300Tdi Discovery
REAR AXLE AND FINAL DRIVE
1
FAULT DIAGNOSIS
FAULT DIAGNOSIS
Complaint - Oil leaks
An external leak of lubrication from the hub seals can
be caused by a faulty internal seal. For example, if the
internal seals which separate the differential from the
hubs are faulty and the vehicle is operating or parked
on an embankment. Oil from the differential may flood
one hub causing a leak and leave the differential
lacking lubrication.
When a seal is found to be leaking check the axle
ventilation system, as a blockage can cause internal
pressure to force oil past the seals.
See ’Description and Operation’ for illustrations of oil
seal locations.
When investigating hub seal leaks check the grease
for dilution with oil. Check also the differential level
and oil for metal particles and the condition of internal
seals.
If the vehicle is driven in deep water with defective oil
seals, water may contaminate the lubricants and raise
the differential level giving a false impression that the
housing has been overfilled with oil.
Do not assume that a high oil level in the
differential is due to over filling or, that a low level
is because of an external leak.
