TM 9-2320-363-34-2
64.
65.
66.
67.
NOTE
Always check tooth contact pattern on drive side of ring gear teeth.
APPLY PRUSSIAN BLUE DYE TO APPROXIMATELY 12 TEETH OF RING GEAR (13). ROTATE
RING GEAR (13) SO MARKED GEAR TEETH ARE NEXT TO DRIVE PINION (2).
TO GET CONTACT PATTERN, ROTATE RING GEAR (13) FORWARD AND BACKWARD UNTIL
MARKED GEAR TEETH GO PAST DRIVE PINION (2) SIX TIMES. REPEAT, IF NEEDED, FOR
CLEARER PATTERN.
PATTERN
HIGH PATTERN
LOW PATTERN
NOTE
Location of good hand-rolled contact pattern for new gear set is toward toe of
gear tooth and in center between top and bottom of tooth.
Location of good hand-rolled contact pattern for used gear set must match
wear pattern in ring gear. Contact pattern will be smaller than wear pattern.
During tooth contact pattern checks, backlash can be adjusted within
specifcation limits, if needed, to change pattern location.
COMPARE CONTACT PATTERN WITH EXAMPLES SHOWN.
lF CONTACT PATTERN REQUIRES ADJUSTMENT, PERFORM DISASSEMBLY STEPS 38, 39, AND
43 THRU 45.
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