Isuzu N-Series. Manual - part 194

FRONT AXLE 4C-71

• To adjust backlash, loosen bearing cap bolts

slightly and move the dummy bearing (1) as
necessary.
A clearance should not be provided between
dummy bearing and bearing fitting face of the
differential cage.

2) Inspection of drive pinion and ring gear tooth

contact.

• Apply a thin coat of red check to faces of the 7

— 8 teeth of the ring gear.

• Check the impression of contact obtained on

the ring gear teeth and make necessary adjust-
ment as described below if the contact is abnor-
mal.

N4A0153E

N4A0154E

N4A0155E

4C-72 FRONT AXLE

3) Selection of Preload Adjusting Shim

• Measure the clearance between the differential

carrier and right and left side (dummy) bearings
by using a feeler gauge.
Carefully note the relationship between the val-
ues obtained through measurement at each
side and dummy bearings.

• Measure the thickness of dummy bearing and

side bearing.
Comparison should be made between the
thicknesses of dummy bearing and side bear-
ing installed in the same position.

TOOTH CONTACT

CASE

ADJUSTMENT PROCEDURE

Drive pinion is too far away 
from ring gear.

1. Move the drive pinion in to-

ward the ring gear by de-
creasing the thickness of 
pinion depth adjusting 
shims.

2. Adjust the backlash by 

moving ring gear away from 
the drive pinion.

Drive pinion is too close to 
the ring gear.

1. Move the drive pinion away 

from the ring gear by in-
creasing thickness of pinion 
depth adjusting shims.

2. Adjust the backlash by 

moving ring gear in toward 
the drive pinion.

Ring gear is too close to 
the drive pinion.

1. Move the drive pinion in to-

ward the ring gear by de-
creasing thickness of pinion 
depth adjusting shims.

2. Adjust the backlash by 

moving ring gear away from 
the drive pinion.

Ring gear is too far away 
from drive pinion.

1. Move the drive pinion away 

from the ring gear by in-
creasing thickness of pinion 
depth adjusting shims.

2. Adjust the backlash by 

moving ring gear in toward 
the drive pinion.

N4A0156E

N4A0160E

N4A0157E

N4A0161E

N4A0158E

N4A0162E

N4A0159E

N4A0163E

N4A0164E

FRONT AXLE 4C-73

When side bearing is thinner:
A + (dummy bearing thickness 

− side bearing

thickness) = (X)
When side bearing is thicker:
A 

− (side bearing thickness − dummy bearing

thickness) = (X)

• (X) + 0.025 = Shim thickness

Allowance for bearing preload at one side =
0.025

• Example of calculation

Thickness of shim available: 0.25, 0.30, 0.35, 0.5 mm
(0.009, 0.012, 0.014, 0.019 in)

13. Side Bearing Inner Race

Installer: 5-8840-2050-0
Grip: 9-8522-1608-0

14. Differential Cage Assembly and Ring Gear
15. Side Bearing Outer Race
16. Bearing Cap

1) Install bearing caps by aligning setting marks

(1) applied at disassembly.

Tighten:
Bearing cap bolt to 108 N

⋅m (11.0 kg⋅m / 80 lb⋅ft)

Legend

1. Dial gauge
2. Dummy bearing
3. Side bearing

mm (in.)

Measured Clearance A:

+0.85 (+0.033)

Suppose that the side bearing is 
thicker [thinner] than dummy 
bearing by 0.05 mm

−0.05 (−0.002) 

[+0.05 (+0.002)]

An allowance for bearing pre-
load:

+0.025 (+0.0009)

Thickness of shims to be 
installed:

0.825 (0.032) 

[0.925 (0.036)]

N4A0165E

Legend

A. Measured clearance

A

′. Shim installed position

N4A0166E

N4A0167E

4C-74 FRONT AXLE

2) Recheck the backlash. If measurement indi-

cates that the backlash deviates from the spec-
ified range, make an adjustment by shifting the
position of shims in use without varying the total
thickness.

Recheck the ring gear for run-out at the rear
face.
If the amount of run-out is excessive, repeat the
disassembly and reassembly steps.

Ring gear run-out,
Standard: 0.05 mm (0.002 in)
Limit: 0.2 mm (0.008 in)

N4A0168E

N4A0169E

N4A0170E