TM 1-1520-238-23
Change 4
6-23
6.4.
MAIN TRANSMISSION TAIL ROTOR COUPLING REMOVAL/INSTALLATION – continued
CAUTION
When installing tail rotor coupling, ensure
that bolts are installed through 0.250
INCH bolt holes on main transmission
output flange and on coupling aft flange.
Do not install bolts through any of 0.500
INCH lightning holes. Installation of bolts
through lightning holes will result in fail-
ure of drive shaft and/or coupling.
b. Install coupling (1). Torque bolts (2) and (4) to
125 INCH-POUNDS.
(1) Position coupling (1) between flange (3) and
shaft (5) with nutplates (12) facing forward.
(2) Install five bolts (4) through coupling (1) aft
flange and shaft (5).
(3) Install five bolts (2) through flange (3) and
coupling (1) forward flange.
(4) Torque bolts (2) and (4) to 125 INCH-
POUNDS. Use torque wrench adapter and
torque wrench.
(5) Apply corrosion preventive compound to
bolts (2) and (4). Use corrosion preventive
compound (item 62A, App F).
c. Inspect (QA).
d. Secure forward catwalk (para 2.84).
e. Secure access doors T250L, T250R, T290L,
T290R, and L325 (para 2.2).
f. Perform drive system vibration maintenance
operational check (TM 1-1520-238-T).
END OF TASK
M04-0435-3
5
2
3
1
4
12
