1988 JEEP CHEROKEE automatic transmission
[x] Cancel search: automatic transmissionPage 1187 of 1378
Fig. 6: Engine Driveability & Automatic Transmission
Page 1212 of 1378
\003
TR AN SM IS SIO N R EM OVA L & IN STA LLA TIO N - A /T
1988 J e ep C hero ke e
1988 Automatic Transmission Removal
JEEP
TRANSMISSION
ALL MODELS
Removal
1) Disconnect fan shroud and transmission fill tube upper
bracket. Raise vehicle. Remove converter inspection cover and fill
tube. Remove starter.
2) Mark drive shafts for reassembly. Disconnect shafts at
transfer case and wire to frame rails. DO NOT allow shafts to hang
free as damage to universal joints may result. On V8 models,
disconnect exhaust pipes from exhaust manifolds. Drain transfer case
lubricant. Disconnect speedometer cable from transmission.
3) Disconnect all shift and throttle linkages and wiring
from transmission and transfer case. Mark converter drive plate and
converter for reassembly and remove torque converter-to-drive plate
bolts. Rotate crankshaft to gain access to bolts.
4) Support transmission/transfer case assembly with jack and
secure with chain. Remove bolts and rear transmission crossmember.
Lower transmission enough to disconnect cooler lines at transmission.
Remove transmission-to-engine retaining bolts and slowly slide
transmission assembly away from engine.
5) Hold converter in position while lowering transmission
assembly from vehicle. Separate transmission from transfer case.
Installation
To install, reverse removal procedures. DO NOT tighten
exhaust pipe attaching bolts until crossmember has been installed and
transmission jack has been removed. Make sure all index marks made at
removal are aligned. Tighten all bolts to specification and fill
transmission and transfer case with fluid.
TORQUE SPECIFICATIONS
TIGHTENING SPECIFICATIONS \
\
\
\
\
\
\
Application Ft. Lbs. (N.m)\
Cooler Line Nuts ........................................... 25 (34)\
Torque Converter-to-Drive Plate Bolts ...................... 22 (30)\
Transfer Case-to-Transmission Bolts ........................ 40 (54)\
Transmission-to-Engine Bolts ............................... 30 (41)\
\
\
\
\
\
\
\
Page 1215 of 1378
\003
TR AN SM IS SIO N S ER VIC IN G - A /T
1988 J e ep C hero ke e
1988 Automatic Transmission Servicing
JEEP
LUBRICATION
SERVICE INTERVALS
Transmission
Check fluid level and condition of fluid at each engine oil
change. Under normal, light duty operating conditions, change fluid,
replace filter and adjust bands every 2 yrs. or 25,000 miles. Under
heavy duty service, change fluid, replace filter and adjust bands
every 12 months or 12,500 miles.
Transfer Case
Check transfer case fluid every 12,000 miles and replace
fluid every 30,000 miles.
CHECKING FLUID LEVEL
Transmission
Park vehicle on a level surface and apply parking brake.
With engine idling at normal operating temperature, move transmission
selector lever through all gears, ending in "N" ("P" for AW-4
transmission). Check fluid level. Fluid level should be between
"FULL" and "ADD ONE PINT" mark on dipstick. Add fluid as needed. DO
NOT overfill.
Transfer Case
Remove fill plug. Check oil level. If level is not up to
fill plug opening, add lubricant until it is.
RECOMMENDED FLUID
Both transmissions and transfer cases use DEXRON-II ATF.
FLUID CAPACITY
NOTE: Transmission and converter capacities are approximate. Fluid
level should always be determined by reading on dipstick,
rather than amount of fluid added.
TRANSMISSION REFILL CAPACITIES
\
\
\
\
\
\
\
Application Quantity
All Models
Including Converter ................................ 8.5 qts. (8.0L)\
Without Converter .................................. 4.3 qts. (4.0L)\
\
\
\
\
\
\
\
TRANSFER CASE REFILL CAPACITIES \
\
\
\
\
\
\
Application Capacity
Model 207 ............................................ 4.5 pts. (2.1L)\
Model 208 ............................................ 6.0 pts. (2.8L)\
Page 1268 of 1378
In certain conditions, the pitch of the exhaust gases may
sound like gear whine. At other times, it may be mistaken for a wheel
bearing rumble.
Tires, especially radial and snow, can have a high-pitched
tread whine or roar, similar to gear noise. Also, some non-standard
tires with an unusual tread construction may emit a roar or whine.
Defective CV/universal joints may cause clicking noises or
excessive driveline play that can be improperly diagnosed as drive
axle problems.
Trim and moldings also can cause a whistling or whining
noise. Ensure none of these components are causing the noise before
disassembling the drive axle.
Gear Noise
A "howling" or "whining" noise from the ring and pinion gear
can be caused by an improper gear pattern, gear damage, or improper
bearing preload. It can occur at various speeds and driving
conditions, or it can be continuous.
Before disassembling axle to diagnose and correct gear
noise, make sure that tires, exhaust, and vehicle trim have been
checked as possible causes.
Chuckle
This is a particular rattling noise that sounds like a stick
against the spokes of a spinning bicycle wheel. It occurs while
decelerating from 40 MPH and usually can be heard until vehicle comes
to a complete stop. The frequency varies with the speed of the
vehicle.
A chuckle that occurs on the driving phase is usually caused
by excessive clearance due to differential gear wear, or by a damaged
tooth on the coast side of the pinion or ring gear. Even a very small
tooth nick or a ridge on the edge of a gear tooth is enough the cause
the noise.
This condition can be corrected simply by cleaning the gear
tooth nick or ridge with a small grinding wheel. If either gear is
damaged or scored badly, the gear set must be replaced. If metal has
broken loose, the carrier and housing must be cleaned to remove
particles that could cause damage.
Knock
This is very similar to a chuckle, though it may be louder,
and occur on acceleration or deceleration. Knock can be caused by a
gear tooth that is damaged on the drive side of the ring and pinion
gears. Ring gear bolts that are hitting the carrier casting can cause
knock. Knock can also be due to excessive end play in the axle shafts.
Clunk
Clunk is a metallic noise heard when an automatic
transmission is engaged in Reverse or Drive, or when throttle is
applied or released. It is caused by backlash somewhere in the
driveline, but not necessarily in the axle. To determine whether
driveline clunk is caused by the axle, check the total axle backlash
as follows:
1) Raise vehicle on a frame or twinpost hoist so that drive
wheels are free. Clamp a bar between axle companion flange and a part
of the frame or body so that flange cannot move.
2) On conventional drive axles, lock the left wheel to keep
it from turning. On all models, turn the right wheel slowly until it
is felt to be in Drive condition. Hold a chalk marker on side of tire
about 12" from center of wheel. Turn wheel in the opposite direction
until it is again felt to be in Drive condition.
3) Measure the length of the chalk mark, which is the total
Page 1289 of 1378
Fig. 3: TBI Idle Speed Control (ISC) Motor Adjustment
Courtesy of Chrysler Motors.
4) Connect ISC motor connector. Turn ignition off for 10
seconds. ISC motor should fully extend. Restart engine. Engine speed
should momentarily be about 3500 RPM and return to idle speed. Turn
ignition off and disconnect tachometer. Apply sealant to adjustment
screw threads. Install air cleaner.
IDLE SPEED (RPM)
\
\
\
\
\
\
\
Application Curb Idle
2.5L TBI (ISC Plunger Extended) ............................... 3500\
\
\
\
\
\
\
\
NOTE: Holding plunger inward may create an intermittent trouble
code in ECU memory. To clear ECU memory, turn ignition off
and disconnect negative battery cable for 10 seconds.
THROTTLE POSITION SENSOR (TPS) ADJUSTMENT
NOTE: On some models, it may be necessary to remove throttle body
from intake manifold, to access sensor wiring harness.
Automatic Transmission
1) Locate the square TPS connector. Note connector terminal
identification stamped on the back of the connector. Turn ignition on.
2) Connect voltmeter through back of wiring harness
Page 1297 of 1378
Fig. 2: 4.0L & 4.2L Timing Marks & Firing Order
Magnetic probe located at 9.5 degrees ATDC on 4.2L.
IGNITION TIMING (4.0L)
Information not available from manufacturer.
IGNITION TIMING (4.2L)
NOTE: Engines are equipped with a receptacle for a magnetic probe
timing light, located 9.5 degrees ATDC. Do not use this
location to check timing with a conventional light, use a
magnetic probe timing light.
Standard Timing Procedure
1) Apply parking brake, and place transmission in Neutral
(Park for automatic transmissions). Operate engine to normal operating\
temperature. Turn ignition off. Install timing light.
2) Connect tachometer. Disconnect and plug vacuum hose at
distributor. Disconnect vacuum switch assembly wire connector, located
on top of valve cover. Start engine and increase engine speed to 1600
RPM.
3) Compare timing to specification. See
IGNITION TIMING SPECIFICATIONS table. To adjust timing, loosen
distributor clamp bolt and turn distributor. Recheck timing after
clamp bolt is tightened.
Alternate Timing Procedure
1) Apply parking brake and place transmission in Neutral
(Drive for automatic transmissions). Operate engine to obtain normal
operating temperature. Turn ignition off. Install timing light.
2) Disconnect and plug vacuum switch hose (Red and Black
Page 1298 of 1378
wires connected to switch). Disconnect distributor vacuum advance hose
and connect hose to vacuum switch. Disconnect wire connector from
knock sensor, located in cylinder head.
3) Using a jumper wire, ground knock sensor wire connector to
engine block. Start engine. With engine at idle speed (solenoid
energized), check timing. Adjust timing to one degree more than
specification (if required). See Emission Control Label.
IGNITION TIMING SPECIFICATIONS (DEGREES BTDC@RPM) - 4.2L
\
\
\
\
\
\
Application Man. Trans. Auto. Trans.
50 State ............. 9 @ 1600 ............... 9 @ 1600
High Altitude ........ 16 @ 1600 ............. 16 @ 1600
\
\
\
\
\
\
HOT (SLOW) IDLE RPM
4.0L
1) Apply parking brake and place transmission in Neutral
(Drive for automatic transmissions). Operate engine to normal
operating temperature. Turn ignition off.
2) Ensure all accessories are off. Connect positive
tachometer lead to terminal "D1-1" and negative lead to "D2-7" of
diagnostic connectors. See Fig. 3. Disconnect air stepper motor
connector and TPS wiring connector. See Fig. 4.
Fig. 3: Diagnostic Connector Terminal Identification
Courtesy of Chrysler Motors.
Page 1300 of 1378
Fig. 5: Adjusting Idle RPM
Courtesy of Chrysler Motors.
6) Adjust idle RPM screw to obtain idle speed of 750F50 RPM.
Once correct idle RPM is obtained, seal the welch plug cavity with RTV
sealant. Reconnect air stepper motor and TPS.
4.2L
1) Warm engine to normal operating temperature. Apply parking
brake. Place automatic transmission in Drive (Neutral on manual
transmission). Disconnect and plug vacuum hose from vacuum actuator.
Disconnect solenoid wire connector.
2) Adjust curb idle screw to obtain correct curb idle. See
CURB IDLE SPEED (RPM) table. Apply 10-15 in. Hg vacuum to vacuum
actuator. With throttle positioner fully extended, adjust screw on
throttle lever, to set vacuum actuator RPM to specification. See
VACUUM ACTUATOR & SOLENOID IDLE (RPM) table. Disconnect vacuum pump.
3) Apply battery voltage to solenoid with a jumper wire. Turn
A/C on (if equipped). Open throttle, allowing solenoid to fully
extend. Adjust solenoid adjusting screw to obtain solenoid idle RPM.