Subaru Impreza 2.5 L 2004 User manual

DIFFERENTIALS

DI-2
DIFFERENTIALS
GENERAL DESCRIPTION
1. General Description
A: SPECIFICATIONS
When replacing a rear differential assembly, select the correct one according to the following table.
NOTE:
Using the different rear differential assembly causes the drive line and tires to “drag”or emit abnormal noise
when AWD is selected.
•Identification •Rear differential gear oil
Recommended oil
CAUTION:
Each oil manufacturer has its base oil and addi-
tives. Thus, do not mix two or more brands.
MODEL
2.5 L 2.0 L Turbo
AT MT AT MT
Wagon Sedan Wagon Sedan
Rear differential type T-type model without LSD T-type model with LSD
LSD type —Viscous coupling
Identification EH EL EG EH EJ EF
Type of gear Hypoid gear
Gear ratio (Number of gear
teeth) 4.111 (37/9) 4.444 (37/9) 3.900 (39/10) 4.111 (37/9) 3.545 (39/11)
Oil capacity 0.8 2(0.8 US qt, 0.7 Imp qt)
Rear differential gear oil GL-5
MODEL 2.5 L Turbo STi
6MT
Rear differential type T-type model with LSD
LSD type Mechanical
Identification HK
Type of gear Hypoid gear
Gear ratio (Number of gear
teeth) 3.900 (39/10)
Oil capacity 0.9 —1.1 2(1.0 —1.2 US qt,
0.8 —1.0 Imp qt)
Rear differential gear oil GL-5 (For mechanical LSD)
DI-00001
(1) Item
(2) Differential gear oil
(3) API Classification
(4) SAE Viscosity NO. and Application Temperature
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

DI-3
DIFFERENTIALS
GENERAL DESCRIPTION
1. SERVICE DATA
2. ADJUSTING PARTS
•Except STi model
Front and rear bearing preload at companion flange bolt
hole N (kgf, lb)
Except STi
model 18.1 —38.8 (1.8 —4.0, 4.1 —8.7)
STi model 24.1 —38.6 (2.5 —3.9, 5.4 —8.7)
Side gear backlash mm (in) 0.10 —0.20 (0.0039 —0.0079)
Side bearing standard width mm (in) 20.00 (0.7874)
Crown gear to drive pinion backlash mm (in) 0.10 —0.20 (0.0039 —0.0079)
Crown gear runout on its back surface mm (in) Less than 0.05 (0.0020)
Front and rear bearing preload at com-
panion flange bolt hole N (kgf, lb) 18.1 —38.8 (1.8 —4.0, 4.1 —8.7)
Preload adjusting spacer
Part No. Length mm (in)
383695201 56.2 (2.213)
383695202 56.4 (2.220)
383695203 56.6 (2.228)
383695204 56.8 (2.236)
383695205 57.0 (2.244)
383695206 57.2 (2.252)
Preload adjusting washer
Part No. Length mm (in)
383705200 2.59 (0.1020)
383715200 2.57 (0.1012)
383725200 2.55 (0.1004)
383735200 2.53 (0.0996)
383745200 2.51 (0.0988)
383755200 2.49 (0.0980)
383765200 2.47 (0.0972)
383775200 2.45 (0.0965)
383785200 2.43 (0.0957)
383795200 2.41 (0.0949)
383805200 2.39 (0.0941)
383815200 2.37 (0.0933)
383825200 2.35 (0.0925)
383835200 2.33 (0.0917)
383845200 2.31 (0.0909)

DI-4
DIFFERENTIALS
GENERAL DESCRIPTION
•STi model
Pinion height adjusting shim
Part No. Thickness mm (in)
383495200 3.09 (0.1217)
383505200 3.12 (0.1228)
383515200 3.15 (0.1240)
383525200 3.18 (0.1252)
383535200 3.21 (0.1264)
383545200 3.24 (0.1276)
383555200 3.27 (0.1287)
383565200 3.30 (0.1299)
383575200 3.33 (0.1311)
383585200 3.36 (0.1323)
383595200 3.39 (0.1335)
383605200 3.42 (0.1346)
383615200 3.45 (0.1358)
383625200 3.48 (0.1370)
383635200 3.51 (0.1382)
383645200 3.54 (0.1394)
383655200 3.57 (0.1406)
383665200 3.60 (0.1417)
383675200 3.63 (0.1429)
383685200 3.66 (0.1441)
Side gear backlash mm (in) 0.1 —0.2 (0.0039 —0.0079)
Side gear thrust washer
(Model without LSD)
Part No. Thickness mm (in)
383445201 0.75 —0.80 (0.0295 —0.0315)
383445202 0.80 —0.85 (0.0315 —0.0335)
383445203 0.85 —0.90 (0.0335 —0.0354)
Side bearing standard width mm (in) —20.00 (0.7874)
Side bearing retainer shim
Part No. Thickness mm (in)
383475201 0.20 (0.0079)
383475202 0.25 (0.0098)
383475203 0.30 (0.0118)
383475204 0.40 (0.0157)
383475205 0.50 (0.0197)
Crown gear to drive pinion
backlash mm (in) Limit
0.10 —0.20 (0.0039 —0.0079)
Crown gear runout on its back
surface mm (in) 0.05 (0.0020)
Front and rear bearing preload at com-
panion flange bolt hole N (kgf, lb) 24.1 —38.6 (2.5 —3.9, 5.4 —8.7)
Preload adjusting spacer
Part No. Length mm (in)
31454AA130 52.2 (2.055)
31454AA140 52.4 (2.063)
31454AA150 52.6 (2.071)
31454AA160 52.8 (2.079)
31454AA170 53.0 (2.087)
31454AA180 53.2 (2.094)

DI-5
DIFFERENTIALS
GENERAL DESCRIPTION
Preload adjusting washer
Part No. Length mm (in)
383705200 2.59 (0.1020)
383715200 2.57 (0.1012)
383725200 2.55 (0.1004)
383735200 2.53 (0.0996)
383745200 2.51 (0.0988)
383755200 2.49 (0.0980)
383765200 2.47 (0.0972)
383775200 2.45 (0.0965)
383785200 2.43 (0.0957)
383795200 2.41 (0.0949)
383805200 2.39 (0.0941)
383815200 2.37 (0.0933)
383825200 2.35 (0.0925)
383835200 2.33 (0.0917)
383845200 2.31 (0.0909)
Pinion height adjusting shim
Part No. Length mm (in)
38336AA230 3.09 (0.1217)
38336AA240 3.12 (0.1228)
38336AA250 3.15 (0.1240)
38336AA260 3.18 (0.1252)
38336AA270 3.21 (0.1264)
38336AA280 3.24 (0.1276)
38336AA290 3.27 (0.1287)
38336AA300 3.30 (0.1299)
38336AA310 3.33 (0.1311)
38336AA320 3.36 (0.1323)
38336AA330 3.39 (0.1335)
38336AA340 3.42 (0.1346)
38336AA350 3.45 (0.1358)
38336AA360 3.48 (0.1370)
38336AA370 3.51 (0.1382)
38336AA380 3.54 (0.1394)
38336AA390 3.57 (0.1406)
38336AA400 3.60 (0.1417)
38336AA410 3.63 (0.1429)
38336AA420 3.66 (0.1441)
Side bearing standard width mm (in) 20.00 (0.7874)
Side bearing retainer shim
Part No. Thickness mm (in)
383475201 0.20 (0.0079)
383475202 0.25 (0.0098)
383475203 0.30 (0.0118)
383475204 0.40 (0.0157)
383475205 0.50 (0.0197)
Crown gear to drive pinion
backlash mm (in) Limit
0.10 —0.20 (0.0039 —0.0079)
Crown gear runout on its back
surface mm (in) 0.05 (0.0020)

DI-6
DIFFERENTIALS
GENERAL DESCRIPTION
B: COMPONENT
1. REAR DIFFERENTIAL WITHOUT LSD
(1) Pinion crown gear and drive pin-
ion set
(13) Side bearing (26) Stud bolt
(14) O-ring (27) Oil filler plug
(2) Pinion height adjusting shim (15) Side bearing retainer shim (28) Oil drain plug
(3) Rear bearing (16) Side bearing retainer (29) Rear cover
(4) Bearing preload adjusting spacer (17) Side oil seal (30) Differential case
(5) Bearing preload adjusting washer (18) Side gear thrust washer (31) Gasket
(6) Differential carrier (19) Side gear
(7) Front bearing (20) Pinion mate gear Tightening torque: N·m (kgf-m, ft-lb)
(8) Spacer (21) Pinion mate gear washer T1: 10.3 (1.05, 7.6)
(9) Pilot bearing (22) Pinion shaft lock pin T2: 29 (3.0, 21.7)
(10) Front oil seal (23) Circlip T3: 49 (5.0, 36.2)
(11) Companion flange (24) Pinion mate shaft T4: 105 (10.7, 77.4)
(12) Self-locking nut (25) Air breather cap T5: 181 (18.5, 134)
DI-00260
( 1 )
( 1 )
( 2 )
( 3 )
( 4 )
( 5 )
( 6 )
( 7 )
( 8 )
( 9 )
(10)
(11)
(12)
(13)
(13)
(14)
(14)
(15)
(15)
(16)
(16)
(17)
(17)
(18)
(18)
(19)
(19)
(20)
(20)
(23) (21)
(21)
(22)
(24)
(30) (23)
(25)
(26)
(27)
(28)
(29)
(31)
T1
T2
T3
T3
T4
T5
T1

DI-7
DIFFERENTIALS
GENERAL DESCRIPTION
2. REAR DIFFERENTIAL WITH LSD
(1) Pinion crown gear and drive pin-
ion set
(14) O-ring (25) Oil filler plug (Rear differential oil
temperature switch) (STi model)
(15) Side bearing retainer shim
(2) Pinion height adjusting shim (16) Side bearing retainer (26) Stay ground (STi model)
(3) Rear bearing (17) Side oil seal
(4) Bearing preload adjusting spacer (18) Gasket Tightening torque: N·m (kgf-m, ft-lb)
(5) Bearing preload adjusting washer (19) Differential case (Viscous cou-
pling type) (Except for STi model)
T1: 10.3 (1.05, 7.6)
(6) Differential carrier T2: 29 (3.0, 21.7) (Except for STi
model)
(7) Front bearing Differential case (Mechanical
type) (STi model)
(8) Collar 44 (4.5, 32.5) (STi model)
(9) Pilot bearing (20) Rear cover T3: 49 (5.0, 36.2)
(10) Front oil seal (21) Air breather cap T4: 105 (10.7, 77.4)
(11) Companion flange (22) Stud bolt T5: 181 (18.5, 134)
(12) Self-locking nut (23) Oil filler plug
(13) Side bearing (24) Oil drain plug
DI-00347
T4
T1
(18)
(14)
(5)
(4)
(1)
(19)
(6)
(13)
(16)
(3) (2)
(1)
(17)
(15)
T1
T5
(13)
(16)
(17)
(12) (11)
(10) (9)
(8)
(7)
(14) (15)
T2
T3
T3
(21)
(22)
(23)
(25)
(24)
(20)
(26)

DI-8
DIFFERENTIALS
GENERAL DESCRIPTION
3. REAR DIFFERENTIAL MOUNTING SYSTEM
(1) Differential front member (8) Differential mount bracket Tightening torque: N·m (kgf-m, ft-lb)
(2) Plate (9) Differential mount front cover T1: 20 (2.0, 14.5)
(3) Crossmember T2: 33 (3.4, 24.3)
(4) Differential rear member T3: 65 (6.6, 47.9)
(5) Differential mount lower bracket T4: 70 (7.1, 51.6)
(6) Stopper T5: 90 (9.2, 66.4)
(7) Dynamic damper T6: 100 (10.2, 73.8)
DI-00312
(1)
T5
(7)
(6)
T1
(8)
T2 T6
T5
(9) T1
T6 T2
(8)
(6)
T3
(7)
T5 (5)
(4)
T4
T4
(3)
(2)

DI-9
DIFFERENTIALS
GENERAL DESCRIPTION
C: CAUTION
•Wear working clothing, including a cap, protec-
tive goggles, and protective shoes during opera-
tion.
•Remove contamination including dirt and corro-
sion before removal, installation or disassembly.
•Keep the disassembled parts in order and pro-
tect them from dust or dirt.
•Before removal, installation or disassembly, be
sure to clarify the failure. Avoid unnecessary re-
moval, installation, disassembly, and replacement.
•Be careful not to burn your hands, because each
part on the vehicle is hot after running.
•Use SUBARU genuine gear oil, grease etc. or
the equivalent. Do not mix gear oil, grease etc. with
that of another grade or from other manufacturers.
•Be sure to tighten fasteners including bolts and
nuts to the specified torque.
•Place shop jacks or safety stands at the specified
points.
•Apply gear oil onto sliding or revolution surfaces
before installation.
•Before installing O-rings or snap rings, apply suf-
ficient amount of gear oil to avoid damage and de-
formation.
•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 face of the case.

DI-10
DIFFERENTIALS
GENERAL DESCRIPTION
D: PREPARATION TOOL
1. SPECIAL TOOLS
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
398477701 HANDLE Used for installing front and rear bearing cone.
398477702 DRIFT Used press-fitting the bearing cone of differential
carrier (rear).
398217700 ATTACHMENT SET Stand for rear differential carrier disassembly
and assembly.
498447120 INSTALLER Used for installing front oil seal.
ST-398477701
ST-398477702
ST-398217700
ST-498447120