Replacing the clutch in an AX-15 XJ means pulling the transfer case and transmission — plan the whole drivetrain drop, and do the pilot bearing, throwout bearing, and hydraulics while you're in there.
A slipping clutch shows up as engine RPM climbing without matching speed, worst in high gear under load or crawling uphill. A clutch that won't release — pedal to the floor and still grinding into first — points to a failing hydraulic circuit or a worn disc. Once the disc is down to the rivets you're risking the flywheel, so a slipping clutch is worth catching before it costs you a resurface or replacement.
The AX-15 lives behind the 4.0L with an NP231 or NP242 transfer case bolted to its tail. There's no getting the disc out without separating the transmission from the engine, which means the transfer case comes off first. Budget a full day; this is a labor job, not a parts job.
1989–1993 AX-15 XJs use an internal slave cylinder inside the bellhousing; 1994–1999 use an external slave that bolts to the outside. Confirm which you have before ordering — the throwout bearing and linkage differ. Replace the slave and bleed the hydraulics while the trans is out regardless; a $30 part now beats dropping the drivetrain twice.
> Flywheel bolts (crank-to-flywheel) torque to 105 ft-lb with thread locker. Only disturb them if you're pulling the flywheel to resurface or replace.
Steps
Disconnect the battery. Raise the Jeep on jack stands high enough to work under and get a transmission jack in.
Drain the transfer case and transmission. Mark and disconnect the front and rear driveshafts at the transfer case.
Disconnect the transfer case shift linkage, speedometer, and any wiring. Support the transfer case, unbolt it from the transmission, and remove it.
Support the transmission tail with a transmission jack. Remove the crossmember and lower the tail slightly for access to the upper bellhousing bolts.
Disconnect the clutch slave cylinder and hydraulic line, the backup light switch, and the shifter (from inside the cab, remove the shift boot and lift the shifter out).
Remove the starter and the bellhousing dust cover to expose the flywheel and pressure plate.
Remove the bellhousing-to-engine bolts. The two upper bolts are E12 external Torx and are the hardest to reach — an E12 socket on a long extension is the tool that saves the day.
Slide the transmission straight back off the input shaft — do not let it hang on the shaft. Lower it out on the jack.
Unbolt the pressure plate in a star pattern, a few threads at a time, to release spring pressure evenly. Remove the pressure plate and disc.
Pull the pilot bearing from the crankshaft with a slide-hammer puller or a hydraulic pilot bearing remover. Drive the new one in flush and square.
Inspect the flywheel for cracks, blue heat spots, or scoring. Resurface it if glazed; replace it if cracked. Clean the friction face with brake cleaner — no oil film.
Hang the new disc with the alignment tool through the hub into the pilot bearing. Note the "flywheel side" marking on the disc so it faces the right way.
Bolt the pressure plate to the flywheel in a star pattern. Torque to 40 ft-lb. Remove the alignment tool.
Grease the throwout bearing collar lightly and install the new throwout bearing and clutch fork.
Raise the transmission on the jack, align it square to the engine, and slide the input shaft into the disc splines and pilot bearing. Do not bolt it in by pulling on the bellhousing bolts — it should seat by hand first.
Torque the bellhousing-to-engine bolts to 28 ft-lb. Reinstall the starter and dust cover.
Reinstall the transfer case, crossmember, driveshafts, shifter, slave cylinder, and wiring. Refill the transmission and transfer case with 75W-90 GL-4.
Bleed the hydraulic clutch — gravity bleed or a helper on the pedal — until the pedal is firm and the clutch releases fully. Air in the line means partial engagement.
Reconnect the battery and test in a safe area before driving.
Why it works
Restores full clamp and clean engagement — no more slip on the climb
Doing the pilot bearing, throwout bearing, and slave cylinder in one drop avoids a second drivetrain pull
Stock-replacement kits hold the 4.0L's torque and cost far less than a shop clutch job
Trade-offs
Transfer case and transmission both have to come out — this is the labor cost, not the parts cost
The upper E12 Torx bellhousing bolts are awkward; the right socket is not optional
Requires a transmission jack and a clutch alignment tool; skipping alignment cracks input shafts
Hydraulics must be bled correctly or the new clutch won't release properly
Tools required
Floor jack and jack stands
Transmission jack
Torque wrench
Clutch alignment tool
E12 external Torx socket
Metric socket and wrench set
Pilot bearing puller (slide hammer or hydraulic type)
Parts
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Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.