TM 55-1520-240-23-5
6-140
AFT TRANSMISSION SERVICEABILITY CHECK (Continued)
6-140
1.
Drain oil through cheesecloth (E112) or similar
filter material (Task 6-138). Check for debris.
2.
Remove and clean debris detection screen cap
(1) (Task 6-157). Install cap (Task 6-158).
3.
Replace element in main oil filter (2) (Task
6-148). Note position of indicator button (3). If
button is extended, remove and inspect inlet
screen (4) (Tasks 6-157 and 6-131). Install
screen (Task 6-156).
4.
Replace auxiliary oil filter (5) (Task 6-154).
5.
Service transmission (Task 1-54).
6.
Have pilot perform ground run for 1 hour
at normal rotor rpm (TM 1-1520-240-10). If
forward transmission oil pressure or temperature
changes abnormally or if debris screen or chip
detector light comes on, have pilot shut down
helicopter. Check for cause.
7.
Drain oil through cheesecloth (E112) or similar
filter material (Task 6-138). Check for debris.
8.
Remove, inspect, and clean debris screen cap
(1) (Task 6-157). Install cap (Task 6-158).
9.
Remove element in main oil filter (2). If element
contains debris or filter button (3) was extended,
replace with new element (Task 6-148).
10.
If element in filter (2) contains debris and filter
button (3) was also extend, remove, inspect, and
install inlet screen (4) (Tasks 6-155, 6-131, and
6-156).
11.
Replace auxiliary oil filter (5) (Task 6-154).
12.
If quantity and size of particles obtained from oil
filters (2 and 5) and cap (1) have not decreased
by at least 30 percent from original amount,
replace aft transmission (Tasks 6-92 and 6-97).
13.
If quantity and size of particles obtained from oil
filters (2 and 5) and cap (1) have decreased by
30 percent or more, repeat steps 1 thru 11. If
any debris is obtained replace aft transmission
(Tasks 6-92 and 6-97).
FOLLOW-ON MAINTENANCE:
Close cargo ramp (Task 2-2).
Install aft transmission drip pan (Task 2-3).
Close baffles under aft transmission (Task 2-2).
END OF TASK
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