WHEELS, RIMS AND TIRES
Figure 18. - Unitized Barrier Seal
Guardian Oil Seal
The rubber encased lip type seal with wiper ring shown in
Figure 19 is known as the Guardian oil seal. It has the
grit guard feature similar to the seal shown in Figure 16,
with the advantage of a direct contact between the seal
and wiper ring to further guard against entrance of
foreign matter. The wiper ring provides a smooth
contact for the lip of the seal. The lip of the seal retains
the oil in the bearing cavity. The rubber encasement has
grooves around its circumference which retains the seal
in place in the hub. Pay special attention to the
installation of this seal found elsewhere in this section.
The wheel seals are removed using a brass drift and
hammer. Position the drift through the outer opening of
hub and against bearing. Tap bearing and seal out
through the brake drum side of hub. Take care so that
seal bore is not damaged.
The wiper or wear ring used with oil lubricated wheel
bearing is removed by using a ball peen hammer and
tapping on the ring to fatigue it. Do not use a chisel to
cut ring since it could damage the machined surface on
Figure 19. - Guardian Seal
CLEAN AND INSPECTION
Thoroughly clean all parts: axle tube or spindle,
bearings, nuts and inside of wheel hub.
All burrs from inside back edge of hub must be
removed. Hub must be smooth and free from
burrs which will scratch the outside diameter of
Remove burrs from axle tube or spindle
shoulder. Shoulder must be smooth.
Inspect for porous or cracked hub which could
allow oil leakage. This is important where
leakage has been encountered.
causes and corrections will be found in the
Wheel Seal Leakage Chart in this section.
Wheel seal Installing tools are no longer available
through Serv-Equip program. However, special seal and
wiper ring installation tools are available through Truck
Parts Marketing program.