2004 ISUZU TF SERIES differential

REAR AXLE 4B-35

Reassembly
1. Install side gear with thrust washer in differential
cage.
2. Install the pinion gear by engaging it with the side
gears while turning both pinion gears
simultaneously in the same direction.


425RS048

3. Install cross pin.


Be sure to install the cross pin so that it is in
alignment with the lock pin hole in the
differential cage.




425RS049

4. Check the amount of backlash.
Backlash between the side gear and the pinion
gear. mm (in)

0.13-0.18 (0.005-0.007)
If the backlash is beyond the limits, adjust with a thrust
washer of selected thickness.
Thicknesses of thrust washers available.
Backlash mm (in
)

0.80
(0.031)0.90
(0.035)1.00
(0.039) 1.10
(0.043) 1.20
(0.047)1.30
(0.051)





425RY00008

5. Install lock pin.
After lock pin installation, stake the case to
secure the lock pin.
6. Install ring gear.
Refer to “Ring gear replacement” on this section.

4B-36 REAR AXLE

LIMITED SLIP DIFFERENTIAL (LSD)
Disassembled View
425R300007
Legend

1. Screw
2. Differential Cage B
3. Thrust Washer
4. Spring Plate
5. Spring Plate
6. Friction plate
7. Friction disc
8. Friction plate
9. Friction disc
10. Pressure Ring
11. Side Gear
12. Pinion and Pinion Shaft
13. Side Gear
14. Pressure Ring
15. Friction Disc
16. Friction Plate
17. Friction Disc
18. Friction Plate
19. Spring Plate
20. Spring Plate
21. Thrust Washer
22. Differential Cage A

REAR AXLE 4B-37

Disassembly

Prepare a side gear holder : 5-8840-2682-0 as
shown in the left figure, clamp it with a stock vice,
and set a differential.
425R300008

1. Screw


Apply a setting mark to the differential cage
A and differential cage B remove the bolt
using the press.


Loosen four screws fixing differential cage A
to cage B equally and remove them.

425RS055

2. Remove differential cage A and B.
3. Remove thrust washer and two spring plates.
4. Remove friction plate and friction disc.
5. Remove friction plate and friction disc.
6. Remove pressure ring and side gear.
7. Remove pinion and pinion shaft.
8. Remove side gear and pressure ring.
9. Remove friction disc and friction plate.
10. Remove friction disc and friction plate.
11. Remove two spring plates and thrust washer.

4B-38 REAR AXLE

Inspection and Repair
Make all necessary adjustments, repairs, and part
replacements if wear, damage, rust or other problems
are discovered during inspection.

Visual Check
Inspect the following parts for wear, damage or other
abnormal conditions.


Friction disc


Friction plate


Spring plate
1 Sliding surface
2 Protrusion




425RS056

Pressure ring
Check the parts for damage or other abnormal
conditions.
3 Sliding surface for friction disc
If dents or damages are discovered, grind them
with oil stone, and repair them with compound on
surface plate.
4 Sliding surface of pressure ring inner surface and
pinion gear.
5 Slinding surface of pressure ring bore and side
gear.
6 sliding surface of pressure ring and side gear.
7 Sliding surface of pressure ring and pinion shaft.
8 Mating surface to differential cage A.
9 Burrs or dents on sliding surface of pressure ring
and rear differential cage should be repaired,
using oil stone.

425RY00022



Thrust Washer
10 Groove on side gear circumference small burrs of
dens should be repaired, using oil stone.
11 Sliding surface between side gear and thrust
washer.
425RY00024



Differential cage A and B
12 Contact surface to spring plate
13 Differential cage A and B contact surfaces to
thrust washers Small burrs or dents should be
repair, using oil stone.

4B-40 REAR AXLE




425RS063


Reassembly
Adjustment of Clearance between
Friction Disc and Plate
1. Measuring depth of differential case
mm(in)

Standard (A-B) 80.58 (3.17)
(C) 10.58 (0.42)



425RS064

2. Measuring overall length of pressure ring, friction
disc and plate assembly

Assemble pinion shaft with pressure ring,
then friction disc and plate.


Measure length between plates at both ends
over V-shape groove. (D)




425
RS065

3. After A, B, C and D dimensions are measured,
perform adjustment with the following procedure.


Measure spring plate :
1.75 mm (0.69 in) 
4 pcs (E)


Measure thickness of plate spring
Standard dimension :
1.75 mm (0.069 in) 
2 pcs (F)
4. Select a friction disc or plate so that ((A-B+C) -
(D+E) = 0.06 to 0.20 mm (0.002 to 0.008 in.) and
also the difference in total dimension of friction
disc and plate and spring plate (left/right side)
does not exceed 0.05 mm (0.002 in.).
Thickness : 1.65, 1.75, 1.85 mm (0.065, 0.069,
0.073 in)

Adjusting Backlash of Side Gear in
Axial Direction
1. Measuring depth of differential case
mm(in)

Standard (F-B) 82.03 (3.23)
(G) 12.03 (0.47)

REAR AXLE 4B-41



425RS066

2. Measuring dimension between thrust washers at
both ends.
Assemble side gear, pinion, pinion shaft pressure
ring and thrust washer.

Eliminate clearance by pushing pressure ring
against the pinion shaft in axial direction.


Eliminate backlash by connecting side gear to
the pinion.


Measure dimension between thrust washers at
both ends. (H)




425RS067

3. After each dimension is measured, perform
adjustment with the following procedure.
Adjust so that ((F-B) + G-H) = 0.05 to 0.2 mm
(0.002 to 0.008 in). Also, select a proper thrust
washer so that the dimension difference from
back face of the pressure ring to thrust washer
(left/right side) does not exceed 0.05 mm (0.002
in).
Thickness : 1.5, 1.6, 1.7 mm (0.059, 0.063,
0.067 in)

Note :
When reassembling, sufficiently apply gear oil on
every part, especially on sliding surface.
1. Install thrust washer in differential cage A and
B.
2. Assemble spring plate, friction plate and
friction disc as following illustration.





Install spring plate with dished side turned
to the differential cage side.
425R300009
Legend

1. Friction Plate
2. Spring Plate
3. Friction Disc

4. Install pressure ring and side gear.


Fit two side gears in two pressure rings, one
from under a ring and the other from above a
ring.


Fit two pairs of a friction disc and a friction
plate under it on and under these two pressure
rings.
5. Set pinion and pinion shaft on differential cage A
assembly.
6. Assemble differential cage A and B.
7. Align the setting marks on differential cage A and
B and tighten screws in diagonal order evenly.

REAR AXLE 4B-43

TROUBLESHOOTING
Refer to this Section to quickly diagnose and repair
rear axle problems.
Each troubleshooting chart has three headings
arranged from left to right.
(1) Checkpoint
(2) Trouble Cause
(3) Countermeasure
This Section is divided into five sub-sections:
1. Abnormal Rear Axle Noise
1) Noise when the engine is driving the vehicle
2) Noise when the vehicle is coasting
3) Intermittent noise
4) Noise when the vehicle is turning
5) Constant noise
2. Vibration
3. Oil Leakage
1) Differential carrier leakage
2) Axle case leakage
3) Axle case to inside hub leakage
4) Axle case to inside brake drum leakage
4. Power Not Being Transmitted to the Wheels
(Propeller Shaft Operation is Normal)

4B-44 REAR AXLE

1. ABNORMAL REAR AXLE NOISE
1) Noise when the Engine is Driving the Vehicle

Checkpoint Trouble Cause Countermeasure

Replenish the gear oilInsufficient gear oil NG
Differential side bearingAdjust the differential side
bearing preload
Replace the drive pinion
bearings
Adjust the drive pinion bearing
preload
Replace the gear oil
Loose differential side
bearings
Worn drive pinion bearings
Loose drive pinion bearings
Wrong or poor grade gear oil
Drive pinion to ring gear
backlash
Drive pinion end play
Adjust the backlashToo much or too little backlash
Continued on the next pageOK OK
NG NG NG NG NG
OK
OK
Rear axle gear oil
Replace the differential side
bearingsWorn differential side bearings NG