IO-390-D Series Engine Maintenance Manual
© 2020 Avco Corporation. All Rights Reserved
72-20
March 2020
Page 135
IO-390-D Series Engine Maintenance Manual
O.
Piston Cooling Nozzle Removal
Remove the four piston cooling oil nozzles from the crankcase (Figure 19).
Figure 19
Piston Cooling Nozzles
4.
Crankshaft Disassembly
WARNING
USE CARE WHEN HANDLING THE CRANKSHAFT AND ITS PARTS – DO
NOT ETCH OR MAKE MARKS ON THE CRANKSHAFT OR
COUNTERWEIGHTS. AN ETCH OR A MARK CAN CAUSE WEAKNESS
AND FATIGUE IN THE CRANKSHAFT, WHICH COULD CAUSE
CRANKSHAFT FAILURE.
A.
Bend the tabs of the crankshaft gear bolt lockplate
down, flat against the crankshaft gear.
B.
Remove the crankshaft gear bolt, lockplate, and
crankshaft gear from the crankshaft (Figure 20).
Discard the bolt and the lockplate.
NOTICE:
Any time the crankshaft gear bolt (Figure
20) is removed from the crankshaft, discard
this bolt and replace it with a new bolt
during assembly.
Do not remove the alignment dowel
(Figure 20) from the end of the crankshaft
unless it is damaged. Replace a damaged
alignment dowel per the “Alignment
Dowel Replacement” procedure in this
chapter.
Do not remove the propeller flange
bushings unless they are loose or damaged
(Chapter 72-15).
Figure 20
Crankshaft Gear and Associate Parts
