SPECIAL INSPECTION CHECKLIST continued
Helicopter Serial No.:
INSPECT APU PTO CLUTCH PN 3886000-5.
a. Check APU PTO clutch for external oil or grease leaks, heat discoloration,
(1) Fluorescent-penetrant inspect if cracks are suspected.
(2) Grease discharge from covered port. None allowed.
Grease discharge from the covered port at the bottom of the PTO
clutch housing is not acceptable. This is an indication of internal leak-
age which will contaminate clutch surfaces. If grease discharge is
noted at the covered port, the clutch assembly shall be replaced.
Wetness from oil seepage at the covered port is acceptable.
External grease leakage is most likely to be at the forward lip seal and
duplex vent and will usually appear at the vent within the first 15 hours
of operation of a new clutch. Do not confuse grease at the covered port
with grease coming from the duplex vent. Grease from the duplex vent
will migrate to the covered port area. Grease may vent through the
duplex vent under certain conditions such as overfilling or operating
under high ambient temperatures. Under these conditions, wipe
grease away from the housing and perform APU MOC. Continue to
use the PTO clutch assembly.
(3) Inspect for hear discoloration. None Allowed.
Heat discoloration is usually confirmed to the duplex bearing housing
b. Visually inspect the duplex bearing area.
(1) Remove anti flail bracket and APU driveshaft IAW appropriate TM
(2) Inspect the output bearing grease seal for damage. None allowed.
(3) Manually rotate the clutch output shaft in both directions. The rotating
motion should be smooth with no roughness or binding. A light
amount of drag, caused by the shaft seal, is to be expected.
c. Visually inspect the needle-bearing area.
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