued, and we were left looking like a fringe element of anti-Cherokee cranks, despite what we as an organization felt was a fair and nuanced, if – ahem – slightly colorful review of the car. It turns out that in the end, we weren’t alone.
In a week we will post our first full review of the all-new and all-controversial 2014 Jeep Cherokee. The new Jeep isn’t just raising eyebrows for the love-it or hate-it styling. Or the resurrection of the Cherokee badge. Or the constant delays in production. Or the transverse mounted engine. Or the lack of solid axles. None of that laundry list seems to cause as much discussion around the automotive water cooler than ZF’s 9HP 9-speed transmission. Click past the jump for a deep dive into the tranny with more speeds than my bicycle. If you don’t want to explore transmissions in detail, don’t click. You have been warned.
With the first month of 2014 sales nearly wrapped up, we’ll soon get our first look at how the Jeep Cherokee has fared, following the initial shipment of delayed units. Much has been made of the Cherokee selling 10,000 units in November and 15,000 units in December: it was a great storyline for Chrysler to promote in the run-up to NAIAS, and one for the hometown media (in both Detroit and Toledo) to rally around. Left out of the cheerleading was the fact that these figures accounted for the 25,000 units reportedly sent to dealers in one fell swoop. Can you say “pent up demand”?
But even if the Cherokee continued to sell at that pace – say, 15,000 units per month as an optimistic projection, where would that place it in the larger picture of the small crossover segment?
Mircea Gradu, who had headed Chrysler’s transmission, powertrain and driveline engineering since 2011, left the company to pursue other interests, according to a company statement released last week. Part of Gradu’s responsibilities were the development and launch of the new Jeep Cherokee’s innovative all wheel drive system that can allow the rear axle to freewheel to save fuel. That launch was delayed when 25,000 assembled Cherokees were held back from dealers while engineers recalibrated the software that controls the powertrain and then tested the vehicles. The same basic drivetrain components are planned to be used in a number of other Chrysler group vehicles, starting with the all new 2015 Chrysler 200 introduced last week at the Detroit auto show. (Read More…)
The folks at Allpar have discovered an undisguised Chrysler 200 driving around sans camo. Looking like a cross between a Dart and a Chevrolet Impala, the 200 will use the same CUSW architecture as the Dart and Jeep Cherokee, along with the 2.4L 4-cylinder and Pentastar V6 engines.
Remember the Fiat Viaggio, the Dodge Dart clone that was supposed to be the brand’s breakthrough product in China? The compact sedan has missed its sales targets by as much as 60 percent, and now Fiat is hoping that local production of the Jeep Cherokee can help fill some of their plant’s capacity and capitalize on China’s insatiable demand for crossovers.
Jeep Cherokee units keep piling up at the Toledo, Ohio factory, as Chrysler attempts to iron out production issues, but according to Yahoo Autos, none have been delivered yet.
We live in an era of instant gratification. We want everything, right now, done perfectly, right away. A consequences of that is that delays, even when legitimate, are seen as a sign of incompetence, slow movement and an inability to get things done. In many cases, it’s true. But that doesn’t mean we should pillory Chrysler for delaying production of the Cherokee again.
Chrysler has decided to delay production of the Jeep Cherokee again as the company seeks to iron out further quality issues with their crucial new product.
There may not be a more important car launched this year than the Jeep Cherokee. A symbol of the union between Chrysler and Fiat, designed to lead Jeep’s push into the booming global crossover market, a bold new styling direction for the brand – these elements are all inextricably bound with the vehicle itself, with the Cherokee’s success in the marketplace vindicating all three. Predicting how well a vehicle will sell is always a crapshoot. I try to refrain from forming opinions of vehicles before driving them, but I couldn’t help but root for the Cherokee a little. It had sufficiently angered the Internet Product Planning division with its out-there styling, car-based platform and bold claims of off-road superiority. Charmed by the sheer gall of its contradictory mission (a CUV that can hang with true SUVs off-pavement), I wanted it to be a good vehicle on its own and succeed in the marketplace.