Subaru Impreza 2004 User manual

FUJI HEAVY INDUSTRIES LTD. G1870GE4
2004 IMPREZA SERVICE MANUAL QUICK REFERENCE INDEX
TRANSMISSION SECTION
This service manual has been prepared
to provide SUBARU service personnel
with the necessary information and data
for the correct maintenance and repair
of SUBARU vehicles.
This manual includes the procedures
for maintenance, disassembling, reas-
sembling, inspection and adjustment of
components and diagnostics for guid-
ance of experienced mechanics.
Please peruse and utilize this manual
fully to ensure complete repair work for
satisfying our customers by keeping
their vehicle in optimum condition.
When replacement of parts during
repair work is needed, be sure to use
SUBARU genuine parts.
All information, illustration and specifi-
cations contained in this manual are
based on the latest product information
available at the time of publication
approval.
CONTROL SYSTEMS CS
AUTOMATIC TRANSMISSION 4AT
AUTOMATIC TRANSMISSION
(DIAGNOSTICS) 4AT(diag)
MANUAL TRANSMISSION AND
DIFFERENTIAL 5MT
MANUAL TRANSMISSION AND
DIFFERENTIAL 6MT
MANUAL TRANSMISSION AND
DIFFERENTIAL (DIAGNOSTICS) 6MT(diag)
CLUTCH SYSTEM CL

AUTOMATIC TRANSMISSION
4AT
Page
1. General Description ....................................................................................2
2. Automatic Transmission Fluid ...................................................................31
3. Differential Gear Oil...................................................................................33
4. Road Test..................................................................................................34
5. Stall Test ...................................................................................................35
6. Time Lag Test ...........................................................................................37
7. Line Pressure Test ....................................................................................38
8. Transfer Clutch Pressure Test ..................................................................39
9. Automatic Transmission Assembly ...........................................................41
10. Transmission Mounting System ................................................................48
11. Extension Case Oil Seal ...........................................................................50
12. Differential Side Retainer Oil Seal.............................................................51
13. Inhibitor Switch..........................................................................................52
14. Front Vehicle Speed Sensor .....................................................................56
15. Rear Vehicle Speed Sensor......................................................................60
16. Torque Converter Turbine Speed Sensor .................................................61
17. Control Valve Body ...................................................................................62
18. Shift Solenoids, Duty Solenoids and ATF Temperature Sensor ...............68
19. Transfer Duty Solenoid and Valve Body ...................................................70
20. ATF Filter ..................................................................................................73
21. Transmission Control Module (TCM) ........................................................74
22. ATF Cooler Pipe and Hose .......................................................................75
23. Air Breather Hose......................................................................................77
24. Oil Charge Pipe.........................................................................................78
25. Torque Converter Clutch Assembly ..........................................................79
26. Transmission Cover ..................................................................................80
27. Extension Case .........................................................................................81
28. Transfer Clutch..........................................................................................85
29. Multi-plate Clutch ......................................................................................91
30. Rear Drive Shaft........................................................................................92
31. Reduction Driven Gear..............................................................................93
32. Reduction Drive Gear................................................................................95
33. Center Differential Carrier .........................................................................97
34. Parking Pawl .............................................................................................99
35. Converter Case .......................................................................................100
36. Oil Pump Housing ...................................................................................102
37. Drive Pinion Shaft ...................................................................................108
38. Front Differential......................................................................................114
39. AT Transmission Main Case ...................................................................120
40. Transmission Control Device ..................................................................139

4AT-2
AUTOMATIC TRANSMISSION
General Description
1. General Description
A: SPECIFICATIONS
1. TORQUE CONVERTER CLUTCH
2. OIL PUMP
3. TRANSMISSION CONTROL ELEMENT
4. TRANSMISSION GEAR RATIO
5. PLANETARY GEAR AND PLATE
Model 1.6 L
2.0 L
Non-
turbo
2.5 L 2.0 L
Turbo
Type Symmetric, 3 element, single stage,
2 phase torque converter
Stall torque
ratio 2.2 —2.4 2.0 —2.2 1.85 — 2.15
2.05 —
2.35
Nominal
diameter 236 mm (9.29 in) 246 mm (9.69 in)
Stall speed
(at sea level)
2,400 —
3,000
rpm
2,200 —
2,700
rpm
2,100 —
2,600
rpm
2,900 —
3,500
rpm
One-way
clutch Sprague type one-way clutch
Type Pracoid constant-displacement pump
Driving method Driven by engine
Number of teeth Inner rotor 9
Outer rotor 10
Type 4-forward, 1-reverse,
double-row planetary gears
Multi-plate clutch 3 sets
Multi-plate brake 2 sets
One-way clutch
(sprague type) 1 sets
Gear ratio
1st 2.785
2nd 1.545
3rd 1.000
4th 0.694
Rev 2.272
Model 1.6 L
2.0 L
Non-
turbo
2.5 L 2.0 L
Turbo
Tooth num-
ber of front
sun gear
33
Tooth num-
ber of front
pinion
21
Tooth num-
ber of front
internal gear
75
Tooth num-
ber of rear
sun gear
42
Tooth num-
ber of rear
pinion
17
Tooth num-
ber of rear
internal gear
75
Drive &
driven plate
number of
high clutch
345
Drive &
driven plate
number of
low clutch
467
Drive &
driven plate
number of
reverse
clutch
12
Drive &
driven plate
number of 2-
4 brake
234
Drive &
driven plate
number of
low &
reverse
brake
467

4AT-3
AUTOMATIC TRANSMISSION
General Description
6. SELECTOR POSITION
7. HYDRAULIC CONTROL AND LUBRICA-
TION
8. COOLING AND HARNESS
9. TRANSFER
P (Park) Transmission in neutral, output member immov-
able, and engine start possible
R
(Reverse) Transmission in reverse for backing
N (Neu-
tral)
Transmission in neutral and engine start possi-
ble
D (Drive) 4-forward, Automatic gear change 1st ←→2nd
←→3rd ←→4th
3 (3rd) 3-forward, Automatic gear change 1st ←→2nd
←→3rd ←4th
2 (2nd) 2-forward, Automatic gear change 1st ←→2nd
←3rd ←4th
1 (1st) 1st gear locked (Deceleration possible 1st ←
2nd ←3rd ←4th)
Control
method Wire cable
Type
Electro-hydraulic control
[Four forward speed
changes by electrical signals
of vehicle speed and accel-
erator (throttle) opening]
Fluid Dexron III type
Fluid capac-
ity
1.6 L FWD
model
8.0 —8.3 2(8.5 —8.8 US
qt, 7.0 —7.3 Imp qt)
1.6 L AWD
and 2.0 L
Non-turbo
model
8.4 —8.7 2(8.9 —9.2 US
qt, 7.4 —7.7 Imp qt)
2.5 L and
2.0 L Turbo
model
9.3 —9.6 2(9.8 —10.1 US
qt, 8.2 —8.4 Imp qt)
Lubrication system Forced feed lubrication with
oil pump
Oil Automatic transmission fluid
(above mentioned)
Cooling system Liquid-cooled cooler incorpo-
rated in radiator
Inhibitor switch 12 poles
Transmission harness 20 poles
Model
1.6 L and
2.0 L Non-
turbo
2.5 L 2.0 L Turbo
Transfer
type Multi-plate transfer (MPT)
Variable
torque distri-
bution (VTD)
Drive &
driven plate
number of
transfer
clutch
453
Control
method Electro-hydraulic type
Lubricant The same Automatic transmission fluid used
in automatic transmission
Reduction
gear ratio 1.000 (53/53)

4AT-4
AUTOMATIC TRANSMISSION
General Description
10.FINAL REDUCTION
11.RECOMMENDED GEAR OIL
Model Except for 1.6 L, 2.0 L Turbo 1.6 L, 2.0 L Turbo
Front final gear ratio 4.111 (37/9) 4.444 (40/9)
Lubrication oil
(1) Item (3) API classification
(2) Front differential gear oil (4) SAE viscosity No. and appli-
cable temperature
Front differential oil capacity 1.1 —1.3 2(1.2 —1.4 US qt, 1.0 —1.1 Imp qt)
MT-00001
(1)
(4)
GL-5
(3)
(2)
( C)
( F)
-30 -26 -15 15
90
85W
80W
75W -90
25 30-5 0
-22 -15 23 32 8659 775

4AT-5
AUTOMATIC TRANSMISSION
General Description
B: COMPONENT
1. TORQUE CONVERTER CLUTCH AND CASE
(1) Pitching stopper bracket (Turbo
model)
(8) Oil drain pipe (16) Converter case
(9) Input shaft (17) Pitching stopper bracket (Non-
turbo model)(2) O-ring (10) O-ring
(3) Differential oil level gauge (11) Torque converter clutch ASSY
(4) Stay (12) Drain plug Tightening torque: N·m (kgf-m, ft-lb)
(5) Seal pipe (13) Gasket T1: 18 (1.8, 13.0)
(6) Oil pump shaft (14) Oil seal T2: 41 (4.2, 30.4)
(7) Clip (15) Clip (Turbo model) T3: 70 (7.1, 51.6)
AT-02375
T3
T3
T2
T2
T3
T1
(8)
(11)
(1) (2)
(3) (4)
(7)
(5)
(6)
(10)
(9)
(14)
(16)
(12)
(13)
(15)
(17)

4AT-6
AUTOMATIC TRANSMISSION
General Description
2. OIL PUMP
(1) Oil pump rotor (11) Gasket (21) Lock nut
(2) Oil pump cover (12) O-ring
(3) Seal ring (13) Test plug Tightening torque: N·m (kgf-m, ft-lb)
(4) Thrust needle bearing (14) Stud bolt T1: 7 (0.7, 5.1)
(5) Drive pinion shaft (15) O-ring T2: 13 (1.3, 9.4)
(6) Roller bearing (16) O-ring T3: 18 (1.8, 13.0)
(7) Shim (17) Oil seal retainer T4: 25 (2.5, 18.1)
(8) Oil pump housing (18) Oil seal T5: 40 (4.1, 30)
(9) Nipple (19) O-ring T6: 42 (4.3, 31)
(10) Air breather hose (20) Drive pinion collar T7: 116 (11.8, 85)
AT-00003

4AT-7
AUTOMATIC TRANSMISSION
General Description
3. TRANSMISSION CASE AND CONTROL DEVICE
AT-00854
(1)
(2)
(3)
(4)
(5) (6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)
(24)
(23)
(25)
(26)
(27)
(28)
(29)
(30) (32)
(34)
(33)
(31)
(36)
(37)
(35)
(39)
(40)
(42)
(41)
(38)
(43)
T4
T9
T5
T1
T10
T4
T9
T6
T7
T9
T2
T9
T8
T8
T3
T3
T9

4AT-8
AUTOMATIC TRANSMISSION
General Description
(1) ATF level gauge (20) Oil filter stud bolt (39) Nipple
(2) Oil charge pipe (21) Drain plug (40) Air breather hose
(3) O-ring (22) Gasket (41) Transmission case
(4) Transfer valve plate (23) Oil pan (42) Plate ASSY
(5) Transfer valve ASSY (24) Magnet (43) Washer
(6) Transfer clutch seal (25) Stud bolt (Short)
(7) Transfer duty solenoid (26) Stud bolt (Long) Tightening torque: N·m (kgf-m, ft-lb)
(8) Straight pin (27) Parking rod T1: 3.5 (0.36, 2.6)
(9) Return spring (28) Manual plate T2: 5 (0.5, 3.6)
(10) Shaft (29) Spring pin T3: 6 (0.6, 4)
(11) Parking pawl (30) Detention spring T4: 8 (0.8, 6)
(12) Parking support (31) Ball T5: 12 (1.2, 8.7)
(13) Inlet filter (32) Spring T6: 13 (1.3, 10)
(14) Gasket (33) Gasket T7: 14 (1.4, 10)
(15) Inlet pipe (34) Outlet pipe T8: 18 (1.8, 13)
(16) Union screw (35) Union screw T9: 25 (2.6, 18)
(17) O-ring (36) Oil seal T10: 45 (4.6, 33)
(18) Test plug (37) Select lever
(19) Oil filter (Except for turbo model) (38) Inhibitor switch ASSY

4AT-9
AUTOMATIC TRANSMISSION
General Description
4. CONTROL VALVE AND HARNESS ROUTING
(1) Stay (12) Accumulator spring (24) Line pressure duty solenoid
(2) Transmission harness (13) Side plate (25) Low clutch timing solenoid
(3) O-ring (14) Separate plate (26) Lock-up duty solenoid
(4) O-ring (15) Middle valve body (27) Oil strainer
(5) Torque converter turbine speed
sensor
(16) Separate plate (28) SPORT shift solenoid
(if equipped)
(17) Fluid filter
(6) O-ring (18) Fluid filter
(7) Front vehicle speed sensor (19) Lower valve body Tightening torque: N·m (kgf-m, ft-lb)
(8) O-ring (20) Shift solenoid 2 T1: 7 (0.7, 5.1)
(9) Rear vehicle speed sensor (21) Shift solenoid 1 T2: 8 (0.8, 5.8)
(10) Upper valve body (22) 2-4 brake timing solenoid
(11) Accumulator piston (23) 2-4 brake duty solenoid
AT-01277
T1
T2
T2
T2
T2
T2
T2 T2
T2
T1
T1
(1)
(2)
(3)
(4)
(5)
(6) (7)
(8)
(9)
(10)
(11)
(12) (14)
(13) (15)
(16)
(17)
(24)
(19)
(18)
(20)
(21)
(22)
(28)
(23)
(26)
(25)
(27)

4AT-10
AUTOMATIC TRANSMISSION
General Description
5. HIGH CLUTCH AND REVERSE CLUTCH
(1) High clutch drum (8) Spring retainer (15) Dish plate
(2) Lip seal (9) Cover (16) Driven plate (Reverse clutch)
(3) D-ring (10) Snap ring (17) Drive plate (Reverse clutch)
(4) Reverse clutch piston (11) Driven plate (High clutch) (18) Retaining plate (Reverse clutch)
(5) D-ring (12) Drive plate (High clutch) (19) Snap ring
(6) D-ring (13) Retaining plate (High clutch) (20) Thrust needle bearing
(7) High clutch piston (14) Snap ring (21) High clutch hub
AT-00006

4AT-11
AUTOMATIC TRANSMISSION
General Description
6. PLANETARY GEAR AND 2-4 BRAKE
(1) Thrust needle bearing (10) Washer (19) Snap ring
(2) Front sun gear (11) Thrust needle bearing (20) Spring retainer
(3) Thrust needle bearing (12) Rear internal gear (21) 2-4 brake piston
(4) Snap ring (13) Washer (22) D-ring
(5) Front planetary carrier (14) Snap ring (23) D-ring
(6) Thrust needle bearing (15) Retaining plate (24) 2-4 brake piston retainer
(7) Rear sun gear (16) Drive plate (25) 2-4 brake seal
(8) Thrust needle bearing (17) Driven plate (26) Leaf spring
(9) Rear planetary carrier (18) Pressure rear plate
AT-00007
(1)
(2)
(3)
(4)
(5)
(6)
(14)
(15)
(16)
(16)
(16)
(18)
(17)
(20)
(26)
(17)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(19)
(21)
(22)
(23) (25)
(24)

4AT-12
AUTOMATIC TRANSMISSION
General Description
7. LOW CLUTCH AND LOW & REVERSE BRAKE
(1) Snap ring (12) Low clutch drum (23) Return spring
(2) Retaining plate (13) Needle bearing (24) Snap ring
(3) Drive plate (14) Snap ring (25) Retaining plate
(4) Driven plate (15) One-way clutch (26) Leaf spring
(5) Dish plate (16) Snap ring (27) Drive plate
(6) Snap ring (17) Thrust needle bearing (28) Driven plate
(7) Cover (18) Seal ring (29) Dish plate
(8) Spring retainer (19) Needle bearing (30) Low and reverse brake piston
(9) D-ring (20) One-way clutch inner race
(10) Low clutch piston (21) Socket bolt Tightening torque: N·m (kgf-m, ft-lb)
(11) D-ring (22) Spring retainer T: 25 (2.5, 18.1)
AT-01278
(2)
(3) (4)
(3)
(4)
(5) (6)
(7)
(8)
(9)
(10) (11)
(12)
(17)
(24) (26)
(25)
(27)
(28)
(27)
(28)
(29)
(30)
(18)
(19)
(20)
(23)
(21)
(22)
(13)
(14)
(15)
(16)
T
(1)

4AT-13
AUTOMATIC TRANSMISSION
General Description
8. REDUCTION GEAR WITH MPT
(A) AWD (B) FWD
(1) Seal ring (7) Ball bearing (13) Ball bearing
(2) Ball bearing (8) Snap ring
(3) Reduction drive gear (9) Reduction driven gear Tightening torque: N·m (kgf-m, ft-lb)
(4) Reduction drive shaft (10) Washer T: 100 (10.2, 73.8)
(5) Drive pinion shaft (11) Lock nut
(6) Snap ring (12) Reduction drive shaft
AT-02376
(A)
(2)
(3)
(4)
(1)
(5)
(7)
(8)
(9)
(10)
T
(11)
(8)
(8)
(6)
(1)
(B)
(2)
(3)
(5)
(12)
(13)
(7)
(8)
(9)
(8)
(8)
(6)
(10)
T
(11)

4AT-14
AUTOMATIC TRANSMISSION
General Description
9. REDUCTION GEAR WITH VTD
(1) Ball bearing (13) Rear drive shaft (25) Snap ring
(2) Reduction drive gear (14) Ball bearing (26) Ball bearing
(3) Washer (15) Multi-plate clutch (LSD) hub (27) Snap ring
(4) Needle bearing (16) Ball bearing (28) Reduction driven gear
(5) Pinion gear (17) Revolution gear (29) Lock washer
(6) Carrier (18) Driven plate (Thick) (30) Lock nut
(7) Planetary pinion shaft (19) Driven plate (31) Gasket
(8) Snap ring (20) Driven plate (Thin) (32) Extension case
(9) Seal ring (21) Driven plate (Thick)
(10) Thrust needle bearing (22) Pressure plate Tightening torque: N·m (kgf-m, ft-lb)
(11) Intermediate shaft (23) Rear drive shaft shim T: 100 (10.2, 73.8)
(12) Thrust washer (24) Drive pinion shaft
AT-02203
T
(3)
(4)
(5)
(4) (3) (2)
(1)
(6)
(7)
(8)
(9)
(10)
(11)
(17) (18)
(19)
(20)
(19)
(21)
(22)
(23)
(32)
(31)
(30)
(12)
(13)
(14) (15)
(16)
(29)
(28)
(26)
(25)
(24)
(27)
(27)
(27)

4AT-15
AUTOMATIC TRANSMISSION
General Description
10.DIFFERENTIAL GEAR
(1) Crown gear (7) Oil seal (13) Differential bevel gear
(2) Pinion shaft (8) O-ring
(3) Differential case (RH) (9) Differential side retainer Tightening torque: N·m (kgf-m, ft-lb)
(4) Straight pin (10) Lock plate T1: 25 (2.5, 18.1)
(5) Differential case (LH) (11) Washer T2: 62 (6.3, 45.6)
(6) Taper roller bearing (12) Differential bevel pinion
AT-00011
T2
T1
T1
(8)
(8)
(9)
(9) (7)
(7)
(6)
(6)
(10)
(13)
(13)
(1)
(2)
(3)
(4)
(5)
(10)
(11)
(11) (12)
(12)

4AT-16
AUTOMATIC TRANSMISSION
General Description
11.TRANSFER AND EXTENSION CASE WITH MPT
(1) Thrust needle bearing (10) Return spring (19) Oil seal
(2) Needle bearing (11) Transfer clutch piston (20) Dust cover
(3) Snap ring (12) Rear drive shaft (21) Test plug
(4) Pressure plate (13) Ball bearing (22) O-ring
(5) Drive plate (14) Seal ring (23) Clip
(6) Driven plate (15) Gasket
(7) Retaining plate (16) Transfer clutch pipe Tightening torque: N·m (kgf-m, ft-lb)
(8) Snap ring (17) Extension case T1: 13 (1.3, 9.4)
(9) Transfer piston seal (18) Transmission hanger T2: 25 (2.5, 18.1)
AT-00012
(1) (2)
(3)
(4)
(5)
(6)
(7)
(8) (9)
(10)
(11)
(16)
(23)
(18)
(19)
(22)
(21)
(12)
(13)
(14)
(15)
(5)
(17)
(20)
T2
T2
T1
(6)

4AT-17
AUTOMATIC TRANSMISSION
General Description
12.TRANSFER AND EXTENSION CASE WITH VTD
(1) Driven plate (Thick) (10) Multi-plate clutch (LSD) piston (19) O-ring
(2) Driven plate (11) D-ring (20) Rear wheel sensor
(3) Driven plate (Thin) (12) Gasket (21) Transmission hanger
(4) Driven plate (Thick) (13) Multi-plate clutch (LSD) pipe (22) Harness bracket
(5) Retaining plate (14) Extension case
(6) Snap ring (15) O-ring Tightening torque: N·m (kgf-m, ft-lb)
(7) Spring retainer (16) Test plug T1: 7 (0.7, 5.1)
(8) Plate (17) Oil seal T2: 13 (1.3, 9.4)
(9) O-ring (18) Dust cover T3: 25 (2.5, 18.1)
AT-02377
(1) (2)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
T2
T1
T3
(15)
(16)
(17)
(18)
(19)
(20)
(22)
(21)

4AT-18
AUTOMATIC TRANSMISSION
General Description
13.TRANSMISSION MOUNTING
(1) Pitching stopper (4) Rear cushion rubber (AWD model) Tightening torque: N·m (kgf-m, ft-lb)
(2) Rear bracket (FWD model) (5) Crossmember T1: 35 (3.6, 26)
(3) Rear cushion rubber (FWD model) (6) Stopper T2: 39 (4.0, 29)
T3: 50 (5.1, 37)
T4: 58 (5.9, 43)
T5: 70 (7.1, 51)
T6: 123 (12.5, 90)
AT-01276
(1)
(2)
(3)
(4)
(5)
(6)
T4
T3
T5
T5
T2
T2
T1
T6
T1

4AT-19
AUTOMATIC TRANSMISSION
General Description
C: CAUTION
•Wear working clothing, including a cap, protec-
tive goggles and protective shoes during operation.
•Remove contamination including dirt and corro-
sion before removal, installation, and disassembly.
•Keep the disassembled parts in order and pro-
tect them from dust or dirt.
•Until the oil pan is removed, do not place with the
oil pan inner side facing up to prevent foreign mat-
ter from entering the valve body.
•Before removal, installation or disassembly, be
sure to clarify the failure. Avoid unnecessary re-
moval, installation, disassembly and replacement.
•When disassembling the case and other light al-
loy parts, use a plastic hammer to open. Do not pry
it apart with a screwdriver or other tool.
•Be careful not to burn your hands, because each
part on the vehicle is hot after running.
•Do not mix gear oil, grease etc. with that of an-
other grade or from other manufacturers.
•Be sure to tighten fasteners including bolts and
nuts to the specified torque.
•Place shop jacks or rigid racks at the specified
points.
•Apply ATF or gear oil onto sliding or revolution
surfaces before installation.
•Replace deformed or otherwise damaged snap
rings with new ones.
•Before installing O-rings or oil seals, apply suffi-
cient amount of ATF to avoid damage and defor-
mation.
•Be careful not to incorrectly install or fail to install
O-rings, snap rings and other such parts.
•Before securing a part on a vise, place cushion-
ing material such as wood blocks, aluminum plate,
or shop cloth between the part and the vise.
•Avoid damaging the mating surface of the case.
•Before applying sealant, completely remove the
old seal.
D: PREPARATION TOOL
1. SPECIAL TOOLS
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
498575400 OIL PRESSURE
GAUGE ASSY
Used for measuring oil pressure.
498897200 ADAPTER Used oil pump housing when measuring reverse
clutch pressure and line pressure.
ST-498575400
ST-498897200