IO-390-D Series Engine Maintenance Manual
© 2020 Avco Corporation. All Rights Reserved
72-20
March 2020
Page 161
IO-390-D Series Engine Maintenance Manual
D.
Solid-Ring Crankshaft Oil Seal Installation
NOTICE:
Install a
new
crankshaft oil seal during crankshaft assembly. There are two types of
crankshaft oil seals: a split oil seal (Figure 47) and the solid-ring stretch oil seal
(Figure 48). The split oil seal is open for easy assembly around the crankshaft. The
solid-ring oil seal has more elasticity and can be stretched over the crankshaft
propeller flange. The solid-ring oil seal can be installed on the crankshaft
before
or
after
the crankshaft is installed in the crankcase. The split oil seal is installed
after
the crankshaft is installed in the crankcase.
Figure 47
Split Oil Seal
Figure 48
Solid-Ring Oil Seal
NOTICE:
An oversize crankshaft oil seal could be necessary if the crankcase bore size was
increased. Part numbers for oversized parts include a “P” suffix, such as –P10 and
are identified on the face of the seal. Except for the revised outside diameter of the
seals, the oversize seals are identical in other aspects to the standard size seals.
For correct sealing remove all traces of the oil sealant and oil from the crankcase
before a new crankshaft oil seal is installed.
(1)
Solid-Ring Oil Seal Installation
(a)
If not already done, complete the “Starter Ring Gear Support Removal” procedure in
Chapter 72-70.
(b)
Examine the propeller flange, crankshaft sealing surface, and the crankcase seal bore
recess for any scratches or nicks that damage or cause the seal to leak; if found, remove
with fine emery cloth (150 to 220 grit for very light metal sanding) or equivalent small
fine abrasive stone. Remove any residue.
CAUTION
ONLY APPLY MEK SOLVENT TO THE CRANKCASE, INCLUDING
THE CRANKCASE BORE AND GROOVE FOR THE CRANKSHAFT
OIL SEAL. 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.
(c)
Clean the crankcase bore, use a clean disposable lint-free cloth and any of the following
cleaning solvents to remove oil, sealant, and debris from the crankcase, especially the
crankcase bore which has the groove for the crankshaft oil seal:
•
Methyl-Ethyl-Ketone (MEK)
•
M-17
•
Acetone
•
M-114.
•
Napasco SC-200
