TM 55-2840-241-23
3-20. Dismantling Engine into
Functional Assemblies
Major
a. During dismantling, examine all major func-
tional assemblies for serviceability. The condition of
an assembly can often be better determined by ex-
amination during dismantling. Signs of scoring, bur-
ning, and excessive wear or the presence of metal par-
ticles are danger signals. Thorough inspection should
be made immediately. Look for any indication of
work incorrectly performed during previous
maintenance or overhaul. Report any such indications
to the local maintenance officer.
b. Care must be exercised to prevent the entrance
of dirt and other foreign material into the engine.
Whenever practicable, temporary covers should be
used to seal all openings in the dismantled engine. All
threads, splines,
and pilot diameters should be
protected against damage. Protective covers should
be of a configuration that prohibits assembly with
mating parts without removing the covers.
c. Unless parts of a particular engine are to be held
for a special inspection discard all gaskets, lockwashers,
preformed packings, diaphragms, and cotter pins as they
are removed. These parts must not be mixed with new
parts of similar type and must not be used again. Disposi-
tion of self-locking nuts shall be determined in accod-
ance with minimum prevailing toque at reassembly.
d.
Prolonged contact with lubricating oil
(item 7, table 2-2) may cause a skin rash.
Those areas of skin and clothing that
come in contact with lubricating oil
should be thoroughly washed im-
mediately. Enclosed areas where
lubricating oil is used should be ade-
quately ventilated to keep mist and
fumes to a minimum.
Lubricating oil may soften paint upon
contact. If lubricating oil is spilled on
painted surfaces, these surfaces should
be thoroughly washed.
Remove the magnetic drain plug from the bot-
tom of the gearbox and allow oil to drain before the
engine is rotated in the turnover stand.
3-21. Combustion Section Removal.
a.
Disconnect the drain hose from the
drain valve (14, figure 3-8).
burner
b. Remove the lockwire, remove jam nut (16) and
disengage bracket (15) from the engine.
To prevent personnel injury due to
electrical chock, ensure ignition sys-
tem has been off for at least five
minutes before disconnecting the-
igniter lead. Ground the lead to the
engine using an insulated screw-
driver to dissipate any energy stored
in the exciter.
c. Disconnect the igniter lead (9) from the spark
igniter (10).
d. Remove fuel hose (8) between the firewall
shield and fuel nozzle (7).
e. If a new outer combustion case (6) is to be in-
stalled:
(1) Remove fuel nozzle (7) and spark igniter
(10) from outer combustion case (6).
(2) Remove drain valve (14) and plug (12)
the bottom of outer combution case (6), Diacard pre-
formed packing (11, 13).
f. Remove the two retaining rings (17) from outer
combustion case (6) and slide them forward on the
discharge air tubes (18).
g. Remove 24 nuts (5), one clamp (4) and 24 bolts
(1, 2) at the combustion case splitline.
h. Remove outer combustion case (6) and air
tubes (18). Separate the air tubes from the outer com-
bustion case.
i. Remove combustion liner (3) from the engine.
j. Remove seal rings (19) from the small ends of
the air tubes.
k. Remove retaining rings (17) and seal rings (20)
from the large ends of the air tubes.
NOTE
If a turbine overtemperature inspection is to be
made, complete step l.
l. Remove lockwire and two positioning plugs
(21). Lift off first stage turbine nozzle shield (22).
3-14
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