TM 1-1520-238-23
5-256.6
Change 1
5.57A.
TAIL ROTOR HUB ASSEMBLY REMOVAL/INSTALLATION (AVIM) – continued
b. Center strap pack (10) in hub (6).
(1) Place gage blocks (21) under each end of
strap pack (10) so long ends of gage blocks
(21) contact each end of hub (6).
(2) Install two spare bolts (22) through each end
of strap pack (10).
(a) Position spare bolts (22) so that un-
treated portion is next to upper legs of
gage block (21).
(3) Shim four places using thickness gage to ob-
tain equal clearance between gage blocks
(21) and spare bolts (22). Use enough gage
thickness to stretch strap pack (10) taut in
hub (6).
(4) Alternately tighten each threaded bushing
(20) until final torque of 40 to 60 INCH-
POUNDS is reached on each bushing (20).
Use torque wrench and torque adapters sup-
plied in centering kit.
(5) Check for equal clearance between gage
block (21) and spare bolt (22) at each end of
hub (6). Use thickness gage.
(a) Strap pack must be within 0.005 INCH of
each end of hub (6).
(6) Remove bolt (11) from hub (6).
(a) Bolt (11) must move freely in hub (6),
bushings (20), and strap pack (10).
(7) Remove threaded bushings (20) from hub
(6). Use torque adapters supplied in
centering kit.
(8) Apply primer to threads of bushing (20) and
threads of hub (6). Use brush (item 34,
App F) and sealing compound primer
(item 146, App F).
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TORQUE ADAPTER
TORQUE WRENCH
20
11
6
21
22
M04-3245-4
THICKNESS GAGE (TYPICAL 4 PLACES)
10
