1995 JEEP YJ transmission

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

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

(11) Remove lock ball spring with pencil magnet
(Fig. 10).
(12) Remove shift head lock ball with pencil mag-
net (Fig. 11).
(13) Remove adapter housing bolts (Fig. 12).
Fig. 10 Removing/Installing Lock Ball Spring
Fig. 11 Removing/Installing Shift Head Lock Ball
Fig. 12 Adapter Housing Bolt Locations
JAX 15 MANUAL TRANSMISSION 21 - 39

(14) Loosen adapter/extension housing with rubber
mallet (Fig. 13).
(15) Remove housing after loosening it (Fig. 14)
(16) Remove adapter housing oil seal with a pry
tool (Fig. 15).GEAR CASE REMOVAL
(1) Remove bearing retainer bolts and remove re-
tainer (Fig. 16).
(2) Remove retainer oil seal with pry tool (Fig. 17).
(3) Remove input shaft bearing snap ring (Fig. 18).
Fig. 15 Removing Adapter Housing Seal
Fig. 13 Loosening Adapter Housing
Fig. 14 Adapter Housing Removal
Fig. 16 Front Bearing Retainer Removal
Fig. 17 Front Bearing Retainer Seal Location
Fig. 18 Removing Input Shaft Bearing Snap Ring
21 - 40 AX 15 MANUAL TRANSMISSIONJ