TM 9-4120-399-14
(4) Install two flat washers (3), two lock washers (2), and two nuts (1).
c. Adjustment.
( 1 ) Loosen set screws on damper shaft.
(2) Hand position butterfly to fully closed position.
NOTE
Damper butterfly should appear to have an
eleven and five o'clock position.
( 3 ) Tighten set screws on damper shaft.