SERVICE TRANSMISSION OIL SYSTEMS
SERVICE ENGINE AND COMBINING TRANSMIS-
Under normal conditions, transmission
shall be serviced with only one
type of oil (E253, E254.1, or
E254). Oil (E254) must be used for
temperatures below -25ºF (-32ºC).
In an emergency, if one type of oil
is in the transmission but is not
available, the other type may be used.
If the two types of oil are mixed,
the transmission oil system shall be
drained and serviced as soon as
possible, but not later than 6 hours,
after transmission operation with
If transmission has not been
operated during the past 30 minutes,
perform a 5 minute ground run (TM
55-1520-240-10). (Not applicable if
transmission is drained.)
Combining transmission and left
and right engine transmissions are
serviced at the same time through
same oil filler.
Restencil all transmissions as required
to correctly identify lubrication oil to
be used after servicing.
Open aft pylon access doors (12) (Task 2-2).
Combiner oil can drain down from oil
reservoir to combiner main housing.
Check combiner sight gage (13). If oil appears
in gage go to step 24. If oil does not appear go
to step 19.
Check engine transmission sight gages (14 and
15). If oil appears in gages, perform 5 minute
ground run (TM 55-1520-240-10), and repeat
step 18. If oil does not appear, go to step 20.