generally happens when the container delivery mech-
anism is improperly calibrated. Always check the lu-
bricant level after filling to avoid an under fill
condition.
A correct lubricant level check can only be made
when the vehicle is level; use a drive-on hoist to en-
sure this. Also allow the lubricant to settle for a
minute or so before checking. These recommenda-
tions will ensure an accurate check and avoid an un-
der-or-overfill condition.
HARD SHIFTING
Hard shifting is usually caused by a low lubricant
level, improper or contaminated lubricants, compo-
nent damage, incorrect clutch adjustment, or by a
damaged clutch pressure plate or disc.
Substantial lubricant leaks can result in gear, shift
rail, synchro and bearing damage. If a leak goes un-
detected for an extended period, the first indications
of a problem are usually hard shifting and noise.
Incorrect or contaminated lubricants can also con-
tribute to hard shifting. The consequence of using
non-recommended lubricants is noise, excessive wear,
internal bind and hard shifting.
Improper clutch release is a frequent cause of hard
shifting. Incorrect adjustment or a worn, damagedpressure plate or disc can cause incorrect release. If
the clutch problem is advanced, gear clash during
shifts can result.
Worn or damaged synchro rings can cause gear clash
when shifting into any forward gear. In some new or re-
built transmissions, new synchro rings may tend to
stick slightly causing hard or noisy shifts. In most
cases, this condition will decline as the rings wear-in.
TRANSMISSION NOISE
Most manual transmissions make some noise during
normal operation. Rotating gears can generate a mild
whine that may only be audible at extreme speeds.
Severe, obviously audible transmission noise is
generally the result of a lubricant problem. Insuffi-
cient, improper, or contaminated lubricant can pro-
mote rapid wear of gears, synchros, shift rails, forks
and bearings. The overheating caused by a lubricant
problem, can also lead to gear breakage.
TRANSMISSION REMOVAL
(1) Shift transmission into first or third gear.
(2) Raise vehicle on a hoist.
(3) Disconnect necessary exhaust system components.
(4) Support transmission with adjustable jack stand.
(5) Disconnect rear cushion and mounting bracket
from transmission, or transfer case (Fig. 1).
Fig. 1 Rear Mount Components (YJ Shown)
JAX 15 MANUAL TRANSMISSION 21 - 35
(6) On XJ, remove rear crossmember. On YJ, re-
move skid plate (Fig. 1).
(7) Disconnect transmission shift linkage, speed-
ometer cable, transfer case vacuum lines and clutch
hydraulic lines.
(8) Lower transmission-transfer case assembly no
more than 7.6 cm (3 in.) for access to shift lever.
(9) Reach up and around transmission case and
unseat shift lever dust boot from transmission shift
tower (Fig. 2). Move boot upward on shift lever for
access to lever retainer.
(10) Disengage shift lever as follows:
(a) Reach up and around transmission case and
press shift lever retainer downward with your fin-
gers.
(b) Turn retainer counterclockwise to release it.
(c) Lift lever and retainer out of shift tower (Fig.
2).It is not necessary to remove shift lever
from floorpan boot. Simply leave lever in
place for later installation.(11) Mark front and rear propeller shafts for in-
stallation alignment (Fig. 2). Then remove both
shafts.
(12) Remove crankshaft position sensor (Fig. 4).
(13) Disconnect transmission and transfer case
vent hoses.
(14) Remove slave cylinder from clutch housing.
(15) Remove wire harnesses from clips/tie straps
on transmission and transfer case.
(16) Support transmission-transfer case assembly
with transmission jack. Secure assembly to jack with
safety chains.
(17) Reposition adjustable jack stand under engine.
Be sure to place wood block between jack and oil
pan.
(18) Remove clutch housing brace rod.
(19) Remove clutch housing-to-engine bolts and re-
move transmission-transfer case assembly.
(20) Remove bolts attaching transmission to trans-
fer case and separate components.
(21) Remove release bearing, fork and retainer
clip.
(22) Remove clutch housing from transmission.
TRANSMISSION INSTALLATION
(1) Install clutch housing on transmission. Tighten
housing bolts to 37 Nzm (27 ft-lbs) torque.
(2) Lubricate contact surfaces of release fork, lever
and pivot ball stud. Then install bearing, fork and
clip in clutch housing.
(3) Mount transmission on transmission jack. Se-
cure transmission with safety chains.
(4) Lightly lubricate pilot bearing and transmis-
sion input shaft splines with Mopar high tempera-
ture grease.
(5) Align transmission input shaft and clutch disc
splines and install transmission.
Fig. 2 Removing/Installing Shift Lever
Fig. 3 Marking Propeller Shaft And Axle Yoke
Fig. 4 Crankshaft Position Sensor Location
21 - 36 AX 15 MANUAL TRANSMISSIONJ
(6) Install and tighten clutch housing-to-engine
bolts to 38 Nzm (28 ft. lbs.) torque.Be sure housing
is properly seated on engine before tightening
bolts.
(7) Lower transmission no more than 7.6 cm (3 in.)
for access to the shift tower.
(8) Reach up and around the transmission and in-
sert shift lever in shift tower. Press lever retainer
downward and turn it clockwise to lock it in place.
Then install lever dust boot on shift tower.
(9) Install and connect crankshaft position sensor.
(10) Align and install transfer case on transmis-
sion. Tighten transfer case attaching nuts to 35 Nzm
(26 ft. lbs.) torque.
(11) Connect transfer case vacuum and vent hoses.
(12) Install and connect transfer case shift linkage.
Check and adjust linkage if necessary.
(13) Secure wire harnesses to clips/tie straps on
transmission and transfer case.
(14) Connect backup light switch wires.
(15) Install clutch slave cylinder.
(16) Connect vehicle speed sensor wires.
(17) On XJ, install rear crossmember and attach
cushion and bracket. Tighten crossmember-to-frame
bolts to 41 Nzm (30 ft. lbs.) torque. Tighten transmis-
sion-to-rear cushion and bracket bolts/nuts to 45 Nzm
(33 ft. lbs.) torque.
(18) On YJ, install rear cushion and bracket and
skid plate. Tighten attaching bolts/nuts to indicated
torque (Fig. 1).
(19) Align and install front/rear propeller shafts.
Tighten shaft U-joint clamp bolts to 19 Nzm (170 in.
lbs.) torque.
(20) On XJ, install skid plate if removed. Tighten
bolts to 42 Nzm (31 ft. lbs.) torque. Tighten stud nuts
to 17 Nzm (150 in. lbs.) torque.
(21) Top off transmission and transfer lubricant
levels.
(22) Remove supports and lower vehicle.
TRANSMISSION DISASSEMBLY AND OVERHAUL
ADAPTER HOUSING REMOVAL
(1) Remove release bearing, release lever and re-
lease fork from clutch housing. Then remove clutch
housing from transmission.
(2) Remove backup light switch. Then remove
drain plug (Fig. 1) and drain transmission lubricant
into pan.
(3) Remove shift tower bolts and remove tower
from adapter or extension housing (Fig. 2).
(4) Remove gasket from shift tower (Fig. 3).
Fig. 1 Drain Plug And Backup Light Switch Location
Fig. 2 Shift Tower Removal/Installation
Fig. 3 Shift Tower Gasket Removal/Installation
JAX 15 MANUAL TRANSMISSION 21 - 37
(5) Remove shift arm retainer bolt (Fig. 4).
(6) Loosen and remove restrictor pins (Fig. 5).
(7) Remove shift arm shaft plug (Fig. 6).(8) Remove shift arm shaft with large magnet (Fig. 7).
(9) Remove shift arm (Fig. 8).
(10) Remove plug for reverse shift head lock ball.
Plug is at right side of adapter housing near backup
light switch (Fig. 9).Fig. 4 Shift Arm Retainer Bolt Removal/Installation
Fig. 5 Removing/Installing Restrictor Pins
Fig. 6 Removing/Installing Shift Lever Shaft Plug
Fig. 7 Removing/Installing Shift Lever Shaft
Fig. 8 Shift Arm Removal/Installation
Fig. 9 Removing/Installing Lock Ball Plug
21 - 38 AX 15 MANUAL TRANSMISSIONJ
(3) Tap end of output shaft with mallet to unseat and
start rear bearing out of intermediate plate (Fig. 55).
(4) Remove output shaft by rocking it lightly until
rear bearing comes out of intermediate plate (Fig. 56).
(5) Remove cluster gear by pulling it straight out
of rear bearing (Fig. 57).(6) Remove cluster gear rear bearing from interme-
diate plate (Fig. 58).
(7) Remove input shaft from output shaft (Fig. 59).
(8) Remove output shaft pilot bearing from input
shaft (Fig. 60).
Fig. 55 Unseating Output Shaft Rear Bearing
Fig. 56 Input And Output Shaft Removal
Fig. 57 Cluster Gear Removal
Fig. 58 Removing Cluster Gear Rear Bearing
Fig. 59 Input Shaft Removal
Fig. 60 Input Shaft Pilot Bearing Removal
JAX 15 MANUAL TRANSMISSION 21 - 49
(28) Position new shift tower gasket on adapter
housing (Fig 127).
(29) Install shift tower (Fig. 128). Tighten tower
attaching bolts to 18 Nzm (13 ft. lbs.) torque.(30) Install new gasket on backup light switch and
install switch. Tighten switch to 37 Nzm (27 ft. lbs.)
torque.
(31) Install new washer on drain plug. Then install
and tighten plug to 37 Nzm (27 ft. lbs.) torque.
(32) If transmission will be filled with gear lubri-
cant before installation, place transmission in a level
position. Then fill with Mopar 75W-90, grade GL-5
gear lubricant.
(33) Install new washer on fill plug. Then install
and tighten plug to 37 Nzm (27 ft. lbs.) torque.
(34) Install clutch housing and hydraulic concen-
tric bearing.
(35) On models with extension housing, install new
seal in housing with suitable size installer tool (Fig.
129). Lubricate seal lips with petroleum jelly before
installation.
(36) On models with extension housing, install
speedometer driven gear, speedometer adapter and
speed sensor.
Fig. 127 Shift Tower Gasket Installation
Fig. 128 Shift Tower Installation
Fig. 129 Installing Extension Housing Seal
21 - 66 AX 15 MANUAL TRANSMISSIONJ
CONVERTER STALL TEST
Stall testing involves determining maximum engine
rpm obtainable at full throttle with the rear wheels
locked and the transmission in D range. This test
checks the holding ability of the converter overrun-
ning clutch and both of the transmission clutches.
When stall testing is completed, refer to the Stall
Speed Specifications chart and Stall Speed Diagnosis
guides.
WARNING: NEVER ALLOW ANYONE TO STAND IN
FRONT OF THE VEHICLE DURING A STALL TEST.
ALWAYS BLOCK THE FRONT WHEELS AND APPLY
THE SERVICE AND PARKING BRAKES DURING
THE TEST.
STALL TEST PROCEDURE
(1) Connect tachometer to engine.
(2) Check and adjust transmission fluid level.
(3) Start and run engine until transmission fluid
reaches normal operating temperature.
(4) Block front wheels.
(5) Fully apply service and parking brakes.
(6) Open throttle completely and record maximum
engine rpm registered on tachometer. It will take
from 3 to 10 seconds to reach maximum rpm. How-
ever, once maximum rpm has been achieved,do not
hold wide open throttle for more than 5 sec-
onds.
CAUTION: Stalling the converter causes a rapid in-
crease in fluid temperature. To avoid fluid overheat-
ing, hold wide open throttle for no more than 5
seconds after reaching peak rpm. In addition, if
more than one stall test is required, run the engine
at 1000 rpm with the transmission in Neutral for at
least 20 seconds to cool the fluid.
(7) Stall speeds should be in 1700-2150 rpm range.
CAUTION: If engine exceeds 2150 rpm, release ac-
celerator pedal immediately as transmission clutch
slippage is occurring.
(8) Shift transmission into Neutral. Run engine for
20-30 seconds at 1000 rpm to cool fluid. Then stop
engine, shift transmission into Park and release
brakes.
(9) Refer to Stall Test Diagnosis.
STALL TEST DIAGNOSIS
Stall Speed Too Low
Low stall speeds with a properly tuned engine in-
dicate a torque converter overrunning clutch prob-
lem. The condition should be confirmed by road
testing prior to converter replacement.The converter overrunning clutch is slipping when
stall speeds are 250 to 350 rpm below specified min-
imum.
A converter overrunning clutch failure will result
in sluggish acceleration in all speed ranges. It will
also require greater than normal throttle opening to
maintain cruising speeds.
Stall Speed Too High
If stall speed exceeds 2150 rpm, transmission
clutch slippage is occurring.
Stall Speed Normal But Acceleration Is Sluggish
If stall speeds are within specified range but abnor-
mal throttle opening is required for acceleration, or
to maintain cruise speeds, the converter overrunning
clutch is seized. The torque converter will have to be
replaced.
Converter Noise During Test
A whining noise caused by fluid flow is normal dur-
ing a stall test. However, loud metallic noises indi-
cate a damaged converter. To confirm that noise is
originating from the converter, operate the vehicle at
light throttle in Drive and Neutral on a hoist and lis-
ten for noise from the converter housing.
AIR PRESSURE TEST
Air pressure testing can be used to check clutch
and band operation with the transmission either in
the vehicle, or on the work bench as a final check af-
ter overhaul.
Air pressure testing requires that the oil pan and
valve body be removed from the transmission.
The servo and clutch apply passages are shown in
Figure 8.
Air Test Procedure
(1) Place one or two fingers on the clutch housing
and apply air pressure through front clutch apply
passage (Fig. 8). Piston movement can be felt and a
soft thud heard as the clutch applies.
(2) Place one or two fingers on the clutch housing
and apply air pressure through rear clutch apply
passage (Fig. 8). Piston movement can be felt and a
soft thud heard as the clutch applies.
(3) Apply air pressure to the front servo apply pas-
sage. The servo rod should extend and cause the
band to tighten around the drum. Spring tension
should release the servo when air pressure is re-
moved.
(4) Apply air pressure to the rear servo apply pas-
sage. The servo rod should extend and cause the
band to tighten around the drum. Spring tension
should release the servo when air pressure is re-
moved.
21 - 74 30RH/32RH TRANSMISSION DIAGNOSISJ
on transmission. Tighten pan bolts to 17 Nzm (150 in.
lbs.) torque.
(7) Lower vehicle.
(8) Refill transmission with Mopar ATF Plus.
VALVE BODY REMOVAL
(1) Raise vehicle.
(2) Remove oil pan and drain fluid.
(3) Disconnect gearshift and throttle linkage at
transmission levers.
(4) Loosen clamp bolts and remove throttle and
manual valve levers from manual valve shaft.
(5) Disconnect park/neutral position switch wires
and remove switch and switch seal.
(6) Remove valve body oil filter.
(7) Remove valve body attaching screws. Lower
valve body slightly and remove accumulator piston
and spring (Fig. 11). Rotate valve body down and
away from case. Pull it forward to disengage park
rod and remove valve body.
(8) Position valve body on bench or on repair stand
for disassembly, cleaning and inspection (Fig. 12).
VALVE BODY SERVICE
The valve body can be disassembled for cleaning
and inspection of the individual components. Valve
body service procedures are detailed in the overhaul
section.
The only serviceable valve body components are:
²park lock rod and E-clip
²switch valve and spring
²pressure adjusting screw bracket
²throttle valve lever
²manual lever
²manual lever shaft seal, washer, E-clip and detent
ball
²fluid filter
²converter clutch solenoid
The remaining valve body components are serviced
only as part of a complete valve body assembly.
VALVE BODY INSTALLATION
(1) Place valve body manual lever in low (1 posi-
tion) so park lock rod can be installed in sprag.
(2) Position park sprag with screwdriver to ease
lock rod installation and engagement.
(3) Install new seals on accumulator piston if nec-
essary and install piston in case. A small amount of
petroleum jelly can be used to hold piston in place.
(4) Lubricate shaft of manual lever and lip of shaft
seal with petroleum jelly.
(5) Raise valve body and align park rod with case
opening and park sprag. Then push rod end through
opening and past sprag. Rotate propeller shaft if nec-
essary.
(6) Position accumulator spring on transfer plate.
Fig. 10 Oil Filter Screw Locations
Fig. 11 Accumulator Piston And Spring
Fig. 12 Valve Body Assembly
21 - 104 30RH/32RH IN-VEHICLE SERVICEJ