Hartzell HC-B3-2 Series Owner's Manual And Logbook page 127

CAUTION:
4 Slide the spacer onto the mounting studs and
against the hub flange.
NOTE:
(b) If the hub flange has two 8-32 threaded holes
and two MS24693-S2 flat-head screws
(HPI P/N B-3868-S52) are provided to attach the
C-7364-2 spacer, perform the following steps:
1 Coat the hub-to-spacer O-ring with grease.
Refer to Table 3-1.
2 Install the hub-to-spacer O-ring in the groove in
the spacer that interfaces with the face of the
hub flange. Refer to Figure 3-8.
3 Align the spacer attachment holes with the two
8-32 threaded holes in the hub flange.
CAUTION:
4 Slide the spacer onto the mounting studs and
against the hub flange.
INSTALLATION AND REMOVAL
Propeller Owner's Manual
139
MAKE SURE THE HUB-TO-SPACER
O-RING STAYS IN THE GROOVE
IN THE SPACER. IF THE O-RING
IS TWISTED OR PINCHED, OIL
LEAKAGE WILL RESULT WHEN
THE PROPELLER IS OPERATED
ON THE AIRCRAFT.
If the propeller installation will be
delayed, the spacer and O-ring should
be installed and temporarily held in
place with non-self locking nuts and
a sufficient number of washers on at
least two mounting studs. Remove the
nuts and washers before installation.
MAKE SURE THE HUB-TO-SPACER
O-RING STAYS IN THE GROOVE
IN THE SPACER. IF THE O-RING
IS TWISTED OR PINCHED, OIL
LEAKAGE WILL RESULT WHEN
THE PROPELLER IS OPERATED
ON THE AIRCRAFT.
61-00-39
Page 3-27
Rev. 17 Apr/20