What’s So Special about the 1997–2006 Jeep TJ Series?
The arrival of the TJ in the community was fascinating to watch because this new, redesigned Jeep became dominant in such a short amount of time. The YJ and CJ series almost moved into the back seat overnight. The aftermarket experienced a rebirth because this new model required new equipment not yet offered. It also prompted the birth of a new aftermarket with companies specializing in TJ-specific equipment.
Interestingly, because of the JK (the successor to TJ), the TJ has moved into the space that the CJ and YJ found themselves in after the introduction of the TJ. Building and modifying the TJ is becoming easier and more affordable as the used prices for the TJ have fallen. The TJ is destined to become a classic Jeep, just like the models before it.
I’ve been building and modifying Jeeps since 1984 and have been continuously working on my 1978 CJ-5, 2004 TJ Unlimited, and 2016 JK Rubicon Unlimited. These Jeeps have seen many modifications and trail time through the years. They have seen many versions of lift kits, engine rebuilds and modifications, a frame replacement, lockers, tires, wheels, etc. The list goes on and on and is still going. The 2004 TJ Unlimited is a big part of this book and so much of what was done to it aligns with the concepts discussed here.
The suspension redesign on the TJ quickly proved itself off-road. The TJ grew to dominate the off-road in a very short time. With only a minor lift and larger tires, the already-capable TJ could tackle serious trails.
Attending an event that focuses on the Jeep shows how huge a following this vehicle has. The annual All Breeds Jeep Show in York, Pennsylvania, put on by PA Jeeps draws hundreds of Jeeps every year.
Before we begin, I want to stress that safety is the number-one concern when working on your Jeep. Don’t take chances, plan ahead in the work, get help when needed, and be aware of your surroundings. Certain modifications to a Jeep can alter the way it drives. Lift kits and larger tires will affect road handling and stopping ability. Low quality or incorrect components can cause failures, damage, and potential injury. Be safe out there.
Butler, Pennsylvania, is considered the birthplace of the Jeep. It is here that the Bantam car company created the initial design that became the Jeep. The Bantam Jeep Heritage Festival held annually in Butler draws thousands of Jeeps. The Butler Jeep Invasion is one part of the festival where Jeeps line the streets of Butler. It’s a must-attend event for a Jeep lover.
This is the project Jeep that is the subject of much of this book: a 2004 TJ Wrangler Unlimited. This Jeep has proven to be so much fun to work on and drive. It’s common for Jeepers to refer to the TJ Unlimited as an “LJ,” which is an unofficial designation never used by Jeep.
CHAPTER 1
THE WRANGLER TJ, A DEPARTURE FROM THE PAST
In January 1996, Jeep unveiled the new Wrangler at the Detroit Auto Show. This model would replace the Wrangler YJ; its full redesign was a drastic departure from what the line featured for more than 50 years. In 1990, Jeep began development of the successor to the YJ and after six years of development, design, and testing, the new Jeep Wrangler, generally referred to as a TJ, was ready for the public.
Brilliant Suspension Redesign
Along with a body redesign (that was an evolution to the prior models), the most notable change was the introduction of a coil spring suspension, replacing the traditional leaf springs. The coil spring system was based upon the system found in the front of the Jeep Cherokee XJ and in the front and rear of the Grand Cherokee ZJ. The Wrangler’s Quadra Coil suspension system uses upper and lower control arms connected to the frame and the solid Dana front and rear axles. The single-rate coil springs provide minimal friction, free articulation, and smoother operation; they improved the ride in both on- and off-road conditions. In addition, a front and rear track bar retain the axle location while front and rear sway bars control body roll during cornering. The difference in suspension performance from any Wrangler or CJ before was like the difference between night and day.
The new Wrangler looked similar to the previous versions, but the underneath left most Jeep owners staring in disbelief. In the beginning, many old-school Jeep owners criticized many of the new features found on the TJ. In the end, Jeep did not disappoint, and the new Jeep exceeded the previous models in many ways. (Jeep is a registered trademark of FCA US LLC)
The Jeep community, in love with the return to round headlights, was unsure of the new design and many were promising to hold out and not buy a Jeep without leaf springs. Jokes and general resistance to change ended quite quickly after new Jeep owners started putting their new suspensions to the test both on- and off-road. The free-moving design of the coil spring setup allows the suspension to absorb changing road surfaces and navigate obstacles smoothly, efficiently, and exceptionally well. In many and most ways, the coil-spring design is superior to leaf springs.
With the new suspension, both existing companies and many new companies scrambled to create modifications to allow lifts and increased performance. It was evident that the new Jeep could be modified easily to increase off-road performance in a variety of ways, ranging from inexpensive spacers to complex long-arm systems. All of this will be explored in chapter 6. Even with a simple lift and larger tires, the new suspension, which was cautiously received by the Jeep community, shone as a winner for Jeep and off-road drivers.
The Wrangler Quadra Link suspension uses a single coil spring and shock per wheel along with an upper and lower control arm. Weather and time can take its toll with the appearance of the Jeep suspension, but the function remains reliable. Fresh springs and shocks will breathe new life into the Jeep’s ride.
Models and Trim Levels
The new Wrangler brought new models and trim levels to the line, some maintaining the sporty nature of the Jeep while others added a level of class and sophistication, to a very special model designed for the off-road enthusiast.
The Wrangler TJ returned to the iconic round headlights found in similar Jeep models prior to the YJ. For an unusual new look, the TJ moved the turn signal lights from below the headlights to the fenders for better visibility and space.
Models
The Wrangler was available in two main models within its nine-year run: the Wrangler (TJ) and Wrangler Unlimited (TJU). In addition to the new suspension, the TJ featured improved climate control and additional safety equipment such as airbags and anti-lock brakes. The Wrangler TJ shared many specifications of the prior Wrangler YJ, including wheelbase, solid axles, door handles, tailgate, and engines. The redesigned body lowered the grille height and increased windshield angle to improve aerodynamics and fuel efficiency.
A complete 3-inch lift kit from TeraFlex for the TJ that includes lift springs, tuned shocks, sway bar disconnects,