Figure 8-99 - Correct tooth contact pattern
for used gearing.
Adjust tooth contact pattern.
When disassembling, make a drawing of the gear tooth contact pattern so that when
reassembling it is possible to replicate approximately the same pattern. A correct
pattern should be clear of the toe and should center evenly along the face width
between the top land and the root. Otherwise, the length and shape of the pattern can
be highly variable and are usually considered acceptable tooth contact pattern for new
gearing-providing the pattern does not run off the tooth at any time. If necessary,
adjust the contact pattern by moving the crown gear and drive pinion. Crown gear
position controls the backlash setting. The adjustment also moves the contact pattern
along the face width of the gear tooth (
Figure 8-100
). Pinion position is determined by
the size of the pinion bearing cage shim pack. It controls contact on the tooth depth of
the gear tooth (
Figure 8-101
).
Figure 8-100 - Two incorrect patterns during adjust pinion position.
NAVEDTRA 14050A
8-91