1987-1995 Jeep Wrangler (YJ): change comes to the CJ
The Jeep CJ (Civilian Jeep), an icon based on the American Bantam military vehicles, ceased production in 1986. Around 1.6 million CJs built by Willys, Kaiser, and AMC over the course of four decades, starting with the 1946 Jeep CJ-2A. The first hardtop came in 1972. Each new CJ model was larger and more popular than the one before it, but none were hot sellers, with U.S. sales between 10,000 and 60,000 per year.
In late 1983, twelve prototypes had been built for testing; they had a new chassis and powertrain. By spring 1984, nine prototypes with final sheet metal were tested for durability. Packaging bucks were built to check design clearances, comfort, the tops, and instrumentation. About 600,000 miles total were acquired through all the testing.
|... at axles (min)||6.9||6.9||7.5 (rear)|
|Weight (I-4)||2,600*||2,700*||2,910-2,943 lb|
|* Depending on source, CJ5 is 2,200-2,660 and CJ-7 is 2,600-2710.|
Code-named YJ, the first major re-engineering of the old CJ line was named Wrangler in the United States, YJ in Canada. It was first shown in February 1986 at the Chicago Auto Show, and landed in showrooms on May 13, 1986.
Functionally, the biggest difference was the new suspension, altered to avoid flip-overs, which had become increasingly common as CJs became popular for recreation. The YJ, like CJ, was a live-axle design with a Hotchkiss (parallel leaf spring) suspension. In short, the car used longitudinal, semi-elliptical leaf springs in the front and rear, with a front stabilizer bar and front and rear track bars.
To increase stability, the springs were widened and moved further apart, and a “track bar,” or Panhard rod, was added (along with numerous other changes). The setup worked well in preventing rollovers, though Jeep engineer Evan Boberg wrote, “the ride quality was very poor ... [and] stiffer springs were required to meet durability requirements, making the ride even worse.”
This suspension was unique to the YJ; in 1997, Jeep Wrangler debuted with an variant of the Jeep Cherokee’s link/coil system. In front, it used an inverted pinion axle with a vacuum-actuated disconnect. Shift linkages were mounted on the powertrain.
In a move familiar to those who followed Cherokee, Grand Cherokee, and Liberty, Jeep started production of the YJ in Canada at its Brampton plant, while winding down CJ production in Toledo. It would continue to be made in Canada for many years.
The front half of the Wrangler had a more contemporary look than the CJ, and with fashionable square headlights (de rigeur for cars starting in the late 1970s) and parking lamps. It had a raised hood center panel and a seven-slot, horizontally vee’d grille. These changes were largely made to distinguish it from CJ, according to Mr. Boberg.
Not surprisingly, given its traditionally low production volumes, Wrangler shared many components with the Jeep Cherokee, including its brakes, axles, steering system, wheels, tires, manual transmission, and hydraulic clutch. They also shared the New Process Gear NP207 transfer case, which gave Wrangler the same “shift-on-the-fly” capabilities as Cherokee (new-for-’84).
A tubular side-rail design chassis added strength and durability, eliminating the stress risers from welding stamped-steel channels. A uniform section modulus throughout the rail increased torsional strength, durability, and flexibility. This frame was, overall, far stronger than that of the CJ, and the body as a whole was less prone to rust. Still, it could eventually rot and crack in the rear. The frame would be substantially strengthened in 1997 models, but the basic design continued.
The Wrangler also had a one-step, swing-away tailgate with spare tire mount. The exterior body panels were made of galvanized steel, making them corrosion resistant; the hood, grille guard, fenders, and windshield were also cathodic electro-coated. The standard splash shield was about 10 inches back from the front fenders; an optional full splash shield from the front to rear fenders had a built-in body side step.
Under the hood at launch was a AMC fuel-injected, 2.5-liter inline four cylinder; a 4.2-liter, carbureted six cylinder was optional. A five-speed manual was standard, but optional with the six-cylinder engine only was a three-speed automatic. Oddly, the four-cylinder had a higher horsepower rating, but the six was a much more satisfying motor due to its stronger torque. This would be addressed in 1991, when the fuel-injected 4.0 liter I-6 replaced the 4.2; the design of the engines was similar, but the 4.0 dispensed with the problematic carburetors and provided much more power.
Chart note: gas mileage is according to pre-1980 standards and has not been adjusted.
|1987 specifications||4.0 I-6 (1991+)|
|Block and head||Cast Iron||Cast Iron||Cast Iron|
|Bore and Stroke||3.88" x 3.19"||3.75" x 3.9"||3.88 x 3.41|
|Displacement||150 CID; 2.5 liters||258 CID; 4.2 liters||242 cid|
|Brake Horsepower||117 @ 5,000 RPM*||112 @ 3,000 RPM||180 @ 4,750|
|Maximum Torque||135 lb-ft. @ 3,500 RPM||210 lb-ft. @ 3,000 RPM||220 @ 4,000|
|EPA mpg, 1987||18/20||17/21 (manual)|
|EPA mpg, 1994||18/20||not available||16/20 (manual)|
|Axles||Front: Dana 30; Rear: Dana 35C|
|Manual Transmission||5-speed; Peugeot and Aisin||Aisin|
In 1991, the four-cylinder was upgraded to 123 hp and 139 lb-ft of torque, with the same compression ratio; peak horsepower came in at 5,250 rpm but peak torque was dropped to 3,250 rpm. The part-time transfer case was a New Venture Gear NV231, with a 2.72:1 low range ratio; a three-speed automatic was optional, a five-speed manual was standard.
The Wrangler had comfort amenities the CJs didn’t, in AMC’s ongoing attempt to make Jeep into a true mainstream brand — an effort that followed Kaiser’s and Willys’ own attempts to make Jeep a bigger seller among the general public. Thus, standard equipment included power brakes, high-back front bucket seats, fold-and-tumble rear seat, P215/75R15 tires, mini front carpet pad, front stabilizer bar, tinted windshield, padded roll bar (with side rails going to windshield frame), and wiper/washer controls on the steering column. Wrangler also had a padded instrument panel and carpet trim on the lower portions of the doors. The high beam switch and cruise control stalk were also moved to the steering column.
Inside, a modern instrument panel was adopted, albeit with tiny gauges, repositioned for convenience.
An AM/FM radio with dual speakers was available in all trims; optional were an AM/FM electronically tuned stereo and an AM/FM ETR cassette stereo with Dolby. Standard color choices were Olympic white, beige, Colorado red, black, and sun yellow. Metallic color choices were mist silver, garnet, medium and dark blue, autumn brown, and mocha brown. Soft tops were available in white, black, or honey.
Wrangler was available in base, Sports Decor, and Laredo trims; base and Sports had steel lower half doors and a removable soft top (starting a series of “reduced air, water, and noise intrusions” claims that would last for decades), Laredo only had a hard top with flush side glass, a full-glass lift gate, and air extractors to improve ventilation; an electric rear-window defroster was optional.
|Cargo Volume||5.31 c.f.|
|Weight dist. (I-4)||50/50|
|Drag coefficient||0.63 hardtop|
|Frontal area||26.5 sq.ft.|
Starting in 1988, Chrysler phased out components made by GM and Ford on all the Jeeps; generally, this was a good thing for Jeep. More to the point, Wrangler gained a new high-end package, the Sahara, which included a khaki soft top, steel spoke wheels, dual mirrors, fog lamps, and various cosmetic additions (CJ had been dressed up in similar fashion in the past). The company build 46,294 Wranglers for 1988, according to the Standard Catalog of Chrysler, a number dwarfed by nearly 160,000 Cherokees; they even built more Comanche pickups than Wranglers. The last pre-Cherokee model, Grand Wagoneer, had sales of just 16,228.
For 1989, 56,008 Wranglers were sold. In 1990, Jeep improved lateral support on the front seats, changed the lock system on soft top models with half-steel doors, added a rear wiper/washer to the hard top, made the 20-gallon tank standard on Sahara and Laredo, added side-marker turn signal flashers, made FM stereos standard on most models, and used P225 off-road tires in the off-road option group; sales dropped back to 47,436.
1991 was a big year for Wrangler, with a brand new 4.0 liter high output “PowerTech” six cylinder engine — based on the 2.5 four cylinder, but with multiple-port fuel injection and other improvements. In the same year, the 2.5 liter four-cylinder was upgraded to multiple port injection, boosting its power as well — but it was six cylinder buyers who really felt the love, with better gas mileage and nearly 70 horsepower more. Wrangler sales still fell again, to 45,576.
In 1991, the first Jeep Renegade, “the ultimate Wrangler,” left the production lines, with a 180 horsepower / 220 lb-ft 4.0 liter engine; it included standard reclining front bucket seats, larger gas tank, and aluminum wheels, with four paint colors and two interior colors.
For 1993, Wrangler gained a stainless-steel exhaust system, tamper-resistant odometer, revised soft top, and optional four-wheel antilock brakes.
For 1994, Wrangler was updated to have a center high-mounted brake light, R134a refrigerant, a sound bar on the “S” model, and an “add-a-trunk” option. Buyers also got an optional “easy operating” soft top with full doors, a three-speed available with the four-cylinder, and a higher performance torque converter with the 4.0.
Jeep Wrangler YJ in retrospect
The cars had their flaws. These could include, over the years, exhaust manifold cracking, driveshaft vibration, carburetor failure, leaking differentials, clutch cylinder leaks, and leaking rear main seals (some of these were common on numerous vehicles.) Some advise getting a 1991 or newer model (which had the fuel injected 4.0 liter I-6, replacing the 4.2) to avoid the carburetors on the 4.2 engine; and the Peugeot transmissions have been criticized by owners.
Overall, the YJ was a major step for the “civilian Jeep,” answering changing demographics (from farmers to off-road enthusiasts) and addressing an old safety problem that was now increasingly important, without giving up the essence of the CJ. The square headlights would come in for their share of criticism, but were seen as needed at a time when every car had switched from the old-fashioned round units.
The YJ was still not all it needed to be to reach a large audience, though. As Evan Boberg wrote, Chrysler did some research to find what they needed to do to boost sales, when working on the next generation. He wrote:
The reason most people bought a Wrangler was just because they had always wanted a Jeep. ... rarely did anyone buy a second one. The biggest complaints about the Wrangler were the poor ride and the noise from the soft top.
In the next generation, the ride and noise would be addressed, with varying degrees of success — along with another major customer complaint: the square headlights were permanently ejected.
|Wrangler specs, parts, repairs||Wrangler ancestors, models, and reviews|
The 2018 Jeep Wrangler JL: