TM 1-1520-238-23
6-438
Change 4
6.99.
MAIN ROTOR MAST MOUNTING BOLT REPLACEMENT (AVIM) – continued
6.99.3. Removal
a. Remove retainer (1) from mast base (2).
(1) Remove lockwire from six screws (3).
(2) Remove six screws (3) and washers (4).
(3) Remove retainer (1).
b. Remove 18 bolts (5) and washers (6) from
mast base (2).
6.99.4. Cleaning
a. Clean bolts, washers, base, and retainer (para
1.47).
6.99.5. Inspection
a. Check for cracks. None allowed.
b. Check for thread damage. None allowed.
6.99.6. Installation
a. Lubricate shank and threads of 18 bolts (5).
Use lubricant (item 114, App F).
(1) Allow lubricated bolts to cure for 6 HOURS at
room temperature, or air dry for 30 MINUTES
and then cure for 30 MINUTES at 150 F (66
C).
b. Apply sealing compound to bolt heads (5) at
shank radius. Use sealing compound (item 177,
App F).
c. Install washers (6) on bolts (5) and apply seal-
ing compound on shank 1 INCH from bolt
head. Use sealing compound (item 177, App F).
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