Isuzu N-Series. Manual - part 175
REAR AXLE 4B-57
The viscous-type limited slip differential is of the struc-
ture filled with viscous (high viscosity silicone oil) be-
tween the outer plates connected to the differential case
and the inner plates connected to the side gear on the
left side. While driving, the difference in the number of
revolutions between the right and left wheels causes the
difference in the number of revolutions also between the
differential case and the side gear on the left side. This
difference in the number of revolutions results in shear-
ing of silicone oil to generate viscous torque between
the plates.
When either one of the wheels is caught up in muddy or
snow melting road and starts racing while driving, the
operation of the viscous torque mentioned above makes
it facilitate to drive the vehicle by providing a driving
force to the other wheel on the road where the road con-
dition is better.
Caution:
The LSD assembly cannot be disassembled. When
there occurs anything abnormal with the LSD assembly,
replace it as an assembly. (Please note that when the
silicone oil which has been sealed inside drains out
while in disassembly, the LSD assembly will fail to dis-
play its intrinsic performance.)
Performance Check (Except Taiwan, Australia and
GCC)
Check the performance by following the procedure giv-
en below.
1. Set the transmission gearshift lever to the neutral
position.
2. Lift up the rear axle.
3. Rotate with a gathered momentum either one of
the wheels on the rear axle in the forward direction.
When the wheel on the opposite side rotates in the for-
ward direction while in the operation of (3) above, it is
considered that the performance of viscous coupling
functions normally, and otherwise, that the viscous cou-
pling has a lowered performance.
Warning:
WARNING:
WHEN EITHER ONE OF THE REAR WHEELS IS LIFT-
ED UP AND A DRIVING FORCE IS APPLIED TO THE
REAR AXLE, THE VEHICLE IS IN DANGER OF
STARTING ABRUPTLY. BE SURE NOT TO APPLY A
DRIVING FORCE TO THE REAR AXLE IN THIS CON-
DITION.
For detailed information of disassembling, assembling,
checking and servicing of parts other than the LSD as-
sembly, refer to “292 MM DIFFERENTIAL”.
Rear Axle Shaft (Except 2003 year model)
Notice:
For vehicles provided with the LSD assembly, the length
of the rear axle shafts is different from each other on the
right and left sides. Be careful not to confuse one with
another when replacing the rear axle shaft.
L (in the illustration)
Right side: 800
± 2 mm (31.5 ± 0.08 in)
Left side: 856
± 2 mm (33.7 ± 0.08 in)
N4A0208E