JLG G6-42P Service Manual - Manual (Page 341)

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Section 5
Adjustments
3. Compare contact patterns on ring gear teeth to
good contact patterns in Figure 5.7. If contact
patterns are not satisfactory, go to Incorrect
Contact Patterns on this page.
Correct Contact Patterns
The location of a good hand-rolled contact pattern for
a new gear set is toward toe of gear tooth and in
center, between top and bottom of tooth.
Figure 5.7.
When carrier is being operated under load, pattern
will extend approximately the full length of tooth. The
top of pattern will be near top of gear tooth.
Figure 5.8.
Figure 5.7
Figure 5.8
The location of a good hand-rolled pattern for a used
gears set must match wear pattern in ring gear. The
contact pattern will be smaller in area than the wear
pattern.
Incorrect Contact Patterns
High Contact Pattern:
A high contact pattern indicated that drive pinion was
not installed deep enough into carrier. Figure 5.9.
•
To correct a high-contact pattern, decrease
thickness of shim pack under bearing cage. This
will move drive pinion toward ring gear.
Figure 5.10.
Figure 5.9
Figure 5.10
DECREASE SHIM
PACK THICKNESS