at Bishop Racing Products (BRP); Steve Dowden at Hi-Lift Jack Company; Steve Roberts at Advance Adapters; Wilfred Eibach, Mark Krumme, and Julian Gill at Eibach; John Apogee at Banks Power; Willie Woo at Mickey Thompson Tires; Brandon Erickson; John Stewart; and Dwain Williams.
CHAPTER 1
JEEP WRANGLER YJ
The first Jeep to use the name Wrangler was the YJ in 1986 for the 1987 model year. The most distinguishing features of the YJ were the rectangular headlights and the bend midway up the grille. Today, many YJs have been upgraded to become first-class trail rigs.
In 1986, American Motors Corporation (AMC) launched the first Jeep Wrangler: the 1987 YJ. The Wrangler YJ replaced the CJ7 and was in production through the 1995 model year. While the history of the YJ provides interesting reading, looking at how the YJ fits into the current Jeep world is the first order of business.
According to some Jeep engineering types, the Wrangler YJ possesses the strongest, most rigid of all the Jeep chassis. That rigidity provides a significant advantage for off-road activities such as rock crawling. The stiff frame allows the suspension to do its job more effectively by flexing less. Of course, adding a well-designed roll cage will greatly increase the torsional rigidity of the chassis, and that creates the potential for a very serious rock crawler.
The original YJ looked similar to its predecessor: the CJ7. Refinements to the YJ allowed it to appeal to a broader audience with greatly improved creature comforts and on-highway drivability.
Since we are avid fans of rock crawling, we built a YJ in stages from simple to extreme. After all, world-class rock crawling trails are in our backyard with the John Bull, Dishpan Springs, and Gold Mountain trails minutes away. Johnson Valley OHV area is home of the Hammers trails and the iconic King of the Hammers desert and rock crawling race and is a mere 45 minute jaunt from us.
The Jeep Wrangler YJ is a very popular platform for building extreme rock crawlers.
The Jeep Wrangler YJ was one of the first vehicles equipped with true off-road capable tires, in this case the 30x9.5R15LT OWL Wrangler AT Tires. The standard YJ came with a soft top and half doors. (Jeep is a registered trademark of FCA US LLC)
The first stage for our YJ project will accommodate 33-inch tires. This will take a 4-inch lift. Next, we’ll use a spring-over conversion that mounts the springs over the axle but retains the stock springs. Bigger tires, up to 35 inches, can be used with this setup. Finally, an extreme rock crawler that is still California street-legal looms on the horizon. Coilover suspension, a stretched wheelbase, tires up to 40 inches, and an engine swap should allow us to rip up the rocks on trails such as Sledgehammer, Chocolate Thunder, Backdoor, and Jackhammer and then drive home in the street-legal beast when we’re exhausted.
Where aftermarket parts number in the thousands for the Wrangler JK, the YJ is not so blessed. But many parts are available and most will be showcased. The rocks are calling and we are ready to take them on!
Jeep Wrangler YJ History
Of all the Jeeps prior to the JK in 2007, the YJ stands out and is the most recognizable model. The most notable difference from the CJ7 visually is the grille and the rectangular headlights. When the YJ hit the showrooms in 1987, it was much criticized by the Jeep purists. Of course, the same thing has happened with the introduction of every new Jeep Wrangler model. The negative sentiment fades quickly as newcomers join the ranks of Jeep owners and the old timers soften because the new model actually offers many improvements. That happened with the YJ; except for the square headlights, many aficionados still malign the YJ because of the headlights.
The new Wrangler YJ was designed to improve comfort and highway handling to attract a broader daily driver market. The YJ went on sale on May 13, 1986, and production ceased at the end of 1995 with the 1995 production year. YJs were sold into the middle of 1996. Total YJ production topped 685,000 units.
In the last couple of years, the Wrangler YJ popularity has skyrocketed. And the resale prices are reflecting this trend. Prices have nearly doubled in a short time span. The popularity of the Wrangler JK offers the most likely explanation for this. In the last model year of the Wrangler JK, a Rubicon is more than $45,000 and the new JL Rubicon will top $50,000. High-mileage stock 2007 JK Sahara and X models fetch $10,000 and more. Modified, high-mileage JKs start in the $15,000 price range. Wrangler TJ Rubicon models with some modifications start at $10,000 and up. Similar YJs with some modifications start around $5,000. Because Jeepin’ has grown so fast in popularity, consumers have looked at other Jeep Wranglers as a starting point. The YJ offers many bargains even as the prices climb.
The Wrangler YJ, while similar in appearance to the CJ, was a totally new design. The YJ used leaf spring suspension, though the springs are wider. The YJ also featured track bars and sway bars for improved on-road handling. Overall, the Wrangler YJ is larger than the CJ7 and shares several components with the Cherokee XJ.
The Wrangler YJ used a 2.5-liter AMC inline 4-cylinder engine or the optional 4.2-liter inline 6-cylinder AMC 258 until 1990. In 1991, a fuel-injected 180-hp 4.0L inline-6 (the AMC 242) replaced the 112-hp 4.2L 6-cylinder engine. The NP207 transfer case was used in 1987 but was replaced by the NP231 the following year. This was a significant improvement for function and durability.
Shortly after the launch of the YJ, AMC was sold to Chrysler and the Jeep line became part of the Jeep/Eagle Division. This had little effect on production, as it continued at the Ontario, Canada, plant until it closed in 1992. Production was then moved to Toledo, Ohio, in the original plant were the Willys World War II vehicles were made.
The Standard S model of the Wrangler YJ was available with full doors and roll-up windows with the standard soft top. (Jeep is a registered trademark of FCA US LLC)
The Sahara option package included features such as body-color fender flares, steel wheels, interior door panels with pockets, front bumper–mounted fog lamps, and plastic ends on the front bumper. An AM/FM stereo with cassette player, rear speaker sound bar, unique cloth-and-vinyl high-back bucket seats, rear removable bench seat, and air-conditioning were all standard.
Suspension and Axles
The YJ uses Dana axles at both ends. The front axle is the semi-floating Dana 30 with a shaft disconnect system. It also has Hotchkis leaf springs, a stabilizer bar, and a track bar.
An interesting side note: the shaft disconnect system has made a comeback with the new Wrangler JL. The YJ used the disconnect system to eliminate the need for locking hubs, which are no longer needed with U-joint and CV joint axles. The new JL uses a similar system to reduce parasitic drag within the transfer case. This improves fuel economy by up to 1 mile per gallon and also reduces transfer case wear.
