diff SUBARU LEGACY 1999 Service Repair Manual

16) Remove front oil seal from differential carrier
using ST.
ST 398527700 PULLER ASSY
G3M0076
17) Remove pilot bearing together with front bear-
ing cone using ST.
ST 398467700 DRIFT
B3M0872A
18) When replacing bearings, tap front bearing
cup and rear bearing cup in this order out of case
by using a brass bar.
G3M0078
2. VA-TYPE
To detect real cause of trouble, inspect the follow-
ing items before disassembling.
ITooth contact of crown gear and pinion, and
backlash
IRunout of crown gear at its back surface
ITurning resistance of drive pinion1) Set ST on vise and install the differential
assembly to ST.
ST 398217700 ATTACHMENT
G3M0060
2) Drain gear oil by removing plug.
3) Remove rear cover by loosening retaining
bolts.
G3M0061
4) Replace air breather cap.
NOTE:
Do not attempt to replace the air breather cap
unless necessary.
G3M0062
27
[W2C2]3-4SERVICE PROCEDURE
2. Rear Differential

5) Remove right and left lock plates.
G3M0063
6) Remove right and left holders with ST.
ST 399780111 WRENCH
G3M0064
7) Pull out differential assembly from differential
carrier.
CAUTION:
Be careful not to hit the teeth against the case.
G3M0065
8) Remove bearing race from right and left holders
with ST1 and ST2.
ST1 499705401 BEARING OUTER RACE
PULLER ASSY
ST2 499705404 OUTER RACE PULLER
SEAT
G3M0066
9) Remove oil seal from right and left holders with
screwdriver.
CAUTION:
Perform this operation only when changing oil
seal.
B3M0132
28
3-4[W2C2]SERVICE PROCEDURE
2. Rear Differential

10) Extract bearing cone with ST.
CAUTION:
Do not attempt to disassemble the parts unless
necessary.
NOTE:
ISet Puller so that its claws catch the edge of the
bearing cone.
INever mix up the right and left hand bearing
cones.
ST 899524100 PULLER SET
G3M0068
11) Remove crown gear by loosening crown gear
bolts.
G3M0069
12) Drive out pinion shaft lock pin from crown gear
side.
NOTE:
The lock pin is staked at the pin hole end on the
differential case; do not drive it out forcibly before
unstaking it.
ST 899904100 STRAIGHT PIN REMOVER
B3M0133
13) Draw out pinion mate shaft and remove pinion
mate gears, side gears and thrust washers.
NOTE:
The gears as well as thrust washers should be
marked or kept separated left and right, and front
and rear.
G3M0071
14) Hold companion flange with ST and remove
drive pinion nut.
ST 498427200 FLANGE WRENCH
G3M0072
15) Extract the companion flange with a puller.
G3M0073
29
[W2C2]3-4SERVICE PROCEDURE
2. Rear Differential

16) Press the end of drive pinion shaft and extract
it together with rear bearing cone, preload adjust-
ing spacer and washer.
NOTE:
Hold the drive pinion so as not to drop it.
ST 398467700 DRIFT
G3M0074
17) Remove rear bearing cone from drive pinion
by supporting cone with ST.
NOTE:
Place the replacer so that its center-recessed side
faces the pinion gear.
ST 498515500 REPLACER
G3M0075
18) Remove front oil seal from differential carrier.
ST 499705401 PULLER ASSY
G3M0076
19) Remove pilot bearing together with front bear-
ing cone using ST.
ST 398467700 DRIFT
B3M0872A
20) When replacing bearings, tap front bearing
race and rear bearing race in this order out of case
by using a brass bar.
G3M0078
D: INSPECTION
Wash all the disassembled parts clean, and exam-
ine them for wear, damage, or other defects.
Repair or replace defective parts as necessary.
1) Crown gear and drive pinion
IIf abnormal tooth contact is evident, find out the
cause and adjust to give correct tooth contact at
assembly. Replace the gear if excessively worn or
incapable of adjustment.
IIf crack, score, or seizure is evident, replace as
a set. Slight damage of tooth can be corrected by
oil stone or the like.
2) Side gear and pinion mate gear
IReplace if crack, score, or other defects are evi-
dent on tooth surface.
IReplace if thrust washer contacting surface is
worn or seized. Slight damage of the surface can
be corrected by oil stone or the like.
3) Bearing
Replace if seizure, peeling, wear, rust, dragging
during rotation, abnormal noise or other defect is
evident.
4) Thrust washers of side gear and pinion mate
gear Replace if seizure, flaw, abnormal wear or
other defect is evident.
5) Oil seal
30
3-4[W2D0]SERVICE PROCEDURE
2. Rear Differential

Replace if deformed or damaged, and at every
disassembling.
6) Differential carrier
Replace if the bearing bores are worn or damaged.
7) Differential case
Replace if its sliding surfaces are worn or cracked.
8) Companion flange
Replace if the oil seal lip contacting surfaces have
flaws.
E: ASSEMBLY
1. T-TYPE
1) Precautions for assembling
IAssemble in the reverse order of disassembling.
ICheck and adjust each part during assembly.
IKeep the shims and washers in order, so that
they are not misinstalled.
IThoroughly clean the surfaces on which the
shims, washers and bearings are to be installed.
IApply gear oil when installing the bearings and
thrust washers.
IBe careful not to mix up the right and left hand
races of the bearings.
IReplace the oil seal with new one at every dis-
assembly. Apply chassis grease between the lips
when installing the oil seal.
G3M0079
2) Adjusting preload for front and rear bearings
Adjust the bearing preload with spacer and washer
between front and rear bearings. Pinion height
adjusting washers are not affected by this adjust-
ment. The adjustment must be carried out without
the oil seal inserted.
(1) Press rear bearing race into differential car-
rier with ST1 and ST2.
ST1 398477701 HANDLE
ST2 398427703 DRIFT 2
G3M1037
(2) Insert ST1 into carrier with pinion height
adjusting washer and rear bearing cone fitted
onto it.
CAUTION:
IRe-use the used washer if not deformed.
IUse a new rear bearing cone.
(3) Then install preload adjusting spacer and
washer, front bearing cone, ST2, companion
flange, and washer and drive pinion nut.
ST1 398507702 DUMMY SHAFT
ST2 398507703 DUMMY COLLAR
G3M0081
31
[W2E1]3-4SERVICE PROCEDURE
2. Rear Differential

(4) Turn ST1 with hand to make it seated, and
tighten drive pinion nut while measuring the pre-
load with spring balance. Select preload adjust-
ing washer and spacer so that the specified pre-
load is obtained when nut is tightened to the
specified torque with ST2.
ST1 398507704 BLOCK
ST2 398507702 DUMMY SHAFT
CAUTION:
Use a new lock nut.
NOTE:
IBe careful not to give excessive preload.
IWhen tightening the drive pinion nut, lock ST1
with ST2 as shown in the figure.
Tightening torque:
181
±15 N´m (18.5±1.5 kg-m, 134±11 ft-lb)
G3M1038
Front and rear bearing preload
For new bearing:
17.7 Ð 25.5 N (1.8 Ð 2.6 kg, 4.0 Ð 5.7 lb)
at companion flange bolt hole
G3M0082
Preload adjusting
washerPart No. Thickness 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)
Preload adjusting
spacerPart 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)
3) Adjusting drive pinion height
Adjust drive pinion height with shim installed
between rear bearing cone and the back of pinion
gear.
32
3-4[W2E1]SERVICE PROCEDURE
2. Rear Differential

(1) Install ST1, ST2 and ST3, as shown in the
figure, and apply the specified preload on the
bearings.
Front and rear bearing preload
For new bearing:
17.7 Ð 25.5 N (1.8 Ð 2.6 kg, 4.0 Ð 5.7 lb)
at companion flange bolt hole
Adjust preload for front and rear bearings.
NOTE:
At this time, install a pinion height adjusting shim
which is temporarily selected or the same as that
used before.
ST1 398507702 DUMMY SHAFT
ST2 398507703 DUMMY COLLAR
ST3 398507701 DIFFERENTIAL CARRIER
GAUGE
G3M0083
(2) Measure the clearance ªNº between the end
of ST3 and the end surface of ST1 by using a
thickness gauge.
NOTE:
Make sure there is no clearance between the car-
rier and ST3.
ST1 398507702 DUMMY SHAFT
ST2 398507703 DUMMY COLLAR
ST3 398507701 DIFFERENTIAL CARRIER
GAUGE
G3M0263
(3) Obtain the thickness of pinion height adjust-
ing shim to be inserted from the following
formula, and replace the temporarily installed
shim with this one.
T=To+Nþ(H´0.01) þ 0.20 (mm)Where:
T = Thickness of pinion height adjusting shim
(mm)
To = Thickness of shim temporarily inserted
(mm)
N = Reading of thickness gauge (mm)
H = Figure marked on drive pinion head
(Example of calculation)
To = 2.20 + 1.20 = 3.40 mm
N = 0.23 mmH=+1,
T = 3.40 + 0.23 þ 0.01 þ 0.20 = 3.42
Result: Thickness = 3.42 mm
Therefore use the shim 383605200.
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)
4) Install the selected pinion height adjusting shim
on drive pinion, and press the rear bearing cone
into position with ST.
ST 398177700 INSTALLER
G3M0084
33
[W2E1]3-4SERVICE PROCEDURE
2. Rear Differential

5) Insert drive pinion into differential carrier, install
the previously selected bearing preload adjusting
spacer and washer.
B3M0560B
(A) Drive pinion
(B) Bearing preload adjusting spacer
(C) Washer
(D) Differential carrier
6) Press-fit front bearing cone into case with ST1,
ST2 and ST3.
ST1 398507703 DUMMY COLLAR
ST2 399780104 WEIGHT
ST3 899580100 INSTALLER
G3M0085
7) Insert spacer, then press-fit pilot bearing with
ST1 and ST2.
ST1 399780104 WEIGHT
ST2 899580100 INSTALLER
G3M0719
8) Fit a new oil seal with ST.
NOTE:
IPress-fit until end of oil seal is 1 mm (0.04 in)
inward from end of carrier.
IApply grease between the oil seal lips.
ST 498447120 OIL SEAL INSTALLER
G3M0087
9) Press-fit companion flange with ST1 and ST2.
CAUTION:
Be careful not to damage bearing.
ST1 899874100 INSTALLER
ST2 399780104 WEIGHT
G3M0720
10) Install self-locking nut. Then tighten it with ST.
ST 498427200 FLANGE WRENCH
Tightening torque:
181
±15 N´m (18.5±1.5 kg-m, 134±11 ft-lb)
G3M1052
11) Assembly of differential case
12) Install side gears and pinion mate gears, with
their thrust washers and pinion mate shaft, into
differential case.
34
3-4[W2E1]SERVICE PROCEDURE
2. Rear Differential

CAUTION:
IApply gear oil on both sides of the washer
and on the side gear shaft before installing.
IInsert the pinion mate shaft into the differen-
tial case by aligning the lock pin holes.
(1) Measure the clearance between differential
case and the back of side gear.
(2) Adjust the clearance as specified by select-
ing side gear thrust washer.
Side gear backlash:
0.1 Ð 0.2 mm (0.004 Ð 0.008 in)
Part No. Thickness mm (in)
3834452010.75 Ð 0.80
(0.0295 Ð 0.0315)
3834452020.80 Ð 0.85
(0.0315 Ð 0.0335)
3834452030.85 Ð 0.90
(0.0335 Ð 0.0354)
3834452040.90 Ð 0.95
(0.0354 Ð 0.0374)
3834452050.95 Ð 1.0
(0.0374 Ð 0.0394)
(3) Check the condition of rotation after apply-
ing oil to the gear tooth surfaces and thrust sur-
faces.
(4) After inserting pinion shaft lock pin into dif-
ferential case, stake the both sides of the hole
to prevent pin from falling off.
(5) Install crown gear on differential case.
CAUTION:
Before installing bolts, apply Lock Tite to bolt
threads.
Lock Tite:
THREE BOND 1324 or equivalent
NOTE:
Tighten diagonally while tapping the bolt heads.
Tightening torque:
103
±10 N´m (10.5±1.0 kg-m, 76±7 ft-lb)
G3M0069
13) Press side bearing cone onto differential case
with ST1.
ST1 398487700 DRIFT
G3M0091
14) Adjusting side bearing retainer shims
(1) The drive gear backlash and side bearing
preload can be determined by the side bearing
retainer shim thickness.
(2) Install the differential case assembly into
differential carrier in the reverse order of disas-
sembly.
G3M1035
(3) Install side retainer shims and O-rings to the
left and right retainers from which they were
removed.
NOTE:
IReplace broken or cracked O-ring with new one.
IReplace broken or corroded side retainer shim
with new one of same thickness.
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)
35
[W2E1]3-4SERVICE PROCEDURE
2. Rear Differential

(4) Align arrow marked on differential carrier
with that marked on side retainer during instal-
lation.
CAUTION:
Be careful that side bearing cup is not dam-
aged by bearing roller.
S3M0172A
(5) Tighten side bearing retainer bolts.
CAUTION:
Before tightening the two side bearing retainer
bolts, apply Lock Tite to bolt threads.
Lock Tite:
THREE BOND 1105 or equivalent
Tightening torque:
10.3
±1.5 N´m (1.05±0.15 kg-m, 7.6±1.1
ft-lb)
S3M0173
(6) Measure the crown gear-to-drive pinion
backlash.
Set magnet base on differential carrier. Align
contact point of dial gauge with tooth face of
crown gear, and move crown gear while holding
drive pinion still. Read value indicated on dial
gauge.
Backlash:
0.10 Ð 0.20 mm (0.0039 Ð 0.0079 in)
G3M1047
(7) At the same time, measure the turning
resistance of drive pinion. Compared with the
resistance when differential case is not
installed, if the increase of the resistance is not
within the specified range, readjust side bearing
retainer shims.
NOTE:
If measured backlash is not within specified range,
repeat procedure for adjustment of side bearing
retainer shims.
Turning resistance increase:
2.9 Ð 10.8 N (0.3 Ð 1.1 kg, 0.7 Ð 2.4 lb)
15) Re-check crown gear-to-pinion backlash.
Backlash:
0.10 Ð 0.20 mm (0.0039 Ð 0.0079 in)
G3M1047
36
3-4[W2E1]SERVICE PROCEDURE
2. Rear Differential