Operation and maintenance manual

Section 150-0020
SM 2149 5-02
17
WARNING
To prevent personal injury and property
damage, be sure wheel blocks, blocking
materials and lifting equipment are properly
secured and of adequate capacity to do the job
safely.
General
At first service, then every 1 000 hours (6 months),
check the following and repair or replace where
necessary:
a - Input flange for wear/damage.
b - Pinion oil seals for leaks.
c - Breather for signs of leakage or dirt ingress.
d - Leaks around joints.
e - General condition and tightness of nuts and bolts.
f - General condition of axle casing.
Oil Change Period
Note: For recommended oils, refer to Section
300-0020, LUBRICATION SYSTEM.
With new or rebuilt units, drain (preferable after a short run
to warm the oil) and refill after 100 hours of operating, then
at intervals of 2 000 hours (12 months).
Oil Level
Check oil levels every 250 hours (monthly), following
the procedure below:
1. Drive vehicle onto a level, solid concrete floor, apply
the parking brake and switch off the engine.
2. Block appropriate road wheels and turn the battery
master switch to the 'Off' position.
3. Unscrew oil filler/level plug (84) and check that oil
level is to bottom of plug hole. Add oil if necessary.
Note: As there is no oil sealing between drive head and
the hubs, the hub oil levels should be same as the
drive head. i.e. 13 mm (0.5 in) above the axle centre
line. After filling, allow oil to settle for at least 15
minutes, then re-check oil level at all points. Add oil as
necessary until levels remain constant after settling
period.
4. Raise axle until both road wheels are just off the
ground then support with suitable stands or timbers.
5. Rotate each hub so that bottom of oil filler/level
plugs (7, Fig. 2) are approximately 13 mm (0.5 in)
above axle centre line (level with diff filler/level plug).
6. Unscrew plugs and check that oil level is to bottom
of plug holes. If not, add oil to each hub through plug
holes then re-check oil level in drive head.
7. When level is correct, refit and tighten all filler/level
plugs to the specified torques, lower vehicle to ground
and remove wheel blocks.
SPECIAL TOOLS
Refer to Section 300-0070, SERVICE TOOLS, for part
numbers of helical gear tool (Figs. 17 and 18), oil seal
bumper tool (Fig. 20) and general service tools and
adhesives required. These tools and adhesives are
available from your dealer.
FAULT DIAGNOSIS
Very often, noises and vibrations originating in other parts
of the vehicle are mistakenly believed to emanate from
the drive head, with the result that time and effort is
wasted on an unnecessary dismantling operation.
Therefore, before fixing suspicion on the drive head,
investigate all other possible sources of trouble first.
Where the drive head is definitely suspect however,
draining the housing and examining the oil for metal
particles, will aid diagnosis and help to pinpoint any
malfunction. Refer to 'Diagnosis Chart'.
Centre Axle - Differential Drive Head