DIFFERENTIAL (REAR)4A2±9
3. Install oil seal. Note direction.
4. Install bearing assembly, using installer and press.
420RS030
NOTE: Install bearing with cup towards inboard side.
420RS031
5. Install retainer ring, using installer and press.
420RS033
6. Install snap ring.
7. Install axle shaft assembly into housing.
8. Install bolts, lockwashers, and nuts.
Tighten the retainer nuts to the specified torque.
Torque : 75 N´m (55 lb ft)
4A2±10DIFFERNTIAL (REAR)
Pinion Oil Seal
Pinion Oil Seal and Associated Parts
420RW013
Legend
(1) Flange Nut and Washer
(2) Flange(3) Oil Seal
(4) Outer Oil Seal Slinger
(5) Outer Pinion Bearing (Cup and Cone)
Removal
1. Remove the rear propeller shaft. Refer to Rear
Propeller Shaft
in this section.
2. Drain the rear axle oil.
3. Check and record preload with an inch pound torque
wrench. This will give combined pinion bearing, seal,
carrier bearing, axle bearing and seal preload.
425RW018
DIFFERENTIAL (REAR)4A2±13
Differential Assembly
Disassembled View
420RW018
Legend
(1) ABS Speed Sensor
(2) Housing
(3) Outer Pinion Bearing (Cup and Cone)
(4) Outer Oil Slinger
(5) Oil Seal
(6) Companion Flange Assembly
(7) Pinion Nut Washer
(8) Pinion Nut
(9) Collapsible Spacer
(10) Baffle Plate
(11) Inner Pinion Bearing (Cup and Cone)
(12) Inner Oil Slinger
(13) Pinion gear adj. Shim-Selective (Position)
(14) Ring gear and Pinion Gear Assembly
(15) Exciter Ring
(16) Differential Case(17) Lock Pin
(18) Axle Vent
(19) Gasket
(20) Cover and Clip Assembly
(21) Fill Plug (with Magnet)
(22) Mounting Bracket
(23) Side Bearing Cap Bolt
(24) Side Bearing Cap
(25) Ring Gear Bolts
(26) Differential Adjustment Shims (Side Bearing
Preload and Ring Gear/Pinion Backlash)
(27) Side Bearing (Cup and Cone)
(28) Differential Shaft
(29) Differential Side Gears
(30) Side Gear Thrust Washer
(31) Pinion Mate Gears
(32) Thrustwasher-Differential Pinion Mate Gear
4A2±14DIFFERNTIAL (REAR)
Inspecting the Axle Before
Disassembly
1. Remove the axle cover from the rear axle and drain
the axle lubricant into a suitable container.
2. Check ring gear backlash. Refer to
Backlash
Adjustment
in this section. This information can be
used to determine the cause of the axle problem. It
will also help when setting up the shim packs for
locating and preloading the differential cage.
3. Check case for metal chips and shavings. Determine
where these chips and shavings come from, such as
a broken gear or bearing cage.
If possible, determine the cause of the axle problem
before disassembly.
Disassembly
1. Remove axle shafts.
Refer to
axle shaft replacement in this section.
2. Remove ABS sensor.
3. Remove bearing caps and bolts.
Mark the caps and the housing as left and right.
CAUTION: Be a ri n g c a p s a re machined with the
housing and must be assembled in the same
position as removed. Note the matched letter
stamped on the caps and carrier. When assembled,
the letters on the caps must agree in both the
hosizontal and vertical position with the letters on
the carrier.
420RW003
4. Remove Differential case.
Pry the case from the axle housing at the differential
ªwindowº.
420RW010
5. Remove side bearing outer races and shims.
Mark the races and shims as left and right, and
place them with the bearing cups.
6. Remove differential side bearings using remover
J±42379 and plug J±39830.
Select insert ; 303174 and collet halves ; 44801 in
remover kit J±42379.
415RW003
7. Remove ring gear bolts.
Ring gear bolts use right handed threads.
CAUTION: DO not pry the ring gear from the case.
This will damage the ring and the differential case.
4A2±16DIFFERNTIAL (REAR)
16. Remove exciter ring.
Remove the exciter ring from the differential using a
mallet or a brass hammer if it is required.
NOTE: Discard the exciter ring after removal.
425RS097
Cleaning
Do not steam clean drive parts which have ground and
polished surfaces such as gears, bearings, and shafts.
These parts should be cleaned in a suitable solvent. All
parts should be disassembled before cleaning.
Parts should be thoroughly dried immediately after
cleaning. Use soft, clean, lintless rags. Parts may be dried
with cimpressed air. Do not allow the bearings to spin
while drying them with compressed air.
Inspection and Repair
It is very important to carefully and thoroughly inspect all
drive unit parts before reassembly.
Thorough inspection of the drive parts for wear or stress
and subsequent replacement of worn parts will eliminate
costly drive component repair after reassembly.
Axle Housing
The carrier bore for nicks or burrs that would prevent
the outer diameter of the pinion seal from sealing,
Remove any burrs that are found.
The bearing cap bores for nicks or burrs.
Remove any burrs that are found.
The housing for cracks. Replace the housing if any
cracks are found.
The housing for foreign material such as metal chips,
dirt, or rust.
Pinion and Ring Gear
Pinion and ring gear teeth for cracking, chipping,
scoring, or excessive wear.
Pinion splines for wear.
Pinion flange splines for wear.The sealing surface of the pinion flange for nicks,
burrs, or rough tool marks which would cause
damage to the seal's inside diameter and result in an
oil leak.
Replace all worn or broken parts.
Ring and pinion gears are matched sets and are both
replaced anytime a replacement of either is
necessary.
Bearings
Bearings visually and by feel.
The bearings should feel smooth when oiled and
rotated while applying as much hand pressure as
possible.
The large end of the bearing rollers for wear.
This is where tapered roller bearing wear is most
evident.
Bearing cups for wear, cracks, brinelling and scoring.
Bearing and cups are only replaced as sets.
If the rear axle was operated for an extended period of
time with very loose bearings, the ring gear and drive
pinion will also require replacement.
Low mileage bearings may have minute scratches
and pits on the rollers and the bearing cups from the
initial pre-load. Do not replace a bearing for this
reason.
Bearing cups for cracks or chips.
Shims
Shims for cracks and chips. Damaged shims should
be replaced with an equally sized service shim.
Reassembly
1. Install pinion bearing races and baffle plate using
outer bearing race installer J±8611±01 / inner bearing
race installer J±42836 and drive handle J±8592.
NOTE: Baffle plate must be installed, when install the
inner pinion bearing race.
425RW019
DIFFERENTIAL (REAR)4A2±29
12. Remove differential plate retainer from both clutch
packs to allow separation of the plates and discs.
NOTE:
Keep the discs and plates in the same order as they
were removed.
425RW009
Legend
(1) Differential Plate
(2) Differential Disc
(3) Dished Spacer
(4) Side Gear
Inspection and Repair
Cleaning
All parts with solvent.
Visual Inspection
Clean all parts with solvent.
Plates and Discs. If any one disc or plate in either
stack shows evidence of excessive wear or scoring,
the complete stack is to be replaced on both sides.
Side Gears and Pinion Mate Gears. The gear teeth of
these parts should be checked for extreme wear and
possible cracks. The external teeth of the side gear,
which retain the concentric groove discs, should also
be checked for wear or cracks.
If replacement of one gear is required due to wear,
etc., then both side gears, pinion mate gears, and
thrust washers are to be replaced.
Differential Shaft. If excessive wear is evident, the
differential shaft should be replaced.
Differential Plate Retainers. If wear is evident on any
one of the differential plate retainers, all four retainers
must be replaced.
Differential Case. If scoring, wear or metal pickup is
evident on the machined surfaces, replacement of
the case is necessary.
Reassembly
1. Lubricate thrust face of side gears, plates and discs
with the proper limited slip rear axle lubricant.
2. Assemble plates and discs in exactly in the same
position as they were removed, regardless of whether
they are new or original.
3. Install differential plate retainer to ears of plates.
NOTE:
Make sure both retainers are Completely seated on
ears of plates.
4. Install clutch pack and side gear into bottom side gear
bore. Make sure clutch pack stays assembled to side
gear splines, and that retainers are completely seated
into pockets of case.
NOTE:
To prevent clutch pack from falling out of case, hold
clutch pack in place by hand while repositioning case
on bench.
5. Install other side gear and clutch pack. Make sure
clutch pack stays assembled to side gear splines, and
retainers are completely seated into pockets of case.
6. Hold clutch pack in position and assemble screw cap
J±34174±2, cap J±34174±1 and forcing screw
J±22342±15. Tighten forcing screw into bottom cap
to hold both clutch packs in position.
7. With tools assembled to case, position case on holder
J±39824 by aligning splines of side gear with those of
shaft. Tighten forcing screw to compress clutch packs
in order to provide clearance for pinion mate gears.
901RW069
8. Install pinion mate gears.
Place the pinion mate gears into the differential 180
degrees apart.
4B1±1
DRIVELINE CONTROL SYSTEM
AXIOM
DRIVELINE/AXLE
DRIVELINE CONTROL SYSTEM
CONTENTS
Service Precaution 4B1±1. . . . . . . . . . . . . . . . . . . . . .
Shift On The Fly System 4B1±2. . . . . . . . . . . . . . . . .
Outline of Shift on The Fly System 4B1±2. . . . . . . . .
Functions of Indicator Lamp 4B1±4. . . . . . . . . . . . . .
Shift On The Fly Electrical Equipment 4B1±5. . . . . .
Axle Shaft Connection and Disconnection 4B1±5. . Shift On The Fly Controller 4B1±7. . . . . . . . . . . . . . .
Shift On The Fly Controller and
Associated Parts 4B1±7. . . . . . . . . . . . . . . . . . . . . .
Removal 4B1±7. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 4B1±7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Precaution
WARNING: THIS VEHICLE HAS A SUPPLEMENTAL
RESTRAINT SYSTEM (SRS). REFER TO THE SRS
COMPONENT AND WIRING LOCATION VIEW IN
ORDER TO DETERMINE WHETHER YOU ARE
PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING. WHEN YOU
ARE PERFORMING SERVICE ON OR NEAR THE SRS
COMPONENTS OR THE SRS WIRING, REFER TO
THE SRS SERVICE INFORMATION. FAILURE TO
FOLLOW WARNINGS COULD RESULT IN POSSIBLE
AIR BAG DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.
4B1±2
DRIVELINE CONTROL SYSTEM
Shift On The Fly System
Outline of Shift on The Fly System
The shift on the fly system switches between 2 wheel
drive (2WD) and 4 wheel drive (4WD) electronically by the
driver turning the TOD switch on the instrument panel.
This system will control the following operations. (Shifting
between ª4Hº and ª4Lº must be performed by TOD
switch.)
1. Transmitting the torque to the front propeller shaft.
2. Connecting front wheels to, and disconnecting them
from, the front axles by axle motor actuator.
3. Indicating on instrument panel.
4. 4WD out signal to other Electronic Brake Control
Module (EBCM).
System Diagrams
412R200008