In mid 1986, after 42 years of Jeep CJ tradition, the Wrangler YJ was introduced for the '87 model year. It featured a number of new styling, suspension, and design changes over its predecessor. The most dramatic engineering change on the YJ was the redesigned front end, including a new hood, fenders, grille, larger windshield, and headlights-square headlights. The new Wrangler looked considerably different from the tried and true CJ. Jeepers either loved it or hated it. The biggest gripe was the square headlights, which left die-hard Jeep enthusiasts scratching their heads wondering what happened to Jeep tradition.
From the cowl back, the YJ is almost the same as the last model of CJ, except for a sporty new dashboard and gauges. AMC's big push for a better-handling more comfortable Jeep included redesigning the suspension with wider leaf springs, a lower ride height, a slightly longer wheelbase, sway bars, and track bars for better stability and on-road handling.
Regardless of its styling differences, the YJ was like any other Jeep, a utilitarian vehicle used by folks such as us for off-road adventure. The early YJs were powered by a 2.5L inline-four AMC 150 cid or optional 4.2L inline-six AMC 258 cid. Introduced with the '91 model was the more efficient and powerful fuel-injected 4.0L 242 cid. The 4.0L had approximately 70 more horsepower than the 4.2L and pushed the Wrangler to more capable performance levels.
The YJ in stock form is a great vehicle for wheeling mild trails and a good platform for building an even more capable Jeep. Hardcore four-wheeling will require extensive modifications to the axles, suspension, engine, transmission, and transfer case.
Many people occasionally find good deals on YJs. However, on the Internet the average price of one in decent shape is over $3,000, so they are not as cheap as we budget-minded shoppers would like.
YJs are still popular because they are far more affordable than a TJ or JK Wrangler and fun to build. In the South we find lots of YJs built with Rockwell axles and big blocks, and in places like Colorado they are mildly built for harsh winter and high-country trails. We still get a thrill out of driving the ol' four-banger stocker YJ to the store and back.
Building a YJ
If you're looking to build a YJ, there are a number of options and directions you can take, both high- and low-dollar. We would look for a '91-'95 with the 4.0L engine. This is a good place to start since engine and transfer case components are more readily available.
YJs aren't as cheap as we would like them to be, but the occasional great deal can be had on a well-abused one. We love leaf springs and the 4.0L engine. If we were going to build a YJ it wouldn't be that economical of a project, but we are sure we could build it without breaking the bank and still have a capable trail crawler and grocery getter when we were finished.
|OUR YJ BUILD PLAN
|•'91-'95 YJ 4.0L with automatic transmission, NP231 transfer case
|•Detroit Locker rear axle
|•Powertrax No-Slip front axle
|•Skyjacker 4-inch lift with front and rear leaf springs & shocks
|•Olympic 4x4 front A/T Rock Slider Bumper
|•Rugged Ridge 8,500-lb winch
|•Dick Cepek Mud Country 33-inch tires on factory wheels
The I-4 motor is basically the same as the 258ci engine minus two cylinders. The initial horsepower output of the engine was around 112 and went up slightly with later models, but parasitic loss through the drivetrain brings the horsepower rating of this engine down even lower. If the plan is to modify a YJ with larger tires and axles, then we recommend finding one fitted with an I-6. When searching for a YJ we recommend finding one that has the High Output 4.0L 242 cid engine, which was optional in '91-'95 YJs. This engine not only produces far more horsepower that the 2.5L and 4.2L ones, but many components and intakes are available to boost the engine's performance.
Unfortunately the YJ didn't come with too many axles options. In fact, the Jeep only came with a Dana 30 front and a Dana 35c rear axle. All the front Dana 30 front axles came with the problematic vacuum disconnect. Fortunately, there are several aftermarket parts available to beef up both axles. A few companies even offer stronger alloy axleshafts with higher spline counts. The vacuum disconnect problem can be fixed with a one-piece shaft from a TJ or a 4x4 Posi-Lok.
The YJ didn't come with a lot of great transmission options, but with proper care they it last in most on- and off-highway driving conditions. The light-duty AX-5 was the standard five-speed manual transmission behind the I-4, with the TorqueFlite 904 available in '94-'95 models. The Peugeot BA-10 five-speed manual transmission sat behind the 4.2L and isn't compatible with hardcore four-wheeling. The Chrysler three-speed automatic (TorqueFlite 999) and AX-15 manual sat behind the H.O. 4.0L.
The transfer case in the '87-'91 YJ was the New Process 207. The NP207 was chain-driven and worked well in most conditions and terrain, and it is capable of withstanding most tough wheeling situations. The NP231 transfer case was placed in the '91 YJ and featured 2H, 4H, N, and 4L. It's a great transfer because it's designed for rugged use and a plethora of aftermarket parts is available for upgrades, including a heavy-duty rebuild kit.
We don't really like the dash of the YJ and the way the instruments are placed inside. The entire dash has to come apart to replace or repair a broken gauge. We like our Jeep dashes steel with easy-to-remove gauges, plus a steel dash can be easily modified for adding accessories.