IO-390-D Series Engine Maintenance Manual
72-20
© 2020 Avco Corporation. All Rights Reserved
Page 180
March 2020
IO-390-D Series Engine Maintenance Manual
(6)
Spread the excess sealant smoothly
over the oil seal and crankcase
(Figure 93)
(7)
Let the Dow Corning
®
737 Neutral
Cure Sealant to cure for 24 hours.
Figure 93
Spread the Excess Sealant
B.
Install a split oil seal (Figure 47) in the crankcase as follows:
(1)
Apply a thin film of Lubriko M-6 grease or equivalent on the sealing surface of the seal
and around the crankshaft at the sealing surface.
NOTICE:
If Pliobond
®
#20 or Pliobond
®
#25 is substituted for Dow Corning
®
737 Neutral
Cure Sealant, refer to the manufacturer’s instructions for application details and
cure time.
(2)
Apply a coat of Dow Corning
®
737 Neutral Cure Sealant to the split of the seal.
(3)
Face the propeller end of the crankshaft and assemble the split oil seal with the split at the
1:00 o'clock position (11:00 o'clock position for left-hand rotation engines) with the front
face of the seal toward the crankshaft propeller flange.
CAUTION
DO NOT APPLY MEK SOLVENT TO THE CRANKSHAFT OIL
SEAL SINCE MEK CAN CAUSE THE SEAL TO DETERIORATE. BE
SURE THAT ALL TRACES OF CLEANING SOLVENT, OIL AND
SEALANT ARE REMOVED PRIOR TO INSTALLATION OF A NEW
CRANKSHAFT OIL SEAL.
(4)
Use ethyl alcohol and disposable wipes to clean the outer surface of the split oil seal and
the crankcase seal bore recess. Make sure nothing comes in contact with the cleaned
surfaces.
CAUTION
USE A BRUSH AND BUTYL RUBBER GLOVES WHEN APPLYING
SEALANT AND INSTALLING THE OIL SEAL (FIGURES 92 AND 93).
NOTICE:
In the next step, do not get sealant on the crankshaft. If any sealant gets on the
crankshaft, use acetone to remove all traces of sealant.
(5)
Apply a liberal coating of Dow Corning
®
737 Neutral Cure Sealant to the outside
diameter of the split oil seal (Figure 92) to allow the excess sealant to squeeze out
between the crankcase and the oil seal when the oil seal is installed.
(6)
Press the split oil seal firmly against the seat in the crankcase bore. Apply pressure all
around the seal until it is firmly seated in the bore.
(7)
Spread the excess sealant smoothly over the oil seal and crankcase (Figure 93)
(8)
Let the Dow Corning
®
737 Neutral Cure Sealant to cure for 24 hours.
