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A former AMC engineer critiques the Jeep Liberty

by Evan Boberg, former Chrysler and AMC suspension engineer

Though I personally had little to do with the Liberty, I know well the people that designed it. I'll offer my opinion as to why DCX missed the mark so badly.

In my book Common Sense Not Required, I wrote an entire section about my experiences designing Jeeps. From these efforts came the 1997 Wrangler (TJ) and the 1999 Grand Cherokee (ZJ). The Liberty (KJ) was just beginning to evolve and I was booted from the department before much was done.

Probably the greatest defender of the Jeep heritage at Chrysler was Bob Bachelor, a longtime engineer, who joined AMC after retiring from Chrysler twice. Bob passed away less than six months after I had been booted from the department. Other defenders of the Jeep heritage were also booted or left in disgust. There were no defenders of the Jeep left in the advanced design department.

Let me start by briefly reviewing some aspects of the history of Jeep:

Willys and Kaiser established the Jeep brand, and AMC took over in 1970. AMC upgraded the line with their own engines and some other improvements; however, no new vehicles were designed, except the Hummer at the AM General division, which built vehicles for the military. In 1978, Renault purchased a controlling interest in AMC; AM General was sold because the military would not buy vehicles from a foreign controlled manufacturer. Ironically, GM capitalized on the design originally done by Jeep under the AM General banner.

The Cherokee was a groundbreaking vehicle that never was duplicated by any other manufacturer. Like the minivan, the Cherokee was kind of an accident. In the late '70s, after the oil scares, all the North American auto companies embarked on redesigns to downsize their products. SUVs were not a significant segment of the market, and their downsized versions were slow in coming. Essentially there was the Ford Bronco, Chevy and GMC Suburban and Blazer, Dodge Ramcharger, and the Jeep SJ Cherokee and Wagoneer. These vehicles were all adaptations of a truck, and with the exception of the Suburban and Jeeps, had few parts that were unique to the SUV.

GM and Ford downsized their pickup trucks and soon followed with the SUV versions which followed the same pattern; adaptations of the compact trucks, thus smaller two-door versions of their larger two-door SUVs. Chrysler didn't even bother, and bought vehicles from Mitsubishi to fill this market. The Japanese SUVs were also adaptations of trucks.

At Jeep, they didn't sell many pickup trucks. When it came to doing a downsized version of their SUV, they designed an SUV first. Renault provided the cash, and the Cherokee was born. The Cherokee was the only SUV that was not an adaptation of a truck. Therefore, it had many advantages over the truck based SUVs. The most significant was that a four door version was designed from the start.

Trucks use body-on-frame construction with few exceptions (VW and Jeep Commanche). The Cherokee uses uni-body construction, like most passenger cars. The net result is a very strong, lightweight body. Renault doesn't know how to sell cars in the US, but they do know how to build lightweight car bodies. In my book, Common Sense Not Required, I cover in depth the advantage of the Jeep Link/Coil suspension. One significant advantage, it is lightweight.

It was not until the mid-1990s that other manufacturers designed purpose built SUVs. Even these designs did not duplicate the advantages of the Cherokee; they would not copy such a "retro" suspension design.

In 1991, AMC had planned to replace the Cherokee with what became the Grand Cherokee. The merger with Chrysler changed these plans. The Grand Cherokee got delayed while it got a brand new assembly plant on Jefferson Avenue in Detroit. Cherokee sales remained strong, along with the strong sales of the new Grand Cherokee.

When I say the Cherokee was never duplicated by any other manufacturer, I don't mean it was never duplicated. The Grand Cherokee was an improvement to the Cherokee and both were profitable for Chrysler.

The Cherokee and Grand Cherokee remained significantly lighter than the competition. The Cherokee, fully loaded with options, had a curb weight of 3380 lbs. The Grand Cherokee (1992-98), fully optioned with the 5.2L V-8, had a curb weight of 3936 lbs. A base model Ford Explorer, powered by a V-6 weighed [at the time of writing] about 4300 lbs. Other American and Japanese built SUVs have curb weights about the same as the Explorer.

Ford engineers could not believe the lightweight Grand Cherokee would be durable, so they ran one on their durability test assuming it would fall apart. Some of their engineers confessed privately that it was, in fact, superior to the Explorer.

Enter the automotive press. With Chrysler backing Jeep, Cherokees and later Grand Cherokees outsold all the competition. The press ignored this and always criticized the Jeep for its "dated" suspension design, while praising it for its superior ride, performance, and handling. They praised Chrysler engineers for being geniuses, because they made the retro design work so well. They never wrote that the "dated" design might have been responsible for the superior performance. Everyone "knows" that an IFS is superior.

When I joined AMC, one of my personal goals was to modernize the Jeeps with an IFS. Then I met Bob Bachelor. As I discuss in my book, Bob taught me about the many advantages of the Jeep Link/Coil suspension. Not that it is the best suspension for every vehicle, but it is the best suspension for a compact SUV.

In the world of technology, it is common to believe the new design is always an improvement. Bob opened my eyes. In the application of a compact SUV, the "retro tech" was superior. It wasn't perfect, but it was better than an IFS. In other applications, the IFS may be superior.

Some other examples where "retro tech" is superior: Gas powered cars vs. electric. I've become a talk radio junkie and watch little television. If you believe my book, hybrids with their "gee whiz" technology don't actually get better gas mileage for most drivers.
This one really cracks me up; the Segway Human Transporter: For about $4000, you get a funky scooter with gyroscopes and computers to keep it from falling over; when it has a charge in its batteries that is. At AutoZone, you can pick up a more conventional looking electric scooter that uses the human rider to keep it from tipping over for $100.

Jeeps from the beginning were unstoppable. Rain, snow, mud or mountains cannot stop them. So even when quality was poor, they were in demand. Willys and Kaiser established this heritage with the CJ and SJ lines. AMC didn't mess with it.

Renault brought it to a new level with the Cherokee, a purpose built compact SUV. Chrysler continued with the release of the Grand Cherokee and fixing the Wrangler back to its heritage with the TJ. Though Bob Bachelor was a Chrysler guy, he was smart enough to see the advantages that the Cherokee possessed, and constantly reminded Chrysler executives of these advantages.

The press continued to ridicule the Jeeps for their antique suspension designs, while praising them for their outstanding performance. The Grand Cherokee for '99 stayed pretty true to its heritage, primarily because Bob lived long enough to influence it. I had received the boot and could no longer influence it.

Then Toyota introduced the RAV4. The automotive press raved and praised it. Toyota's line of SUVs before the RAV4 had consisted of truck adaptations and a clone of an old Jeep (the Land Cruiser). With all the praise heaped upon the RAV4, all the auto manufacturers around the world rushed to clone it. The Liberty is one of these clones.

Here in Utah, I don't often see a RAV4 or one of its clones on the road. I do see Cherokees in great abundance, including the '98 and newer restyled ones. Chrysler and the new Daimler/Chrysler minions ignored the Cherokee's success and succumbed to the ravings of the automotive press and tried to clone the RAV4 to replace the Cherokee.

The Liberty is a RAV4 wannabe. For a RAV4 wannabe, it's really quite good. What really baffles me is its weight; it's nearly 1,000 lbs heavier than a similarly equipped Cherokee. It uses uni-body construction. If it was body-on-frame, that would explain the weight gain. An IFS will add weight to a vehicle, but 1,000 lbs? Maybe, if they had done an IFS with torsion springs, but this IFS used coil springs in a fashion that I would approve of.

I looked under one the other day and spotted a huge mass damper on the rear axle (a typical Ford band-aid for a crappy design). Maybe it's a Ford design.

One more little diversion: I took a little dig at IFS suspensions with torsion bar springs. This is probably the heaviest suspension design one can do, because the supporting structure around it has to be the strongest. Bob Bachelor designed this type suspension for Chrysler in the 1950s and spent the rest of his career trying to get Chrysler to abandon it. Not only was it heavy, it was difficult to isolate the road noise in a uni-body car (most of what Chrysler built). On the plus side, it was easier to tune for stock car racing and may have helped Petty win a few races.

Back to the Liberty. It's got round headlights and a TJ looking grill, but nothing else separates it from the competition. DCX succumbed to the Japanese loving automotive press and replaced a very successful old design with a RAV4 wannabe. DC has blown their first challenge to preserve the Jeep heritage. That's my two cents worth.


  1. How the Jeep Liberty factory was designed
  2. Allpar's Jeep Liberty Limited review
  3. Allpar's Jeep Liberty Renegade review
  4. Guest editorials on the Jeep Liberty
  5. Jeep Cherokee/Liberty forum

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