ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL
Rev.
7
MM-9-20
Aug
22/16
9-3. UNIVERSAL BLOCK ASSEMBLY
A.
Universal Block - Disassembly (Figure 9-3)
(1)
Remove upper and lower bearings (22) and DU washers (23) from U-block (15).
(2)
Press flapping bearings (22), spacer (24), and shims (25) from bore of U-block.
NOTE:
Flapping bearings can be removed from the universal blocks using the
Flapping Bearing Removal/Installation Tool T-0151-1 when the universal
blocks are installed on the aircraft.
(3)
Remove screws and stop blocks (21) if visual damage appears on blocks.
(4)
Remove grease fittings (20).
B.
Refer to Table 9-1 for detailed inspection requirements of the universal block assemblies.
C.
Universal Block - Assembly (Figure 9-3, Figure 9-6, Figure 9-7)
(1)
Install stop blocks (21) and secure with screws.
NOTE:
Index mark the universal blocks and retention assemblies as sets.
(2) Measure the stack up of two bearings (22) and one spacer (24) and measure the
distance between the spindle fork (refer to Figure 9-6).
(3) If the bearing and spacer stack up (DIM. X) is less than the distance between the
spindle fork (DIM. Y), add shims (25) between the bearings and the spacer to create
a zero tolerance fit.
(4)
Grease the bearings prior to installation.
NOTE:
Use an arbor press to install the flapping bearings if the main rotor hub
is disassembled. If the main rotor hub is assembled, use the Universal
Block Bearing Tool, T-0151-1, to install the flapping bearing. Refer to
Figure 9-7a,b for the use of tool T-0151-1.
(5) Lubricate (MIL-PRF-81322) the bore of the U-block. Install a DU washer (23) in the
recessed area on the "forward" side of the U-block and place the U-block in an arbor
press with the "forward side" and DU washer up. Press a flapping bearing (22) into
the U-block until it is flush with the DU washer.
NOTE:
If desired, an alignment/installation pilot (included with the tool, T-0151-
1) can be fabricated to aid in the installation of the bearing, spacer, and
shims into the universal block (refer to Figure 9-7c).
(6) Rotate the U-block in the press and install the spacer (24) and shims (25), if
required. Press the other flapping bearing into the bore until seated against the
spacer. Ensure that the first flapping bearing is still flush with the DU washer.
(6)
Remove the DU washer.
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