differential LEXUS SC400 1991 Service Owner's Guide

DIFFERENTIAL CARRIER INSPECTION
SA0V3±05
1. CHECK RUNOUT OF DRIVE PINION SHAFTMeasure the runout of the drive pinion shaft at a position pin-
ion 10 mm (0.39 in.) from the end of the shaft.
Maximum runout:
0.08 mm (0.0031 in.)
If the runout is greater than the maximum, replace the drive
pinion and ring gear.
2. REMOVE DIFFERENTIAL CARRIER COVER
(a) Remove the 8 bolts from the carrier cover.
(b) Using a brass bar and hammer, separate the cover and carrier.
3. CHECK RING GEAR RUNOUT
Maximum runout: 0.05 mm (0.0020 in.)
If the runout is greater than the maximum, replace the drive
pinion, ring gear and differential case.
4. CHECK RING GEAR BACKLASH Measure the backlash of the ring gear at 3 points at least and
check that the average value is within the specification.
Backlash (average value):
0.08±0.13 mm (0.0031±0.0051 in.)
NOTICE: The difference between the maximum and minimum
measured values must be less than 0.05 mm (0.0020 in.).
SA±86±
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If the backlash is not within the specification, adjust the back-
lash. (See page SA±98)
5. MEASURE DRIVE PINION PRELOAD Using SST and a torque wrench, measure the drive pinion
preload using the backlash of the drive pinion and ring gear.
Preload (at start):
0.5±0.8 N Vm (5±8 kgf Vcm, 4.3±6.9 in. Vlbf)
HINT: With vehicles which have run less than 8,000 km
(5,000 miles), the preload may be large.
SST 09229±55010
Maximum preload (at start):
1.8 N Vm (18 kgf Vcm, 16.0 in. Vlbf)
6. CHECK TOTAL PRELOAD
Using SST and a torque wrench, measure the total preload.
SST 09229±55010
Total preload (at start):
In addition to drive pinion preload
0.5±0.8 N Vm (5±8 kgf Vcm, 4.3±6.9 in. Vlbf)
If necessary, disassemble and inspect the differential.
7. CHECK PINION GEAR BACKLASH Measure the pinion gear backlash while holding one side
gear toward the case.
Backlash:
0.05±0.02 mm (0.0020±0.0079 in.)
If the backlash is not within the specification, install the cor-
rect thrust washer. (See page SA±93)
8. CHECK TOOTH CONTACT PATTERN (See page SA±99)
DIFFERENTIAL CARRIER DISASSEMBLY
SA0V4±02
HINT: When fastening the differential carrier to an overhaul
stand, etc., fasten it at the 4 places on the ring gear side
shown in the illustration.
±
SUSPENSION AND AXLE REAR DIFFERENTIALSA±87
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1. REMOVE SIDE GEAR SHAFTUsing SST, remove the side gear shaft.
SST 09520±24010
NOTICE: Be careful not to damage the oil seal.
2. REMOVE SIDE GEAR SHAFT OIL SEALSUsing SST, remove the oil seals.
SST 09308±00010
3. REMOVE DIFFERENTIAL CARRIER RETAINER
(a) Remove the 8 bolts.
(b) Using SST, remove the carrier retainer. SST 09950±20017
4. REMOVE DIFFERENTIAL CASE Take the differential case out of the carrier while lifting the ring
gear side, as shown in the illustration.
SA±88
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5. REMOVE O±RING FROM DIFFERENTIAL CARRIERRETAINER
Using a screwdriver, remove the O±ring.
6. REMOVE SIDE BEARING OUTER RACE AND PLATE WASHER
Using SST and a press, press out the outer races and wash-
ers.
SST 09608±35014 (09608±06020, 09608±06110)
7. REMOVE DRIVE PINION, SPACER AND COMPANION FLANGE
(a) Using a hammer and chisel, loosen the staked part of the nut.
(b) Using SST, remove the nut. SST 09229±55010, 09330±00021
(c) Using a press, remove the drive pinion with the rear bearing and remove the companion flange.
NOTICE: Be careful not to drop the drive pinion.
±
SUSPENSION AND AXLE REAR DIFFERENTIALSA±89
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(d) Remove the spacer from the drive pinion.
8. REMOVE OIL SEALUsing SST, remove the oil seal.
SST 09308±00010
9. REMOVE OIL SLINGER AND FRONT BEARING
10. REMOVE REAR BEARING FROM DRIVE PINION Using SST and a press, remove the rear bearing from the
drive pinion.
SST 09950±00020
11. REMOVE FRONT AND REAR BEARING OUTER RACES AND ADJUSTING WASHER
NOTICE: Do not remove the outer race except when replacing
the bearings.
Using a brass bar and hammer, drive out the outer races and
adjusting washer from the differential carrier.
HINT: Measure the adjusting washer and note the thickness
for reassembly.
SA±90
±
SUSPENSION AND AXLE REAR DIFFERENTIAL
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12. REMOVE LH AND RH SNAP RING FROM SIDE GEARSHAFT
Using a screwdriver, remove the snap rings from the side
gear shaft.
13. REMOVE SIDE BEARINGS Using SST, r emove the side bearings LH and RH from the dif-
ferential case.
SST 09950±20017
14. REMOVE RING GEAR
(a) Place matchmarks on the ring gear and differential case.
(b) Remove the 10 ring gear set bolts.
(c) Using a plastic hammer, tap on the ring gear to separate it from the differential case.
15. DISASSEMBLE DIFFERENTIAL CASE
(a) Using a hammer and punch, drive out the straight pin.
±
SUSPENSION AND AXLE REAR DIFFERENTIALSA±91
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(b) Remove following parts from the differential case.wPinion shaft
w 2 differential pinions
w 2 pinion thrust washers
w 2 side gears
w 2 side gears thrust washers
DUST DEFLECTOR AND DUST COVER
REPLACEMENT
SA0V5±01
1. REPLACE COMPANION FLANGE DUST DEFLECTOR
(a) Using SST and a press, remove the dust deflector.
SST 09608±35014 (09608±06090), 09950±00020
(b) Using SST and a press, install a new dust deflector. SST 09316±60010 (09316±00010)
2. REPLACE SIDE GEAR SHAFT DUST COVER
(a) Using SST and a press, remove the dust cover. SST 09950±00020
(b) Using SST and a press, install a new dust cover. SST 09502±24010, 09608±35014 (09608±06020,09608±06120)
SA±92
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HINT: If the dust cover does not fit tightly against the flange
of the side gear shaft, use a screwdriver to drive it down tight.
DIFFERENTIAL CARRIER ASSEMBLY
SA0V6±04
1. ADJUST DIFFERENTIAL PINION GEAR BACKLASH
(a) Install the proper thrust washers on the side gears.HINT: Using the table below, select thrust washers which will
ensure that the backlash is within specification.
Thrust washer thickness:
 Thickness mm (in.) Thickness mm (in.) 

1.6 (0.063)1.8 (0.071)
 1.7 (0.067)±
(b) Install the side gears, pinion gears, pinion gear thrust
washers and pinion shaft in the differential case.
HINT: Align the holes of the dif ferential case and pinion shaft.
(c) Push the side gear shafts gently into the differential case by hand and install them.
(d) Measure the pinion gear backlash while holding one side gear toward the case.
Backlash:
0.05±0.20 mm (0.0020±0.0079 in.)
If the backlash is not within the specification, install the side
gear thrust washers with different thicknesses.
(e) Remove the side gear shaft.
2. INSTALL RING GEAR ON DIFFERENTIAL CASE
(a) Using a hammer and punch, install the straight pin through the differential case and hole of the pinion shaft.
±
SUSPENSION AND AXLE REAR DIFFERENTIALSA±93
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(b) Stake the differential case.
3. INSTALL RING GEAR ON DIFFERENTIAL CASE
(a) Clean the contact surfaces of the differential case and thethreads of the ring gear and differential case.
(b) Heat the ring gear in boiling water.
(c) A f t e r t h e m o i s t u r e o n t h e r i n g g e a r h a s c o m p l e t e l y evaporated, quickly install the ring gear to the differential
case.
HINT: Align the matchmarks on the ring gear and the dif feren-
tial case.
(d) Tighten 2 of the bolts temporarily so that the bolt holes in the ring gear and differential case are not misaligned.
NOTICE: The ring gear set bolts should not be tightened until
the ring gear has cooled sufficiently.
4. INSTALL RING GEAR SET BOLTS
(a) After the ring gear has cooled sufficiently, install 10 new ringgear set bolts to which thread lock has been applied.
Thread lock:
Part No. 08833±00100, THREE BOND 1360 K or
equivalent.
NOTICE: New ring gear set bolts should be used in every case.
(b) Torque the 10 set bolts uniformly and a little at a time.
Torque: 64 N Vm (650 kgf Vcm, 47 ft Vlbf)
(c) Tighten the bolts an additional 60±90
.
NOTICE: Tighten the bolts in diagonally opposite pairs.
SA±94±
SUSPENSION AND AXLE REAR DIFFERENTIAL
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5. INSTALL SIDE BEARINGSUsing SST and a press, install the side bearings.
SST 09550±10012 (09252±10010, 09558±10010)09710±30050
6. INSTALL DRIVE PINION BEARING OUTER RACES AND ADJUSTING WASHER
HINT: The adjusting washer is used for adjusting the tooth
contact pattern. 42 types of washer with differential thick-
nesses are available.
First fit a washer with the same thickness as the washer
which was removed, then after checking the tooth contact
pattern, replace the washer with one of a different thickness
if necessary.
When removing an adjusting washer, be sure to replace it
with a new one.
(a) Using SST and a press, install a new adjusting washer and the front bearing outer race.
SST 09250±10011 (09252±10010, 09255±10011)
(b) Using SST and a press, install the rear bearing outer race. SST 09608±30012 (09608±04020, 09608±04100)
7. INSTALL REAR BEARING TO DRIVE PINION Using SST and a press, install the rear bearing.
SST 09502±24010
±
SUSPENSION AND AXLE REAR DIFFERENTIALSA±95
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