Lycoming YO-233-B2A Maintenance Manual page 166

(12) Install the new 0.010 in. oversized Heli-Coil
(a) Use the T-shaped Inserting Tool P/N 64594 (Figure 60) and withdraw the mandrel
portion of this tool beyond the recessed section of its sleeve.
(b) Put the new 0.010 in. oversized Heli-Coil
(c) Push the mandrel to engage its slotted end with the tang of the new 0.010 in.
oversized Heli-Coil
(d) Turn the mandrel clockwise and press it forward slightly to engage the threaded end
of the new 0.010 in. oversized Heli-Coil
(e) While holding the sleeve of the tool, turn the mandrel where adjacent turns of the new
0.010 in. oversized Heli-Coil
threads and the insert is firmly on the Inserting Tool P/N 64594. Keep the new 0.010
in. oversized Heli-Coil
on the threads of the cylinder head.
(f) Turn the threaded portion of the sleeve on the tool within a half-turn from the end of
the coil on the new 0.010 in. oversized Heli-Coil
(g) Use the Inserting Tool P/N 64594 (Figure 60) to install the new 0.010 in. oversized
Heli-Coil
coil engages with the first thread.
(h) Continue to turn the Inserting Tool P/N 64594. When the face of the sleeve on the
tool is 1/16-inch away from the face of the boss, be sure to hold the Inserting Tool
P/N 64594 tightly with one hand. Use your other hand to simultaneously turn the
sleeve counter-clockwise to free the left half-turn of the new insert.
(i) Slide the sleeve toward the top of the mandrel. The new 0.010 in. oversized Heli-
®
Coil insert is installed correctly at this point if the end of the insert is visible
projecting above the boss.
(j) Continue to turn the mandrel clockwise until the insert is no longer visible above the
boss.
(k) When the top of the insert is approximately a half turn from the face of the boss,
remove the Inserting Tool P/N 64594.
(l) Use the Expanding and Staking Tool P/N 64593 (Figure 61) to stake the new installed
0.010 in. oversized Heli-Coil® insert securely in the spark plug hole as follows:
1 Fix the stop nut/adjusting screw on the Expanding and Staking Tool P/N 64593 to
limit expansion of the mandrel to within the thread gage.
72-30
Page 146
®
insert.
®
insert are in contact with each other to prevent crossed
®
insert securely on the tool to enable installation of the insert
®
insert into the spark plug hole on the cylinder head. Be sure that the first
Expanding and Staking Tool P/N 64593
YO-233-B2A Engine Maintenance Manual
TEO-540-A1A Engine Maintenance Manual
®
insert into the spark plug hole as follows:
®
insert into the recess on the tool.
®
insert.
®
insert.
Figure 61
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February 2021