TM 1-1520-238-23
5-101
5.20.
MAIN ROTOR HUB RETENTION NUT INSTALLATION – continued
5.20.3. Installation
a. Wipe grease from retainer (1) surface. Use
cloth (item 52, App F).
b. Clean oil from internal threads of 12 bolt holes
on main rotor hub retention nut (2) (para 1.47).
c. Install retention nut (2) on mast (3).
(1) Hand tighten retention nut (2) counterclock-
wise.
NOTE
Bolt holes are identified on retaining ring.
d. Install retaining ring (4).
(1) Aline tangs on retaining ring (4) with slot on
mast (3).
(2) Place retaining ring (4) on top of retention nut
(2).
(3) Aline holes. If holes in retaining ring (4) do not
aline with holes in retention nut (2), loosen
retention nut (2) until alinement is obtained.
e. Install 12 retaining ring bolts (5) in retention
nut (2).
(1) Install 12 bolts (5) through retaining ring (4)
and retention nut (2).
(2) Tighten 12 bolts (5) until they bear lightly
against retainer (1).
f. Torque 12 bolts (5) in the following order: 1, 2,
3, 4, 5, 6, 7, 8, 9, 10, 11, 12.
(1) Torque 12 bolts (5) to 90 INCH-POUNDS.
Use torque wrench.
(2) Torque 12 bolts (5) to 225 INCH-POUNDS.
Use torque wrench.
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TANG
5
4
2
M04-213-1
SLOT
3
1
10
2
11
7
3
5
9
1
8
4
6
12
5
4
2
M04-213-2
TANG
1
