CAUTION: Verify that the oil squirt holes in the rods
face the camshaft and that the arrows on the pis-
tons face the front of the engine.
(7) Install the oil pan and gaskets as outlined in
the installation procedure.
(8) Lower the vehicle.
(9) Install the engine cylinder head, push rods,
rocker arms, bridges, pivots and engine cylinder head
cover.
(10) Fill the crankcase with engine oil.
CRANKSHAFT MAIN BEARINGS
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the spark plugs.
(3) Raise the vehicle.
(4) Remove the oil pan and oil pump.
(5) Remove only one main bearing cap and lower
insert at a time (Fig. 1).
(6) Remove the lower insert from the bearing cap.
(7) Remove the upper insert by LOOSENING (DO
NOT REMOVE) all of the other bearing caps. Now
insert a small cotter pin tool in the crankshaft jour-
nal oil hole. Bend the cotter pin as illustrated to fab-
ricate the tool (Fig. 2). With the cotter pin tool in
place, rotate the crankshaft so that the upper bear-
ing insert will rotate in the direction of its locking
tab. Because there is no hole in the No.3 main jour-
nal, use a tongue depressor or similar soft-faced tool
to remove the bearing insert (Fig. 2). After movingthe insert approximately 25 mm (1 inch), it can be
removed by applying pressure under the tab.
(8) Using the same procedure described above, re-
move the remaining bearing inserts one at a time for
inspection.
INSPECTION
Wipe the inserts clean and inspect for abnormal
wear patterns and for metal or other foreign material
imbedded in the lining. Normal main bearing insert
wear patterns are illustrated (Fig. 3).
If any of the crankshaft journals are scored,
remove the engine for crankshaft repair.
Inspect the back of the inserts for fractures, scrap-
ings or irregular wear patterns.
Inspect the upper insert locking tabs for damage.
Replace all damaged or worn bearing inserts.
Fig. 1 Removing Main Bearing Caps and Lower
Inserts
Fig. 2 Removing Upper Inserts
Fig. 3 Main Bearing Wear Patterns
J2.5L ENGINE 9 - 45
VALVE COMPONENT REPLACEÐCYLINDER HEAD
NOT REMOVED
ROCKER ARMS AND PUSH RODS
This procedure can be done with the engine in or
out of the vehicle.
REMOVAL
(1) Remove the engine cylinder head cover.
(2) Remove the capscrews at each bridge and pivot
assembly (Fig. 2). Alternately loosen the capscrews
one turn at a time to avoid damaging the bridges.
(3) Check for rocker arm bridges which are causing
misalignment of the rocker arm to valve tip area.
(4) Remove the bridges, pivots and corresponding
pairs of rocker arms (Fig. 2). Place them on a bench
in the same order as removed.
(5) Remove the push rods and place them on a
bench in the same order as removed.
CLEANING
Clean all the components with cleaning solvent.
Use compressed air to blow out the oil passages in
the rocker arms and push rods.
INSPECTION
Inspect the pivot surface area of each rocker arm.
Replace any that are scuffed, pitted, cracked or ex-
cessively worn.
Inspect the valve stem tip contact surface of each
rocker arm and replace any rocker arm that is deeply
pitted.
Inspect each push rod end for excessive wear and
replace as required. If any push rod is excessivelyworn because of lack of oil, replace it and inspect the
corresponding hydraulic tappet for excessive wear.
Inspect the push rods for straightness by rolling
them on a flat surface or by shining a light between
the push rod and the flat surface.
A wear pattern along the length of the push rod is
not normal. Inspect the engine cylinder head for ob-
struction if this condition exists.
INSTALLATION
(1) Lubricate the ball ends of the push rods with
Mopar Engine Oil Supplement, or equivalent and in-
stall push rods in their original locations. Ensure
that the bottom end of each push rod is centered in
the tappet plunger cap seat.
(2) Using Mopar Engine Oil Supplement, or equiv-
alent, lubricate the area of the rocker arm that the
pivot contacts. Install rocker arms, pivots and bridge
above each cylinder in their originally position.
(3) Loosely install the capscrews through each
bridge.
(4) At each bridge, tighten the capscrews alter-
nately, one turn at a time, to avoid damaging the
bridge. Tighten the capscrews to 28 Nzm (21 ft. lbs.)
torque.
(5) Install the engine cylinder head cover.
VALVE STEM SEAL AND SPRING REPLACEMENT
This procedure can be done with the engine cylin-
der head installed on the block.
REMOVAL
Each valve spring is held in place by a retainer and
a set of conical valve locks. The locks can be removed
only by compressing the valve spring.
(1) Remove the engine cylinder head cover.
(2) Remove capscrews, bridge and pivot assemblies
and rocker arms for access to each valve spring to be
removed.
(3) Remove push rods. Retain the push rods,
bridges, pivots and rocker arms in the same order
and position as removed.
(4) Inspect the springs and retainer for cracks and
possible signs of weakening.
(5) Remove the spark plug(s) adjacent to the cylin-
der(s) below the valve springs to be removed.
(6) Connect an air hose to the adapter and apply
air pressure slowly. Maintain at least 621 kPa (90
psi) of air pressure in the cylinder to hold the valves
against their seats. For vehicles equipped with an air
conditioner, use a flexible air adaptor when servicing
the No.1 cylinder.
(7) Tap the retainer or tip with a rawhide hammer
to loosen the lock from the retainer. Use Valve Spring
Compressor Tool MD-998772A to compress the spring
and remove the locks (Fig. 3).
(8) Remove valve spring and retainer (Fig. 3).
Fig. 2 Rocker Arm Assembly
J4.0L ENGINE 9 - 65
(8) Lower the vehicle.
(9) Install the engine cylinder head, push rods,
rocker arms, bridges, pivots and engine cylinder head
cover.
(10) Fill the crankcase with engine oil.
CRANKSHAFT MAIN BEARINGS
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the spark plugs.
(3) Raise the vehicle.
(4) Remove the oil pan and oil pump.
(5) Remove only one main bearing cap and lower
insert at a time (Fig. 1).
(6) Remove the lower insert from the bearing cap.
(7) Remove the upper insert by LOOSENING (DO
NOT REMOVE) all of the other bearing caps. Now
insert a small cotter pin tool in the crankshaft jour-
nal oil hole. Bend the cotter pin as illustrated to fab-
ricate the tool (Fig. 2). With the cotter pin tool in
place, rotate the crankshaft so that the upper bear-
ing insert will rotate in the direction of its locking
tab. Because there is no hole in the No.3 main jour-
nal, use a tongue depressor or similar soft-faced tool
to remove the bearing insert (Fig. 2). After moving
the insert approximately 25 mm (1 inch), it can be
removed by applying pressure under the tab.
(8) Using the same procedure described above, re-
move the remaining bearing inserts one at a time for
inspection.
INSPECTION
Wipe the inserts clean and inspect for abnormal
wear patterns and for metal or other foreign material
imbedded in the lining. Normal main bearing insert
wear patterns are illustrated (Fig. 3).
If any of the crankshaft journals are scored,
remove the engine for crankshaft repair.
Inspect the back of the inserts for fractures, scrap-
ings or irregular wear patterns.
Inspect the upper insert locking tabs for damage.
Replace all damaged or worn bearing inserts.
FITTING (CRANKSHAFT INSTALLED)
The main bearing caps, numbered (front to rear)
from 1 through 7 have an arrow to indicate the for-
Fig. 1 Removing Main Bearing Caps and Lower
Inserts
Fig. 2 Removing Upper Inserts
Fig. 3 Main Bearing Wear Patterns
J4.0L ENGINE 9 - 87
TRANSMISSION IDENTIFICATION
The AX 4/5 identification code is on the bottom sur-
face of the transmission case near the fill plug (Fig. 2).
The first number is year of manufacture. The second
and third numbers indicate month of manufacture. The
next series of numbers is the transmission serial num-
ber.
GEAR RATIOS
Gear ratios for the AX 4 and AX 5 are as follows:
²First gear: 3.93:1
²Second gear: 2.33:1
²Third gear: 1.45:1
²Fourth gear: 1.00:1
²Fifth gear (AX 5): 0.85:1
²Reverse gear: 4.74:1
SHIFT PATTERN
The AX 4/5 first through fourth gear shift pattern
is in a conventional H configuration. On the AX 5,
fifth gear is up and to the right and reverse gear is
down and to the right (Fig. 3).
RECOMMENDED LUBRICANT
Recommended lubricant for AX 4/5 transmissions is
Mopar 75W-90, API Grade GL-5 gear lubricant, or
equivalent.
Correct lubricant level is from the bottom edge, to
no more than 6 mm (1/4 in.) below the bottom edge of
the fill plug hole.
The fill plug is at the passenger side of the adapter
housing Fig. 4). The drain plug is at the bottom of
the case.
Approximate dry fill lubricant capacity is 3.3 liters
(3.5 qts.).
SERVICE DIAGNOSIS
LOW LUBRICANT LEVEL
A low transmission lubricant level is generally the
result of a leak, inadequate lubricant fill, or an incor-
rect lubricant level check.
Leaks can occur at the mating surfaces of the gear
case, intermediate plate and adaptor or extension
housing, or from the front/rear seals. A suspected
leak could also be the result of an overfill condition.
Leaks at the rear of the extension or adapter hous-
ing will be from the housing oil seals. Leaks at com-
ponent mating surfaces will probably be the result of
inadequate sealer, gaps in the sealer, incorrect bolt
tightening, or use of a non-recommended sealer.
A leak at the front of the transmission will be from
either the front bearing retainer or retainer seal. Lu-
bricant may be seen dripping from the clutch housing
after extended operation. If the leak is severe, it may
also contaminate the clutch disc causing slip, grab
and chatter.
Transmissions filled from air or electrically powered
lubricant containers can be underfilled. This generally
Fig. 2 Transmission Identification
Fig. 3 AX 4/5 Shift Pattern
Fig. 4 Fill Plug Location
21 - 2 AX 4/5 MANUAL TRANSMISSIONJ
AX 15 MANUAL TRANSMISSION
INDEX
page page
General Information....................... 33
Service Diagnosis......................... 34
Transmission Assembly and Adjustment......... 52
Transmission Disassembly and Overhaul........ 37
Transmission Gear Ratios................... 34
Transmission Identification.................. 33Transmission Installation.................... 36
Transmission Lubricant..................... 34
Transmission Removal..................... 35
Transmission Shift Pattern................... 34
Transmission Switch and Plug Locations........ 34
GENERAL INFORMATION
The AX 15 is a 5-speed, synchromesh, manual
transmission. Fifth gear is an overdrive range with a
ratio of 0.79:1. The shift mechanism is integral and
mounted in the shift tower portion of the adapter
housing (Fig. 1).
An adapter housing is used to attach the transmis-
sion to the transfer case on 4-wheel drive models. A
standard extension housing is used on 2-wheel drive
models.
The AX 15 is used in XJ and YJ models with a 4.0L
engine. The AX 15 is used for two and four-wheel
drive applications.
TRANSMISSION IDENTIFICATION
The AX 15 identification code numbers are on the
bottom surface of the transmission gear case (Fig. 2).
Fig. 1 AX 15 Manual Transmission
Fig. 2 Identification Code Number Location
JAX 15 MANUAL TRANSMISSION 21 - 33
The first number is year of manufacture. The sec-
ond and third numbers indicate month of manufac-
ture. The next series of numbers is the transmission
serial number.
TRANSMISSION SHIFT PATTERN
The AX 15 shift pattern is shown in Figure 3. First
and second and third and fourth gear ranges are in
line for improved shifting. Fifth and reverse gear
ranges are also in line at the extreme right of the
pattern (Fig. 3).
The AX 15 is equipped with a reverse lockout
mechanism. The shift lever must be moved through
the Neutral detent before making a shift to reverse.
TRANSMISSION LUBRICANT
Recommended lubricant for AX 15 transmissions is
Mopar 75W-90, API Grade GL-5 gear lubricant, or
equivalent.
Correct lubricant level is from the bottom edge, to
no more than 6 mm (1/4 in.) below the bottom edge of
the fill plug hole.
Approximate dry fill lubricant capacity is:
²3.10 liters (3.27 qts.) in 4-wheel drive models
²3.15 liters (3.32 qts.) in 2-wheel drive models
TRANSMISSION SWITCH AND PLUG LOCATIONS
The fill plug is at the driver side of the gear case
(Fig. 4).
The drain plug and backup light switch are on the
passenger side of the gear case (Fig. 5).
TRANSMISSION GEAR RATIOS
AX 15 gear ratios are:
First gear - 3.83:1
Second gear - 2.33:1
Third gear - 1.44:1
Fourth gear - 1.00:1
Fifth gear - 0.79:1
Reverse - 4.22:1
SERVICE DIAGNOSIS
LOW LUBRICANT LEVEL
A low transmission lubricant level is generally the
result of a leak, inadequate lubricant fill, or an incor-
rect lubricant level check.
Leaks can occur at the mating surfaces of the gear
case, intermediate plate and adapter or extension
housing, or from the front/rear seals. A suspected
leak could also be the result of an overfill condition.
Leaks at the rear of the extension or adapter hous-
ing will be from the housing oil seals. Leaks at com-
ponent mating surfaces will usually be the result of
inadequate sealer, gaps in the sealer, incorrect bolt
tightening, or use of a non-recommended sealer.
A leak at the front of the transmission will be from
either the front bearing retainer or retainer seal. Lu-
bricant may be seen dripping from the clutch housing
after extended operation. If the leak is severe, it may
also contaminate the clutch disc causing slip, grab
and chatter.
Transmissions filled from air or electrically pow-
ered lubricant containers can be underfilled. This
Fig. 3 AX 15 Shift Pattern
Fig. 4 Fill Plug Location
Fig. 5 Drain Plug/Backup Light Switch Location
21 - 34 AX 15 MANUAL TRANSMISSIONJ
VALVE BODY ASSEMBLY AND ADJUSTMENT
CAUTION: Do not force valves or plugs into place
during reassembly. If the valve body bores, valves
and plugs are free of distortion or burrs, the valve
body components should all slide into place easily.
In addition, do not overtighten the transfer plate
and valve body screws during reassembly. Over-
tightening can distort the valve body resulting in
valve sticking, cross leakage and unsatisfactory op-
eration. Tighten valve body screws to recom-
mended torque only.
(1) Lubricate valve body bores, valves and plugs
with Mopar ATF Plus transmission fluid.
(2) Insert rear clutch and rear servo check balls in
transfer plate (Fig. 120).
(3) Install filter screen in separator plate (Fig.
120).
(4) Align and install separator plate on transfer
plate. Verify check ball position before installing sep-
arator plate on transfer plate.
(5) Install new O-ring on converter clutch solenoid
and insert solenoid in separator plate (Fig. 120).
Then secure solenoid in position with attaching
screw. Tighten screw to 4 Nzm 35 in. lbs.) torque.
(6) Position valve body so internal passages and
check ball seats are facing upward. Then install
check balls in valve body (Fig. 121). There are a total
of seven check balls; The one large check ball is ap-
proximately 11/32 inch in diameter. The remaining
check balls are approximately 1/4 inch in diameter.
Note that check balls will be steel on some very early
production models and plastic on later production
models.
(7) Align and install assembled transfer and sepa-
rator plates on valve body. Install and tighten valve
body screws alternately in a diagonal pattern to 4
Nzm (35 in. lbs.) torque.
(8) Assemble and install lockup module and compo-
nents on valve body (Fig. 122).
(9) Assemble regulator valve line pressure plug,
sleeve, throttle plug and spring (Fig. 113). Insert as-sembly in valve body and install end plate. Tighten
end plate screws to 4 Nzm (35 in. lbs.) torque.
(10) Install 1-2 and 2-3 shift valves and springs
(Fig. 118).
(11) Install 1-2 shift control valve and spring (Fig.
118)
(12) Install shuttle valve as follows:
(a) Insert shuttle valve in bore.
(b) Insert plastic guides in shuttle valve second-
ary spring.
(c) Install spring on end of valve.
(d) Hold shuttle valve in place. Then compress
secondary spring and install E-clip in groove at end
of valve.
(e) Verify that spring and E-clip are properly
seated before proceeding.
(13) Install shuttle valve cover plate (Fig. 118).
Tighten end plate screws to 4 Nzm (35 in. lbs.)
torque.
(14) Install 1-2 and 2-3 valve governor plugs in
valve body (Fig. 113). Then install shuttle valve pri-
mary spring and throttle plug.
(15) Align and install governor plug end plate on
valve body and install end plate screws. Tighten
screws to 4 Nzm (35 in. lbs.) torque.
(16) Install manual valve (Fig. 117).
(17) Install throttle valve and spring. Then install
kickdown valve and detent (Fig. 117).
(18) Install pressure regulator valve and switch
valve in valve body.
(19) Install manual lever detent spring in housing.
Place detent ball on end of spring and push ball and
spring into housing. Secure ball and spring with De-
tent Retainer 6583 (Fig. 108).
Fig. 120 Installing Converter Clutch Solenoid
Fig. 121 Correct Position Of Valve Body Check Balls
J30RH/32RH TRANSMISSION OVERHAUL 21 - 153
(6) Verify that reaction shaft support hub seal
rings are hooked together (Fig. 155).
(7) Coat front clutch thrust washer with petroleum
jelly to hold it in place. Then install washer over re-
action shaft hub and seat it on pump (Fig. 156).
CAUTION: The thrust washer bore (I.D.), is cham-
fered on one side. Make sure the chamfered side is
installed so it faces the pump.(8) Thread two Pilot Stud Tools C-3288-B into bolt
holes in oil pump flange (Fig. 157).
(9) Align and install oil pump gasket (Fig. 157).
(10) Lubricate oil pump seals with Mopar Door-
Ease, or Ru-Glyde, Door Eze, or ATF Plus.
(11) Install oil pump (Fig. 158). Align and position
pump on pilot studs. Slide pump down studs and
work it into front clutch hub and case by hand. Then
install two or three pump bolts to hold pump in
place.
(12) Remove pilot stud tools and install remaining
oil pump bolts. Tighten bolts alternately in diagonal
pattern to 20 Nzm (15 ft-lbs).
CHECKING INPUT SHAFT END PLAY
(1) Measure input shaft end play (Fig. 159).
(2) Attach dial indicator to converter housing. Po-
sition indicator plunger against input shaft and zero
indicator.
Fig. 153 Front Band Linkage Installation
Fig. 154 Installing Front Band Pivot Pin Access Plug
Fig. 155 Reaction Shaft Support Seal Rings
Fig. 156 Front Clutch Thrust Washer Installation
Fig. 157 Installing Pilot Studs And Oil Pump Gasket
21 - 162 30RH/32RH TRANSMISSION OVERHAULJ