TM 55-1520-240-23-5
6-136
CONTAMINATION ANALYSIS OF AFT TRANSMISSION OIL
6-136
INITIAL SETUP
Applicable Configurations:
All
Tools:
Magnet
Magnifying Glass, 12 Power
Materials:
None
Personnel Required:
Inspector
Equipment Condition:
Off Helicopter Task
1.
Solid particles found in the transmission oil
system may be steel, magnesium, aluminum,
silver, copper, bronze, or fiberglass. Examine
particles as follows:
a.
Separate steel particles. Use a magnet.
b.
Identify and separate remaining particles by
visual inspection.
c.
Examine particles with a magnifying glass
to determine shape and condition. Look for
marks or discoloration that may indicate
shearing, burning, or fatigue.
MATERIAL
DESCRIPTION
ACTION REQUIRED
Steel
Fine, hair-like fuzz particles
Normal wear. No action required
Limited amount of splinters, flakes, or
granular particles
Possible failure. Perform serviceability check
(Task 6-140)
Thin flakes up to 1/16 inch in diameter and
1/4 inch long, maximum of 10 flakes
Perform serviceability check (Task 6-140)
Massive amount of splinters, flakes, or
granular particles
Failure. Replace transmission (Task 6-92
and Task 6-97) or aft rotor shaft (Tasks 6-56
and 6-62)
Aluminum or magnesium
Granular particles
Perform serviceability check (Task 6-140)
Massive amounts of splinters, flakes or
granular particles.
Failure. Replace transmission (Tasks 6-92
and 6-97) or aft rotor shaft (Tasks 6-56 and
6-62)
Copper, bronze, or silver
Limited amount of granular particles
Possible indication of bearing cage wear.
Perform serviceability check (Task 6-140)
Massive amount of granular particles or chip
particles
Failure. Replace transmission (Tasks 6-92
and 6-97) or aft rotor shaft (Tasks 6-56 and
6-62)
Fiberglass
Granular or fibrous particles
Perform serviceability check (Task 6-140)
FOLLOW-ON MAINTENANCE:
None
END OF TASK
6-500
