ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL
Rev.
7
MM-10-30
Aug
22/16
D. Pitch Control – Assembly (See Figure 10-12)
(1)
Heat bearing housing (7) and install bearing (8).
NOTE:
Bearing (8) is installed with slots for removal of inner bearing section
facing outboard toward pitch link retainer. These slots are located 90° to
pivot arms of bearing housing (7) on installation.
(2)
Install snap ring (9) with opening of snap ring in line with pivot arm of bearing
housing (7).
(3)
Press pitch control bearing (5) through bearing (8) in outboard direction.
(4)
Install two wave spring washers (10) on pitch control bearing (5).
NOTE:
Assembly of the pitch link retainer and bearing can be facilitated by using
alignment pins (0.75 in/1.9 cm max. length) fabricated from 1/4 inch bolts
(1.5 in long bolt; head and threads removed).
CAUTION:
Use gloves when handling heated parts.
(5)
Heat the pitch link retainer (12) to approximately 230°F/110°C and slide it over
the bearing (14). Insert the two pins to align the bearing with the pitch link
retainer. When the retainer has cooled, push the alignment pins into the inside
of the bushing to remove.
NOTE:
If pin holes do not completely line up, gently tap ear of pitch link retainer
with plastic mallet until holes line up.
(6)
Press dowel pin (11) into pitch link retainer (12). Rotate retainer and repeat.
NOTE:
Seat dowel pins to 0.01 inch below surface of pitch link retainer. Pins must
not extend through pitch control bearing (5).
(7)
Install cotter pins (13) into pitch link retainer (12).
(8)
Install the pitch change assembly onto the tail rotor gearbox output shaft to
ensure that it will slide on the chrome shaft without binding. It is common for
the bronze pitch control bearing (5) to be slightly distorted on the inside in the
area of the pins. If this is the case, use a fine tooth (1/2) round file to dress the
bearing so it will slide freely.
(9)
Install seal (4) into outboard groove of pitch control bearing (5).
E. Pitch Control – Installation (See Figure 10-12 and Figure 10-13)
(1)
Slide seal retainer (3) onto chrome sleeve (2).
(2)
Slide seal (4) onto sleeve.
(3)
Install keys (1) in slots of sleeve (2).
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