Jeep Wrangler YJ
Built from 1987 to 1995, the Wrangler YJ was AMC's/Chrysler's rendition of the short-wheel-base model Jeep that AMC was currently producing up until this time (known as the CJ-7). The Wrangler YJ's first distinction was its square headlights — something unheard of in the Jeep's then 46-year history. It also featured a longer wheelbase, lower ground clearance, wider leaf springs, and traction and panhard bars to make the vehicle extremely stable for the growing consumer market that would be spending more time using their Jeeps as daily driver vehicles and less time as recreational off-road vehicles. 685,071 Wranglers were produced from 1987 to 1995.
Axles
Factory Dana 30 front & Dana 35 rear, gear ratios, and Super 35 notes.
Engines
AMC 2.5L, 4.2L, and 4.0L power plants used from 1987–95.
Transmissions
AX-5, BA-10, AX-15 manuals and the AW30-40 automatic.
Transfer Cases
NP207 (1987) and NP231 (1988–95) specs and identification.
Gear Ratio Guide
Estimated highway RPM chart for tire size vs. ring & pinion ratio.
Gas Tank Conversion
How to unlock the full 20-gallon capacity on 1991–95 tanks.
Rubicon Express SYE
Step-by-step NP231 slip yoke eliminator install with photos.
Factory at a glance
Engine: AMC 150 (2.5L), AMC 258 (4.2L), 242 (4.0L).
Transmission: Peugeot BA 10/5, Aisin Warner AX-5, Aisin Warner AX-15, Aisin-Warner AW30-40.
Transfer Case: New Process 207, New Process 231
Axles: Dana 30, Dana 35
Ring and Pinion Ratios: 3.07 / 3.08 (6-cyl), 4.10 / 4.11 (4-cyl)