REMOVAL
(1) Disconnect the negative battery cable.
(2) Remove the exhaust heat shield (Fig. 27).
(3) Disconnect the O2 sensor harness connector
(Fig. 27)
(4) Remove the O2 sensor (Fig. 28).
INSTALLATION
(1) Install the oxygen sensor (Fig. 28).
(2) Install the heatshield and tighen fasteners to
9N´m (80 lbs. in.) (Fig. 27).
(3) Properly position the oxygen sensor wiring har-
ness and connect the electrical connector (Fig. 27)
(4) Connect the negative battery cable.
Fig. 27 HEAT SHIELD
1 - FASTENERS
2 - SHIELD
3 - O2 SENSOR HARNESS CONNECTOR
Fig. 28 OXYGEN SENSOR
1 - OXYGEN SENSOR
14 - 48 FUEL INJECTIONVA
TRANSMISSION
TABLE OF CONTENTS
page
AUTOMATIC TRANSMISSION NAG1 - SERVICE
INFORMATION............................1
AUTOMATIC TRANSMISSION NAG1 - SERVICE
INFORMATION
TABLE OF CONTENTS
page page
AUTOMATIC TRANSMISSION NAG1 - SERVICE
INFORMATION
DESCRIPTION..........................3
OPERATION............................4
DIAGNOSIS AND TESTING
AUTOMATIC TRANSMISSION............39
PRELIMINARY........................39
ROAD TESTING......................39
AUTOMATIC TRANSMISSION............40
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR......................42
REMOVAL.............................42
DISASSEMBLY.........................46
ASSEMBLY............................52
INSTALLATION.........................60
SCHEMATICS AND DIAGRAMS............65
SPECIFICATIONS - NAG1 AUTOMATIC
TRANSMISSION......................86
SPECIAL TOOLS - AUTOMATIC
TRANSMISSION - NAG1................87
INPUT CLUTCHES
DESCRIPTION.........................90
OPERATION...........................91
INPUT CLUTCH K1
DISASSEMBLY.........................92
ASSEMBLY............................94
INPUT CLUTCH K2
DISASSEMBLY.........................97
ASSEMBLY............................99
INPUT CLUTCH K3
DISASSEMBLY........................102
ASSEMBLY...........................103
ELECTROHYDRAULIC UNIT
DESCRIPTION........................105
OPERATION..........................112
REMOVAL............................120
DISASSEMBLY........................121
ASSEMBLY...........................125INSTALLATION........................129
FLUID AND FILTER
DESCRIPTION........................131
OPERATION..........................131
DIAGNOSIS AND TESTING
EFFECTS OF INCORRECT FLUID LEVEL . . 131
CAUSES OF BURNT FLUID.............132
FLUID CONTAMINATION...............132
STANDARD PROCEDURE
CHECK OIL LEVEL...................132
TRANSMISSION FILL.................133
FLUID/FILTER SERVICE...............134
FREEWHEELING CLUTCH
DESCRIPTION........................135
OPERATION..........................135
DISASSEMBLY........................136
ASSEMBLY...........................138
GEARSHIFT CABLE
DIAGNOSIS AND TESTING
GEARSHIFT CABLE..................138
REMOVAL............................139
INSTALLATION........................140
HOLDING CLUTCHES
DESCRIPTION........................141
OPERATION..........................142
HOLDING CLUTCH B1
DISASSEMBLY........................143
ASSEMBLY...........................145
HOLDING CLUTCH B2
DISASSEMBLY........................148
ASSEMBLY...........................150
INPUT SPEED SENSORS
DESCRIPTION........................153
OPERATION..........................154
OIL PUMP
DESCRIPTION........................154
OPERATION..........................154
DISASSEMBLY........................155
VATRANSMISSION 21 - 1
INSPECTION.........................155
ASSEMBLY...........................156
OUTPUT SHAFT BEARING
REMOVAL............................156
INSTALLATION........................158
OUTPUT SHAFT SEAL
REMOVAL............................159
INSTALLATION........................159
PARK LOCK CABLE
REMOVAL............................160
INSTALLATION........................161
PISTONS
DESCRIPTION........................163
OPERATION..........................163
PLANETARY GEARTRAIN
DESCRIPTION........................164
OPERATION..........................165
DISASSEMBLY........................166
ASSEMBLY...........................167
SHIFT MECHANISM
DESCRIPTION........................168
OPERATION..........................168REMOVAL............................169
INSTALLATION........................170
SOLENOID
DESCRIPTION........................171
OPERATION..........................174
TEMPERATURE SENSOR/PARK-NEUTRAL
CONTACT
DESCRIPTION
PARK/NEUTRAL CONTACT.............176
TRANSMISSION TEMPERATURE SENSOR . 176
OPERATION
PARK/NEUTRAL CONTACT.............177
TRANSMISSION TEMPERATURE SENSOR . 177
TORQUE CONVERTER
DESCRIPTION........................178
OPERATION..........................182
REMOVAL............................183
INSTALLATION........................184
TORQUE CONVERTER HUB SEAL
REMOVAL............................184
INSTALLATION........................184
21 - 2 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA
CONDITION POSSIBLE CAUSES CORRECTION
NO UPSHIFT OF 1ST
GEAR AT TIMES1. Connector Ballast Unit. Output
Speed Sensor Loose, Incorrectly
Contacted.1. Check Connectors, Replace
Output Speed sensor If Neces-
sary.
2. Output Speed Sensor Defective 2. Replace Output Speed Sen-
sor.
LEAKAGE AT THE AREA
OF THE ELECTRICAL
PLUG TO THE CONDUC-
TOR PLATE1. Deformation O-Rings. 1. Replace O-Rings.
2. Deformation Adapter. 2.Replace Adaptor.
3. The Conductor Plate Is Not Fitted
Surface To Surface On The Valve
Body In One Corner, The Plug Is
Not Centered In The Socket And
The O-ring Will Not Seal.3. Remove Nose Of Conductor
Plate.
4. Contacting At The Conductor
Plate Leaky. Oil In Harness, Some-
times In The Control Module.4. Replace Conductor Plate.
LEAKAGE AT THE AREA
OF BELL HOUSING/
TORQUE CONVERTER1. Bolts (Torx M6) Outer Disc Carri-
er B1.1. Clean Thread and Install the
Bolts Using Sealer.
OIL LEAKS 1. 6 Lower Bolts (TorxM8) Converter
Housing.1. Clean Thread and Install the
Bolts Using Sealer.
2. Oil Drain Plug Converter Loose
Resp. No Seal Ring Installed.2. Install Drain Plug Correctly.
3. Weld Seam Of Torque Converter
Leaky.3. Replace Torque Converter.
4. Radial Sealing Ring Oil Pump
Defective.4. Replace Sealing Ring.
5. O-Ring Oil Pump Defective Or
Not Installed.5. Install O-Ring.
6. Bushing Of Oil Pump Loose,
caused By Missing Fit Bolt At
Transmission/Engine Flange.6. Install Fit Bolt If Necessary.
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR
Damaged or worn threads in the aluminum trans-
mission case and valve body can be repaired by the
use of Heli-CoilsŸ, or equivalent. This repair con-
sists of drilling out the worn-out damaged threads.
Then tap the hole with a special Heli-CoilŸ tap, or
equivalent, and installing a Heli-CoilŸ insert, or
equivalent, into the hole. This brings the hole back to
its original thread size.
Heli-CoilŸ, or equivalent, tools and inserts are
readily available from most automotive parts suppli-
ers.
REMOVAL
(1) Disconnect the negative (ground) battery cable.
CAUTION: Isolate ground lead to prevent accidental
contact.(2) Apply parking brake.
(3) Move gear selector lever to position ªNº.
(4) Remove oil drain plug (2) (Fig. 26) and drain
automatic transmission oil into a clean container.
21 - 42 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA
(0.114 in.), 3.2 mm (0.126 in.), and 3.5 mm (0.138
in.).
ELECTROHYDRAULIC UNIT
DESCRIPTION
The electrohydraulic control unit (Fig. 99) com-
prises the shift plate (13) made from light alloy for
the hydraulic control and an electrical control unit
(12). The electrical control unit (12) comprises of a
supporting body made of plastic, into which the elec-
trical components (1 - 11) are assembled. The sup-
porting body is mounted on the shift plate (13) and
screwed to it.
Strip conductors inserted into the supporting body
make the connection between the electrical compo-
nents and a plug connector. The connection to the
wiring harness on the vehicle and the transmission
control module (TCM) is produced via this 13-pin
plug connector with a bayonet lock.
ELECTRICAL CONTROL UNIT
The electric valve control unit (7) (Fig. 100) con-
sists of a plastic shell which houses the RPM sensors
(1,12), regulating solenoid valves (3, 4), solenoid
valves (5, 6, 10), the TCC solenoid valve (11), the
park/neutral contact (9), and the transmission oil
temperature sensor (8). Conductor tracks integrated
into the shell connect the electric components to a
plug connection (2). This 13-pin plug connection (2)
establishes the connection to the vehicle-side cable
harness and to the transmission control module
(TCM). With the exception of the solenoid valves, all
other electric components are fixed to the conductor
tracks.
HYDRAULIC CONTROL UNIT
Working Pressure (Line Pressure or Operating Pressure)
(p-A)
The working pressure provides the pressure supply
to the hydraulic control and the transmission shift
elements. It is the highest hydraulic pressure in the
entire hydraulic system. The working pressure is reg-
ulated at the working pressure regulating valve in
Fig. 99 Electrical Unit Components
1 - SOLENOID CAP
2 - SOLENOID CAP
3 - BOLT - M6X32
4 - BOLT - M6X30
5 - LEAF SPRING
6 - MODULATING PRESSURE REGULATING SOLENOID VALVE
7 - SHIFT PRESSURE REGULATING SOLENOID
8 - 3-4 SHIFT SOLENOID
9 - TORQUE CONVERTER LOCK-UP SOLENOID
10 - 1-2/4-5 SHIFT SOLENOID
11 - 2-3 SHIFT SOLENOID
12 - ELECTRICHYDRAULIC CONTROL MODULE
13 - SHIFT PLATE
Fig. 100 Electrical Control Unit
1 - N3 SPEED SENSOR
2 - PLUG CONNECTOR
3 - MODULATING PRESSURE REGULATING SOLENOID
4 - SHIFT PRESSURE REGULATING SOLENOID
5 - 1-2/4-5 SHIFT SOLENOID
6 - 3-4 SHIFT SOLENOID
7 - ELECTRICAL CONTROL UNIT
8 - TRANSMISSION TEMPERATURE SENSOR
9 - STARTER INTERLOCK CONTACT
10 - 2-3 SHIFT SOLENOID
11 - TORQUE CONVERTER LOCK-UP SOLENOID
12 - N2 SPEED SENSOR
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 105
Regulating Valve Pressure Regulating Valve
The regulating valve pressure regulating valve (1)
(Fig. 109) is located in the valve housing of the elec-
trohydraulic control module. It regulates the regulat-
ing valve/control valve pressure (p-RV).
Shift Valve Pressure Regulating Valve
The shift valve pressure regulating valve (1) (Fig.
110) is located in the valve housing of the electrohy-
draulic control module. It regulates the shift valve
pressure (p-SV).OPERATION
ELECTRICAL CONTROL UNIT
Signals from the transmission control module
(TCM) are converted into hydraulic functions in the
electric valve control unit (7) (Fig. 111). The RPM
sensors (1, 12), starter interlock contact (9), and
transmission oil temperature sensor (8) of the electric
valve control unit (7) supply the TCM with input sig-
nals. The solenoid valves are controlled by the TCM
and trigger the hydraulic functions.
Fig. 109 Regulating Valve Pressure Regulating
Valve
1 - REGULATING VALVE PRESSURE REGULATING VALVE
Fig. 110 Shift Valve Pressure Regulating Valve
1 - SHIFT VALVE PRESSURE REGULATING VALVE
Fig. 111 Electrical Control Unit
1 - N3 SPEED SENSOR
2 - PLUG CONNECTOR
3 - MODULATING PRESSURE REGULATING SOLENOID
4 - SHIFT PRESSURE REGULATING SOLENOID
5 - 1-2/4-5 SHIFT SOLENOID
6 - 3-4 SHIFT SOLENOID
7 - ELECTRICAL CONTROL UNIT
8 - TRANSMISSION TEMPERATURE SENSOR
9 - STARTER INTERLOCK CONTACT
10 - 2-3 SHIFT SOLENOID
11 - TORQUE CONVERTER LOCK-UP SOLENOID
12 - N2 SPEED SENSOR
21 - 112 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA
(7) Detach oil pan (5) (Fig. 125).
(8) Remove oil filter (4).
(9) Unscrew Torx socket bolts (3) and remove elec-
trohydraulic control module (2).
DISASSEMBLY
(1) Remove electrohydraulic unit from the vehicle.
(Refer to 21 - TRANSMISSION/AUTOMATIC
TRANSMISSION - NAG1/ELECTROHYDRAULIC
UNIT - REMOVAL)
(2) Remove solenoid caps (1, 2) (Fig. 126).
(3) Unscrew Torxtsocket bolts (3, 4) (Fig. 126).
NOTE: Pay attention to the different lengths of the
TorxTsocket bolts.
(4) Remove leaf springs (5).
(5) Withdraw solenoid valves (6 - 11) from shift
plate (13).
NOTE: Check O-rings on solenoid valves for dam-
age and replace if necessary.
(6) Bend away retaining lug on stiffening rib on
transmission oil temperature sensor.
(7) Remove electrohydraulic control module (12)
from the shift plate (13).
Fig. 125 Remove Electrohydraulic Unit
1 - HEAT SHIELD
2 - ELECTROHYDRAULIC UNIT
3 - BOLT
4 - OIL FILTER
5 - OIL PAN
6 - CLAMPING ELEMENT
7 - BOLT
8 - DRAIN PLUG
9 - DRAIN PLUG GASKET
10 - 13-PIN PLUG CONNECTOR
11 - BOLT
12 - GUIDE BUSHINGFig. 126 Electrical Unit Components
1 - SOLENOID CAP
2 - SOLENOID CAP
3 - BOLT - M6X32
4 - BOLT - M6X30
5 - LEAF SPRING
6 - MODULATING PRESSURE REGULATING SOLENOID VALVE
7 - SHIFT PRESSURE REGULATING SOLENOID
8 - 3-4 SHIFT SOLENOID
9 - TORQUE CONVERTER LOCK-UP SOLENOID
10 - 1-2/4-5 SHIFT SOLENOID
11 - 2-3 SHIFT SOLENOID
12 - ELECTRICHYDRAULIC CONTROL MODULE
13 - SHIFT PLATE
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 121
(13) Install the electrohydraulic control module
(12) onto the shift plate (13) (Fig. 142).
(14) Bend the retaining lug on stiffening rib on
transmission oil temperature sensor to retain the
electrohydraulic control module.
(15) Install the solenoid valves (6 - 11) into shift
plate (13).
NOTE: Check O-rings on solenoid valves for dam-
age and replace if necessary.
(16) Install the leaf springs (5).
(17) Install the Torxtsocket bolts (3, 4) (Fig. 142).
Tighten the bolts to 8 N´m (71 in.lbs.).
NOTE: Pay attention to the different lengths of the
TorxTsocket bolts.
(18) Install the solenoid caps (1, 2).
(19) Install the electrohydraulic unit into the vehi-
cle.
INSTALLATION
(1) Position the electrohydraulic unit in the trans-
mission housing.
(2) Insert selector valve (1) (Fig. 143) in driver of
detent plate (2). When installing the electrohydraulic
control module in the transmission housing, the plas-
tic part of the selector valve (1) must engage in the
driver of the detent plate (2).Fig. 142 Electrical Unit Components
1 - SOLENOID CAP
2 - SOLENOID CAP
3 - BOLT - M6X32
4 - BOLT - M6X30
5 - LEAF SPRING
6 - MODULATING PRESSURE REGULATING SOLENOID VALVE
7 - SHIFT PRESSURE REGULATING SOLENOID
8 - 3-4 SHIFT SOLENOID
9 - TORQUE CONVERTER LOCK-UP SOLENOID
10 - 1-2/4-5 SHIFT SOLENOID
11 - 2-3 SHIFT SOLENOID
12 - ELECTRICHYDRAULIC CONTROL MODULE
13 - SHIFT PLATE
Fig. 143 Connect The Selector Valve To The Detent
Plate
1 - SELECTOR VALVE
2 - DETENT PLATE
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 129