Propeller Governor Drive Installation (Engines With Front-Mounted Propeller Governor Drives) - Lycoming IO-390-D Series Maintenance Manual

IO-390-D Series Engine Maintenance Manual
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)
• Governor gasket
• Idler gear gasket
Thrust Washer Part Number
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).
© 2020 Avco Corporation. All Rights Reserved
March 2020
• Dowel pin (smaller)
• Set screw
Thrust Washer Thickness
73249
73250
73251
73252
01L21418
• Thrust washer
(different thickness sizes available - Table 2 - requires
measurement of clearance in subsequent steps to
identify the correct thrust washer)
Table 2
Thrust Washer Thickness
in.
0.0585 to 0.0595
0.062 to 0.063
0.0655 to 0.0665
0.069 to 0.070
0.055 to 0.056
Propeller Governor Idler Gear
Propeller Governor Idler Shaft
mm
1.4859 to 1.5113
1.575 to 1.600
1.6637 to 1.6891
1.753 to 1.778
1.397 to 1.422
Figure 67
Assembly and Thrust Washer
Figure 68
72-20
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