TRUCK SERVICE MANUAL
twelve teeth is sufficient for checking purposes
With adjustments properly made, a correct tooth
contact similar to that shown in Fig. 20, will be secured. The
area of contact starts near the toe of the gear and extends
about 62 1/2 per cent of the tooth length. This adjustment
results in a quiet running gear and pinion set which, because
the load is distributed over the teeth within the proper area,
will deliver all the long service built into it.
When checking paint impressions on gear teeth of an
axle under heavy load, the impressions usually spread out
somewhat longer than the patterns obtained from a bench
test. This can be considered as normal. Ring gears when
mounted should show a bearing toward the toe or small end
of the tooth, but never at the heel or large end. The reason
being that it is practically impossible to make gears and gear
mounting so rigid that no deflection will occur when full torque
is applied. This deflection causes the bearing to approach the
heel of the tooth. When gears are adjusted so that the
bearing is toward the heel of the tooth, it results in a
concentration of load on the top corner of the heel and
breakage will follow.
Using chain sling and overhead hoist, move differential
carrier assembly from rebuild stand to roller type floor jack.
Place a new carrier to housing gasket (19) on
differential carrier (20) and roll carrier into position on the axle
housing. Install the housing bolts and lockwashers and tighten
to specified torque (See "TORQUE CHART").
Fig. 20 Tooth Contact Impressions
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