IO-390-D Series Engine Maintenance Manual
© 2020 Avco Corporation. All Rights Reserved
72-20
March 2020
Page 131
IO-390-D Series Engine Maintenance Manual
G.
Remove the camshaft when the crankcase halves are separated enough to allow for removal
(Figure 7).
H.
Remove the camshaft tachometer shaft, spacer, pin, and internal retaining ring. Discard the
internal retaining ring, spacer, and pin.
I.
Continue separating the crankcase halves until the crankshaft can be removed from the
crankcase (Figure 8).
Figure 7
Remove the Camshaft
Figure 8
Remove the Crankshaft
J.
Put the crankshaft in a suitable V-block-
type fixture as shown in Figure 9.
NOTICE:
Undersize crankshafts are
identified by a code symbol
stamped on the front of the
flange as a suffix to the part
number. In addition to the code
symbols, the letters "RN" are
stamped as a suffix to the
crankshaft serial number,
indicating that the crankshaft
has been renitrided.
Figure 9
Crankshaft in V-Block-Type Fixture
K.
Tappet, Main Bearing and O-Ring Removal
(1)
Remove the hydraulic tappet plungers using the Tappet Assembly Tool P/N 64941.
CAUTION
IF A TAPPET ASSEMBLY TOOL IS NOT AVAILABLE, REMOVE
THE PUSH ROD SOCKETS BY HAND OR BY MAKING A LOOP
FROM A SHORT LENGTH OF SAFETY WIRE. DO NOT USE A
MAGNET TO REMOVE THE SOCKET OR THE PLUNGER
ASSEMBLY FROM THE ENGINE, AS THIS COULD CAUSE THE
BALL TO REMAIN OFF ITS SEAT AND MAKE THE UNIT
INOPERATIVE.
(2)
Remove the push rod socket (Figure 10) by placing heavy grease on the ball end of the
Tappet Assembly Tool. Push the greased ball end of the Tappet Assembly Tool into the
socket and withdraw it. The socket will adhere to the grease.
