2003 CHRYSLER CARAVAN transmission

²Engine
²Transmission
²Exhaust
²Propeller shaft (vibration)
²Vehicle body (drumming)
Driveline module noises are normally divided into
two categories: gear noise or bearing noise. A thor-
ough and careful inspection should be completed to
determine the actual source of the noise before
replacing the driveline module.
The rubber mounting bushings help to dampen-out
driveline module noise when properly installed.
Inspect to confirm that no metal contact exists
between the driveline module case and the body. The
complete isolation of noise to one area requires
expertise and experience. Identifying certain types of
vehicle noise baffles even the most capable techni-
cians. Often such practices as:
²Increase tire inflation pressure to eliminate tire
noise.
²Listen for noise at varying speeds with different
driveline load conditions
²Swerving the vehicle from left to right to detect
wheel bearing noise.
All driveline module assemblies produce noise to a
certain extent. Slight carrier noise that is noticeable
only at certain speeds or isolated situations should be
considered normal. Carrier noise tends to peak at a
variety of vehicle speeds. Noise isNOT ALWAYSan
indication of a problem within the carrier.
TIRE NOISE
Tire noise is often mistaken for driveline module
noise. Tires that are unbalanced, worn unevenly or
are worn in a saw-tooth manner are usually noisy.
They often produce a noise that appears to originate
in the driveline module.
Tire noise changes with different road surfaces, but
driveline module noise does not. Inflate all four tires
with approximately 20 psi (138 kPa) more than the
recommended inflation pressure (for test purposes
only). This will alter noise caused by tires, but will
not affect noise caused by the differential. Rear axle
noise usually ceases when coasting at speeds less
than 30 mph (48 km/h); however, tire noise contin-
ues, but at a lower frequency, as the speed is
reduced.
After test has been completed lower tire pressure
back to recommended pressure.
GEAR NOISE (DRIVE PINION AND RING GEAR)
Abnormal gear noise is rare and is usually caused
by scoring on the ring gear and drive pinion. Scoring
is the result of insufficient or incorrect lubricant in
the carrier housing.Abnormal gear noise can be easily recognized. It
produces a cycling tone that will be very pronounced
within a given speed range. The noise can occur dur-
ing one or more of the following drive conditions:
²Drive
²Road load
²Float
²Coast
Abnormal gear noise usually tends to peak within
a narrow vehicle speed range or ranges. It is usually
more pronounced between 30 to 40 mph (48 to 64
km/h) and 50 to 60 mph (80 to 96 km/h). When objec-
tionable gear noise occurs, note the driving condi-
tions and the speed range.
BEARING NOISE (DRIVE PINION AND
DIFFERENTIAL)
Defective bearings produce a rough growl that is
constant in pitch and varies with the speed of vehi-
cle. Being aware of this will enable a technician to
separate bearing noise from gear noise.
Drive pinion bearing noise that results from defec-
tive or damaged bearings can usually be identified by
its constant, rough sound. Drive pinion front bearing
is usually more pronounced during a coast condition.
Drive pinion rear bearing noise is more pronounced
during a drive condition. The drive pinion bearings
are rotating at a higher rate of speed than either the
differential side bearings or the axle shaft bearing.
Differential side bearing noise will usually produce
a constant, rough sound. The sound is much lower in
frequency than the noise caused by drive pinion bear-
ings.
Bearing noise can best be detected by road testing
the vehicle on a smooth road (black top). However, it
is easy to mistake tire noise for bearing noise. If a
doubt exists, the tire treads should be examined for
irregularities that often causes a noise that resem-
bles bearing noise.
ENGINE AND TRANSMISSION NOISE
Sometimes noise that appears to be in the driv-
eline module assembly is actually caused by the
engine or the transmission. To identify the true
source of the noise, note the approximate vehicle
speed and/or RPM when the noise is most noticeable.
Stop the vehicle next to a flat brick or cement wall
(this will help reflect the sound). Place the transaxle
inNEUTRAL. Accelerate the engine slowly up
through the engine speed that matches the vehicle
speed noted when the noise occurred. If the same
noise is produced, it usually indicates that the noise
is being caused by the engine or transaxle.
RSREAR DRIVELINE MODULE3-25
REAR DRIVELINE MODULE (Continued)
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DIAGNOSIS AND TESTING - REAR DRIVELINE
MODULE OPERATION
Driveline module operation requires relatively
straight-forward diagnosis. Refer to the following
chart:
DRIVELINE MODULE DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
Rear wheels not
overrunning1) Bi-directional overrunning clutch
failure1) Replace overrunning clutch
components as required
No AWD in forward or
reverse directions, propeller
shaft turning1) Bi-directional overrunning clutch
failure1) Replace overrunning clutch
components as required
2) Viscous coupling failure 2) Replace viscous coupling
3) Rear differential failure 3) Replace the rear differential
assembly
No AWD in forward or
reverse directions, propeller
shaft not turning1) Power transfer unit failure. 1) Replace power transfer unit
components as necessary
Vibration at all speeds,
continuous torque transfer1) Mis-matched tires, worn tires on
front axle.1) Replace worn or incorrect
(mis-matched) tires with same
make and size
REMOVAL
(1) Raise vehicle on hoist.
(2) Drain fluid from overrunning clutch housing
and/or differential assembly if necessary.
(3) Remove propeller shaft. (Refer to 3 - DIFFER-
ENTIAL & DRIVELINE/PROPELLER SHAFT -
REMOVAL)
(4) Disconnect left and right rear halfshafts from
output flanges (Fig. 2).
(5) Remove torque arm mount to body bolts.(6) Position transmission jack to driveline module
assembly and secure assembly to jack.
(7) Remove two driveline module-to-body bolts
(Fig. 3).
(8) Lower driveline module from vehicle and
remove from jack.
Fig. 2 Half Shaft Mounting Bolts
1 - SHAFT
2 - FLANGE
Fig. 3 Rear Drive Line Module Assembly Mounting
Bolts
1 - DRIVELINE MODULE RETAINING BOLT (2)
2 - RUBBER ISOLATOR
3 - WASHER
3 - 26 REAR DRIVELINE MODULERS
REAR DRIVELINE MODULE (Continued)
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(14) Install torque arm assembly into position.
Install and torque torque arm-to-differential assem-
bly bolts (Fig. 25) to 60 N´m (44 ft. lbs.).
INSTALLATION
(1) Install rear driveline module assembly to
transmission jack and secure.
(2) Raise rear driveline module into position and
install and torque mounting bolts (Fig. 26) to 54 N´m
(40 ft. lbs.).(3) Remove transmission jack.
(4) Install and torque torque arm mount-to-body
bolts to 54 N´m (40 ft. lbs.).
(5) Install halfshafts to differential output flanges
and torque bolts (Fig. 27) to 61 N´m (45 ft. lbs.).
(6) Install propeller shaft. (Refer to 3 - DIFFER-
ENTIAL & DRIVELINE/PROPELLER SHAFT -
INSTALLATION)
(7) Lower vehicle.
Fig. 25 Torque Arm Fasteners
1 - TORQUE ARM ASSEMBLY
2 - BOLT (SIX)
Fig. 26 Rear Drive Line Module Assembly Rear
Mounting Bolts
1 - DRIVELINE MODULE RETAINING BOLT (2)
2 - RUBBER ISOLATOR
3 - WASHER
Fig. 27 Half Shaft Mounting Bolts
1 - SHAFT
2 - FLANGE
RSREAR DRIVELINE MODULE3-33
REAR DRIVELINE MODULE (Continued)
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SPECIFICATIONS - REAR DRIVELINE MODULE
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Bolt, Driveline Module-to-Body 54 40 Ð
Bolt, Halfshaft-to-Ouput Flange 61 45 Ð
Bolt, Overrunning Clutch Housing-to-Differential 60 44 Ð
Bolt, Torque Arm-to-Differential Assembly 60 44 Ð
Bolt, Torque Arm Mount-to-Body 54 40 Ð
Nut, Input Flange 135 100 Ð
Plug, Differential Drain/Fill 35 26 Ð
Plug, Overrunning Clutch Housing Drain/Fill 30 22 Ð
Vent, Differential/Overrunning Clutch Housing 12 Ð 110
SPECIAL TOOLSBI-DIRECTIONAL
OVERRUNNING CLUTCH
DESCRIPTION
The bi-directional overrunning clutch (BOC) (Fig.
28) works as a mechanical disconnect between the
front and rear axles, preventing torque from being
transferred from the rear axle to the front. The BOC
is a simply an overrunning clutch which works in
both clockwise and counter-clockwise rotations. This
means that when the output (the rear axle) is rotat-
ing faster in one direction than the input (front axle),
there is no torque transmission. But when the input
speed is equal to the output speed, the unit becomes
locked. The BOC provides significant benefits regard-
ing braking stability, handling, and driveline durabil-
ity. Disconnecting the front and the rear driveline
during braking helps to maintain the braking stabil-
ity of an AWD vehicle. In an ABS/braking event, the
locking of the rear wheels must be avoided for stabil-
ity reasons. Therefore brake systems are designed to
lock the front wheels first. Any torque transfer from
the rear axle to the front axle disturbs the ABS/brak-
ing system and causes potential instabilities on a
slippery surface. The BOC de-couples the rear driv-
eline as soon the rear wheels begin to spin faster
than the front wheels (front wheels locked) in order
to provide increased braking stability. Furthermore
the BOC also reduces the likelihood of throttle off
over-steer during cornering. In a throttle off maneu-
ver, the BOC once again de-couples the rear driveline
forcing all the engine brake torque to the front
wheels. This eliminates the chance of lateral slip on
the rear axle and increases it on the front. The vehi-
cle will therefore tend to understeer, a situation
which is considered easier to manage in most circum-
stances. During this maneuver, and during the ABS
braking event, the BOC does not transmit torque
Tool 6958
Tool 8493
Tool 8802
3 - 34 REAR DRIVELINE MODULERS
REAR DRIVELINE MODULE (Continued)
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OPERATION
In order to achieve all-wheel drive operation in
reverse, the overrunning clutch locking functional
direction must be reversible. The bi-directional over-
running clutch (BOC) changes the operational mode
direction depending on the propeller shaft direction.
The propeller shaft rotates in the clockwise (when
viewed from the front) direction when the vehicle is
moving forward, which indexes the BOC to the for-
ward overrunning position. When the vehicle is in
reverse, the propeller shaft will rotate counter-clock-
wise and index the BOC to the reverse overrunning
position.
The BOC acts as a mechanical stator. It is active
(transmitting torque), or it is not active and in over-
running mode (not transmitting torque). This ªall or
nothingº approach to torque transfer would cause a
sudden application of all available power to the rear
wheels, which is not desirable. Therefore it is run in
series with a viscous coupler to smooth, dampen, and
limit the transmission of torque to the rear axle and
to prevent a step style torque input to the rear axle.
STEADY STATE, LOW TO MODERATE SPEED, NO
FRONT WHEEL SLIP, FORWARD DIRECTION
During normal driving conditions, (no wheel slip),
the inner shaft (front axle) and outer race (viscous
coupler) are running at different speeds due to the
different gear ratios between the front and rear dif-
ferentials. In this condition, the outer race is always
spinning faster (overdriving between 5-32 rpm) than
the inner shaft. When the BOC (Fig. 29) is running
under these conditions, at low vehicle speeds the
drag shoes and the cage keep the rollers up on the
left side (forward side) of the inner shaft flats. This is
what is known as ªoverrunning mode.º Notice that
when the clutch is in overrunning mode, the rollers
are spinning clockwise and with the outer race, thus
no torque is being transferred.
NOTE: Low speed, forward and reverse operation is
identical, just in opposite directions. (Fig. 29)
shows forward direction in reverse the rollers are
on the other side of the flats due to a reversal of
the cage force.
TRANSIENT CONDITION (BOC LOCKED), FRONT
WHEEL SLIP, FORWARD DIRECTION
When the front wheels lose traction and begin to
slip, the propeller shaft and rear axle pinion speed
difference decreases to zero. At this point the input
shaft (cam) becomes the driving member of the BOC
(Fig. 30), compressing the rollers against the outer
race. This locks the input shaft with the outer race
and transmits torque to the housing of the viscous
coupler, that in turn transmits torque to the rear
axle pinion. It should also be noted that when the
device is locked, the inner shaft and the outer race
are rotating at the same speed. The rollers are
pinched at this point and will stay locked until a
torque reversal (no front wheel slip) occurs. When
locked, the viscous coupler slips during the torque
transfer and the amount of torque transferred is
dependent on the coupling characteristic and the
amount of front wheel slip.
Fig. 29 BOC Operation at Low Speeds With No
Front Wheel Slip
1 - CAGE
2 - ROLLER
3 - INPUT SHAFT
3 - 36 REAR DRIVELINE MODULERS
BI-DIRECTIONAL OVERRUNNING CLUTCH (Continued)
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(5) Re-position the drain pan under the differential
fill plug.
(6) Remove the differential fill plug (Fig. 41).
(7) Using a suction gun (Fig. 42) or equivalent, fill
the differential assembly with 0.7 L (1.48 pts.) of
MopartGear and Axle Lubricant (80W-90).
(8) Install the fill plug and torque to 35 N´m (26 ft.
lbs.).
FLUID - OVERRUNNING
CLUTCH HOUSING
STANDARD PROCEDURE - OVERRUNNING
CLUTCH HOUSING FLUID CHANGE
(1) Raise vehicle on hoist.
(2) Position a drain pan under overrunning clutch
housing drain plug.
(3) Remove overrunning clutch housing drain plug
and drain fluid (Fig. 43).
(4) Install the drain plug and torque to 30 N´m (22
ft. lbs.).
(5) Re-position the drain pan under the overrun-
ning clutch housing fill plug.
(6) Remove fill plug (Fig. 44).
(7) Using a suction gun (Fig. 45), add 0.58 L (1.22
pts.) of MopartATF+4 (Automatic Transmission Flu-
idÐType 9602).
(8) Install fill plug and torque to 30 N´m (22 ft.
lbs.).
VISCOUS COUPLER
DESCRIPTION
The heart of the all-wheel drive system is the
inter-axle viscous coupling and bi-directional over-
running clutch. Under normal driving the vehicle
retains predominantly front wheel drive characteris-
tics. The all-wheel drive takes effect when the front
wheels start to slip. Under normal level road,
straight line driving, 100% of the torque is allocated
to the front wheels. The viscous coupler allows more
Fig. 42 Filling Differential
1 - DIFFERENTIAL ASSEMBLY
2 - SUCTION GUN
Fig. 43 Overrunning Clutch Case Drain Plug
1 - OVERRUNNING CLUTCH HOUSING DRAIN PLUG
Fig. 44 Overrunning Clutch Housing Fill Plug
1 - OVERRUNNING CLUTCH HOUSING FILL PLUG
2 - FUEL TANK
RSREAR DRIVELINE MODULE3-41
FLUID - DIFFERENTIAL ASSEMBLY (Continued)
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RED BRAKE WARNING INDICATOR LAMP
CONDITION POSSIBLE CAUSES CORRECTION
RED BRAKE WARNING
LAMP ON1. Parking brake lever not fully
released.1. Release parking brake lever.
2. Parking brake warning lamp
switch on parking brake lever.2. Inspect and replace switch as necessary.
3. Brake fluid level low in reservoir. 3. Fill reservoir. Check entire system for
leaks. Repair or replace as required.
4. Brake fluid level switch. 4. Disconnect switch wiring connector. If
lamp goes out, replace switch.
5. Mechanical instrument cluster
(MIC) problem.5. Refer to appropriate Diagnostic
information.
6. Amber ABS Warning Indicator
Lamp also illuminated.6. Refer to appropriate Diagnostic
information.
BRAKE NOISE
CONDITION POSSIBLE CAUSES CORRECTION
CLICK OR SQUAWK ON
PEDAL APPLICATION1. Brake lamp switch. 1. Replace switch.
2. Brake Transmission Shift Interlock
Linkage.2. Lubricate BTSI linkage.
3. Pedal pivot bushings 3. Lubricate pivot bushings. Replace if
necessary.
DISC BRAKE CHIRP 1. Excessive brake rotor runout. 1. Follow brake rotor diagnosis and testing.
Correct as necessary.
2. Lack of lubricant on brake caliper
slides.2. Lubricate brake caliper slides.
3. Caliper/shoes not fully seated. 3. Reseat caliper/shoes.
DISC BRAKE RATTLE OR
CLUNK1. Broken or missing anti-rattle
spring clips on shoes.1. Replace brake shoes.
2. Caliper guide pins/bolts loose. 2. Tighten guide pins/bolts.
DISC BRAKE SQUEAK AT
LOW SPEED (WHILE
APPLYING LIGHT BRAKE
PEDAL EFFORT)1. Brake shoe linings. 1. Replace brake shoes.
DRUM BRAKE CHIRP 1. Lack of lubricant on brake shoe
support plate where shoes ride.1. Lubricate shoe contact areas on brake
shoe support plates.
DRUM BRAKE CLUNK 1. Drum(s) have threaded machined
braking surface.1. Replace brake drums as necessary.
DRUM BRAKE HOWL OR
MOAN1. Lack of lubricant on brake shoe
support plate where shoes ride and
at the anchor.1. Lubricate shoe contact areas on brake
shoe support plates and at the anchor.
2. Rear brake shoes. 2. Replace rear brake shoes.
DRUM BRAKE SCRAPING
OR WHIRRING1. ABS wheel speed sensor or tone
wheel.1. Inspect, correct or replace faulty
component(s).
RSBRAKES - BASE5-5
BRAKES - BASE (Continued)
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master cylinder reservoir from completely draining
out.
(3) Disconnect the brake fluid flex hose from the
caliper assembly and remove it from the vehicle.
CAUTION: Do not use excessive force when clamp-
ing caliper in vise. Excessive vise pressure will
cause bore distortion.
(4) Mount the caliper in a vise equipped with pro-
tective jaws.
(5) Remove the piston dust boot from the caliper
and discard.
NOTE: Do not use a screw driver or other metal tool
for seal removal. Using such tools can scratch the
bore or leave burrs on the seal groove edges.
(6) Using a soft tool such as a plastic trim stick,
work the piston seal out of its groove in caliper pis-
ton bore (Fig. 33). Discard the old seal.
(7) Clean the piston bore and drilled passage ways
using alcohol or a suitable solvent. Wipe it dry using
only a lint-free cloth.
(8) Inspect the piston bore for scoring or pitting.
Bores that show light scratches or corrosion can usu-
ally be cleared of the light scratches or corrosion
using crocus cloth.CLEANING - CALIPER
WARNING: DUST AND DIRT ACCUMULATING ON
BRAKE PARTS DURING NORMAL USE MAY CON-
TAIN ASBESTOS FIBERS FROM PRODUCTION OR
AFTERMARKET BRAKE LININGS. BREATHING
EXCESSIVE CONCENTRATIONS OF ASBESTOS
FIBERS CAN CAUSE SERIOUS BODILY HARM.
EXERCISE CARE WHEN SERVICING BRAKE
PARTS. DO NOT SAND OR GRIND BRAKE LINING
UNLESS EQUIPMENT USED IS DESIGNED TO CON-
TAIN THE DUST RESIDUE. DO NOT CLEAN BRAKE
PARTS WITH COMPRESSED AIR OR BY DRY
BRUSHING. CLEANING SHOULD BE DONE BY
DAMPENING THE BRAKE COMPONENTS WITH A
FINE MIST OF WATER, THEN WIPING THE BRAKE
COMPONENTS CLEAN WITH A DAMPENED CLOTH.
DISPOSE OF CLOTH AND ALL RESIDUE CONTAIN-
ING ASBESTOS FIBERS IN AN IMPERMEABLE
CONTAINER WITH THE APPROPRIATE LABEL. FOL-
LOW PRACTICES PRESCRIBED BY THE OCCUPA-
TIONAL SAFETY AND HEALTH ADMINISTRATION
(OSHA) AND THE ENVIRONMENTAL PROTECTION
AGENCY (EPA) FOR THE HANDLING, PROCESSING,
AND DISPOSING OF DUST OR DEBRIS THAT MAY
CONTAIN ASBESTOS FIBERS.
To clean or flush the internal passages of the brake
caliper, use fresh brake fluid or MopartNon-Chlori-
nated Brake Parts Cleaner. Never use gasoline, ker-
osene, alcohol, oil, transmission fluid or any fluid
containing mineral oil to clean the caliper. These flu-
ids will damage rubber cups and seals.
INSPECTION - CALIPER
Inspect the disc brake caliper for the following:
²Brake fluid leaks in and around boot area and
inboard lining
²Ruptures, brittleness or damage to the piston
dust boot
²Damaged, dry or brittle guide pin dust boots
If caliper fails inspection, disassemble and recondi-
tion caliper, replacing the seals and dust boots.
ASSEMBLY
ASSEMBLY - CALIPER GUIDE PIN BUSHINGS
(DISC/DISC BRAKES)
(1) Fold the guide pin bushing in half lengthwise.
NOTE: To avoid damage to the bushing, do not use
a sharp object to install the guide pin bushing.
(2) Insert the folded bushing into the caliper
mounting boss using your fingers from the rear of
the caliper.
Fig. 33 Removing Piston Seal
1 - PLASTIC TRIM STICK
2 - CALIPER
3 - PISTON SEAL GROOVE
4 - PISTON SEAL
RSBRAKES - BASE5-25
DISC BRAKE CALIPER - FRONT (Continued)
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