IO-390-D Series Engine Maintenance Manual
© 2020 Avco Corporation. All Rights Reserved
72-20
March 2020
Page 169
IO-390-D Series Engine Maintenance Manual
20.
Propeller Governor Drive Installation (Engines with Front-Mounted Propeller Governor Drives)
NOTICE:
Examine each component to be installed on the propeller governor assembly. Replace
any damaged or worn part with a new part. The gear assembly was to have been
installed in the left crankcase half before crankcase assembly.
The following
new
parts must be available to install the propeller governor drive
(Figure 12):
•
Four lock washers
•
Dowel pin (larger)
•
Thrust washer
(different thickness sizes available - Table 2 - requires
measurement of clearance in subsequent steps to
identify the correct thrust washer)
•
Governor gasket
•
Dowel pin (smaller)
•
Idler gear gasket
•
Set screw
Table 2
Thrust Washer Thickness
Thrust Washer Part Number
Thrust Washer Thickness
in.
mm
73249
0.0585 to 0.0595
1.4859 to 1.5113
73250
0.062 to 0.063
1.575 to 1.600
73251
0.0655 to 0.0665
1.6637 to 1.6891
73252
0.069 to 0.070
1.753 to 1.778
01L21418
0.055 to 0.056
1.397 to 1.422
A.
Governor Drive Gear Installation
(1)
Lubricate the shaft of the governor drive gear with
engine oil and install the governor drive gear in the
left half of the crankcase.
(2)
Apply Lubriko M-6 grease or equivalent to the rear
face of the propeller governor idler gear.
(3)
Install the propeller governor idler gear assembly,
and thrust washer into the crankcase (Figure 67).
(4)
Install the propeller governor idler shaft into the
crankcase through the propeller governor idler gear
assembly and thrust washer (Figure 68).
(5)
Use the thickest thrust washer to keep the backlash
at a low limit.
B.
Backlash Check:
NOTICE:
Refer to Section IV in the latest revision of the
Service Table of Limits - SSP-1776
for low
limit and high limit propeller governor idler
gear backlash.
(1)
To complete a check of the low limit backlash, insert
a shim between the spacer and crankcase (Figure
69).
Figure 67
Propeller Governor Idler Gear
Assembly and Thrust Washer
Figure 68
Propeller Governor Idler Shaft
