clutch CHRYSLER CARAVAN 2003 Service Manual

²All monitored components (refer to the Emission
section for On-Board Diagnostics).
The PCM compares the upstream and downstream
heated oxygen sensor inputs to measure catalytic
convertor efficiency. If the catalyst efficiency drops
below the minimum acceptable percentage, the PCM
stores a diagnostic trouble code in memory, after 2
trips.
During certain idle conditions, the PCM may enter
a variable idle speed strategy. During variable idle
speed strategy the PCM adjusts engine speed based
on the following inputs.
²A/C status
²Battery voltage
²Battery temperature or Calculated Battery Tem-
perature
²Engine coolant temperature
²Engine run time
²Inlet/Intake air temperature
²Vehicle mileage
ACCELERATION MODE
This is a CLOSED LOOP mode. The PCM recog-
nizes an abrupt increase in Throttle Position sensor
output voltage or MAP sensor output voltage as a
demand for increased engine output and vehicle
acceleration. The PCM increases injector pulse width
in response to increased fuel demand.
²Wide Open Throttle-open loop
DECELERATION MODE
This is a CLOSED LOOP mode. During decelera-
tion the following inputs are received by the PCM:
²A/C status
²Battery voltage
²Inlet/Intake air temperature
²Engine coolant temperature
²Crankshaft position (engine speed)
²Exhaust gas oxygen content (upstream heated
oxygen sensor)
²Knock sensor
²Manifold absolute pressure
²Throttle position sensor
²IAC motor (solenoid) control changes in response
to MAP sensor feedback
The PCM may receive a closed throttle input from
the Throttle Position Sensor (TPS) when it senses an
abrupt decrease in manifold pressure. This indicates
a hard deceleration (Open Loop). In response, the
PCM may momentarily turn off the injectors. This
helps improve fuel economy, emissions and engine
braking.
WIDE-OPEN-THROTTLE MODE
This is an OPEN LOOP mode. During wide-open-
throttle operation, the following inputs are used by
the PCM:
²Inlet/Intake air temperature
²Engine coolant temperature
²Engine speed
²Knock sensor
²Manifold absolute pressure
²Throttle position
When the PCM senses a wide-open-throttle condi-
tion through the Throttle Position Sensor (TPS) it de-
energizes the A/C compressor clutch relay. This
disables the air conditioning system and disables
EGR (if equipped).
The PCM adjusts injector pulse width to supply a
predetermined amount of additional fuel, based on
MAP and RPM.
IGNITION SWITCH OFF MODE
When the operator turns the ignition switch to the
OFF position, the following occurs:
²All outputs are turned off, unless 02 Heater
Monitor test is being run. Refer to the Emission sec-
tion for On-Board Diagnostics.
²No inputs are monitored except for the heated
oxygen sensors. The PCM monitors the heating ele-
ments in the oxygen sensors and then shuts down.
FUEL CORRECTION or ADAPTIVE MEMORIES
DESCRIPTION
In Open Loop, the PCM changes pulse width with-
out feedback from the O2 Sensors. Once the engine
warms up to approximately 30 to 35É F, the PCM
goes into closed loopShort Term Correctionand
utilizes feedback from the O2 Sensors. Closed loop
Long Term Adaptive Memoryis maintained above
170É to 190É F unless the PCM senses wide open
throttle. At that time the PCM returns to Open Loop
operation.
OPERATION
Short Term
The first fuel correction program that begins func-
tioning is the short term fuel correction. This system
corrects fuel delivery in direct proportion to the read-
ings from the Upstream O2 Sensor.
The PCM monitors the air/fuel ratio by using the
input voltage from the O2 Sensor. When the voltage
reaches its preset high or low limit, the PCM begins
to add or remove fuel until the sensor reaches its
switch point. The short term corrections then begin.
The PCM makes a series of quick changes in the
injector pulse-width until the O2 Sensor reaches its
14 - 20 FUEL INJECTIONRS
FUEL INJECTION (Continued)
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OPERATION
NEUTRAL
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. Since
no synchronizers are engaged on either the input or
intermediate shafts, power is not transmitted to the
intermediate shaft and the differential does not turn
(Fig. 3).
Fig. 3 Neutral Gear Operation
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1ST GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft first gear is integral to the input shaft,
and is in constant mesh with the intermediate shaft
first speed gear. Because of this constant mesh, the
intermediate shaft first speed gear freewheels untilfirst gear is selected. As the gearshift lever is moved
to the first gear position, the 1-2 fork moves the 1-2
synchronizer sleeve towards first gear on the inter-
mediate shaft. The synchronizer sleeve engages the
first gear clutch teeth, fixing the gear to the interme-
diate shaft, and allowing power to transmit through
the intermediate shaft to the differential (Fig. 4).
Fig. 4 1st Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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2ND GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft second gear is integral to the input shaft,
and is in constant mesh with the intermediate shaft
second speed gear. Because of this constant mesh,
the intermediate shaft second speed gear freewheels
until second gear is selected. As the gearshift lever ismoved to the second gear position, the 1-2 fork moves
the 1-2 synchronizer sleeve towards second gear on
the intermediate shaft. The synchronizer sleeve
engages the second gear clutch teeth, fixing the gear
to the intermediate shaft, and allowing power to
transmit through the intermediate shaft to the differ-
ential (Fig. 5).
Fig. 5 2nd Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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3RD GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft third speed gear is in constant mesh with
the intermediate shaft 3-4 cluster gear, which is fixed
to the intermediate shaft. Because of this constant
mesh, the input shaft third speed gear freewheelsuntil third gear is selected. As the gearshift lever is
moved to the third gear position, the 3-4 fork moves
the 3-4 synchronizer sleeve towards third gear on the
input shaft. The synchronizer sleeve engages the
third gear clutch teeth, fixing the gear to the input
shaft, and allowing power to transmit through the
intermediate shaft to the differential (Fig. 6).
Fig. 6 3rd Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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4TH GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft fourth speed gear is in constant mesh
with the intermediate shaft 3-4 cluster gear, which is
fixed to the intermediate shaft. Because of this con-
stant mesh, the input shaft fourth speed gear free-
wheels until fourth gear is selected. As the gearshiftlever is moved to the fourth gear position, the 3-4
fork moves the 3-4 synchronizer sleeve towards
fourth gear on the input shaft. The synchronizer
sleeve engages the fourth gear clutch teeth, fixing
the gear to the input shaft, and allowing power to
transmit through the intermediate shaft to the differ-
ential (Fig. 7).
Fig. 7 4th Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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5TH GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft fifth gear is pressed on to the input shaft,
and is in constant mesh with the intermediate shaft
fifth speed gear. Because of this constant mesh, the
intermediate shaft fifth speed gear freewheels untilfifth gear is selected. As the gearshift lever is moved
to the fifth gear position, the 5-R fork moves the 5-R
synchronizer sleeve towards the intermediate shaft
fifth speed gear. The synchronizer sleeve engages the
fifth gear clutch teeth, fixing the gear to the input
shaft, and allowing power to transmit through the
intermediate shaft to the differential (Fig. 8).
Fig. 8 5th Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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REVERSE GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft reverse gear is integral to the input
shaft, and is in constant mesh with the reverse idler
gear. The reverse idler gear, which reverses the rota-
tion of the intermediate shaft, is in constant mesh
with the intermediate shaft reverse gear. Because of
this constant mesh, the intermediate shaft reverse
gear freewheels until reverse gear is selected. As the
gearshift lever is moved to the reverse gear position,
the 5-R fork moves the 5-R synchronizer sleeve
towards the intermediate shaft reverse gear. The
synchronizer sleeve engages the reverse gear clutch
teeth, fixing the gear to the intermediate shaft, and
allowing power to transmit through the intermediate
shaft to the differential (in reverse) (Fig. 9).
DIAGNOSIS AND TESTING - COMMON
PROBLEM CAUSES
The majority of transaxle malfunctions are a result
of:
²Insufficient lubrication
²Incorrect lubricant
²Misassembled or damaged internal components
²Improper operation
HARD SHIFTING
Hard shifting may be caused by a misadjusted
crossover cable. If hard shifting is accompanied by
gear clash, synchronizer clutch and stop rings or gear
teeth may be worn or damaged.
Hard shifting may also be caused by a binding or
broken shift cover mechanism. Remove shift cover
and verify smooth operation. Replace as necessary.
Fig. 9 Reverse Gear Operation
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Misassembled synchronizer components also cause
shifting problems. Incorrectly installed synchronizer
sleeves, keys, balls, or springs can cause shift prob-
lems.
NOISY OPERATION
Transaxle noise is most often a result of worn or
damaged components. Chipped, broken gear or syn-
chronizer teeth, and brinnelled, spalled bearings all
cause noise.
Abnormal wear and damage to the internal compo-
nents is frequently the end result of insufficient
lubricant.
SLIPS OUT OF GEAR
Transaxle disengagement may be caused by mis-
aligned or damaged shift components, or worn teeth
on the drive gears or synchronizer components. Incor-
rect assembly also causes gear disengagement. Check
for missing snap rings.
LOW LUBRICANT LEVEL
Insufficient transaxle lubricant is usually the
result of leaks, or inaccurate fluid level check or refill
method. Leakage is evident by the presence of oil
around the leak point. If leakage is not evident, the
condition is probably the result of an underfill.
If air±powered lubrication equipment is used to fill
a transaxle, be sure the equipment is properly cali-
brated. Equipment out of calibration can lead to an
underfill condition.
CLUTCH PROBLEMS
Worn, damaged, or misaligned clutch components
can cause difficult shifting, gear clash, and noise.
A worn or damaged clutch disc, pressure plate, or
release bearing can cause hard shifting and gear
clash.
REMOVAL
REMOVAL - 2.4L GAS
(1) Raise hood.
(2) Disconnect gearshift cables from shift levers/
cover assembly (Fig. 10).
(3) Remove gearshift cable retaining clips from
mounting bracket (Fig. 10). Remove cables and
secure out of way.
(4) Remove three (3) right engine mount bracket-
to-transaxle bolts (Fig. 11).
(5) Raise vehicle on hoist.
(6) Remove front wheel/tires and halfshafts.
(7) Drain transaxle fluid into suitable container.
(8) Remove front harness retainer and secure har-
ness out of way.
Fig. 10 Gearshift Cables at Transaxle
1 - SELECTOR CABLE
2 - CABLE RETAINER
3 - CABLE RETAINER
4 - CROSSOVER CABLE
5 - MOUNT BRACKET
Fig. 11 Transaxle Right Mount and Bracket
1 - MOUNT BRACKET
2 - BOLT (3)
3 - MOUNT
4 - BOLT (1)
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(9) Using Tool 6638A, disconnect clutch hydraulic
circuit quick connect (located on slave cylinder tube).
Remove clutch slave cylinder by depressing towards
case and rotating counter-clockwise 60É, while lifting
anti-rotation tab out of case slot with screwdriver
(Fig. 12).
(10) Remove engine left mount bracket.
(11) Remove starter motor (Fig. 13).
(12) Disconnect back-up lamp switch connector.
(13) Remove structural collar.
(14) Remove modular clutch assembly-to-drive
plate bolts.
(15) Position screw jack and wood block to engine
oil pan.
(16) Remove transmission upper mount through-
bolt from left frame rail.
(17) Lower engine/transaxle assembly on screw
jack.
(18) Remove four (4) upper mount-to-transaxle
bolts and remove mount (Fig. 14).
(19) Obtain helper and transmission jack. Secure
transaxle to transmission jack and remove transaxle-
to-engine bolts.
(20) Remove transaxle from engine.
(21) Inspect modular clutch assembly, clutch
release components, and engine drive plate.
Fig. 12 Slave Cylinder Removal/Installation
1 - MOUNTING HOLE
2 - SLAVE CYLINDER
3 - ACCESS HOLE
4 - NYLON ANTI-ROTATION TAB
Fig. 13 Starter Motor Removal/Installation
1 - STARTER MOTOR
2 - BOLT (3)
Fig. 14 Transaxle Upper Mount
1 - MOUNT
2 - BOLT (4)
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