DETROIT DIESEL 53
CRANKSHAFT OIL SEALS
the oil seal bore. Then press or drive the oil seal out of
An oil seal is used at each end of the crankshaft to
the front cover or the outboard hearing support.
retain the lubricating oil in the crankcase. The sealing
Discard the oil seal.
lips of the oil seals are held firmly, but not tight.
against the crankshaft sealing surfaces by a coil
2. Support the forward face of the flywheel housing on
The front oil seal is pressed into the lower front cover
on two wood blocks next to the
engine (Fig. 1 ).
oil seal bore. Then press or drive the oil seal out of the
housing. Discard the oil seal.
3. Clean the oil seal bore in the front cover, outboard
bearing support or flywheel housing thoroughly before
A single-lip oil seal is used at the rear end of the
installing a new oil seal.
crankshaft of most industrial engines. A double-lip oil
seal is used in engines where there is oil on both sides
When necessary. an oil seal may be removed without
of the oil seal; the lips of the seal face in opposite
removing the front cover, outboard bearing support or
directions. The rear oil seal is pressed into the flywheel
flywheel housing. This may be done by drilling
housing (Fig. 2).
diametrically opposite holes in the seal casing and
threading metal screws, backed by flat washers, into
Oil leaks indicate worn or damaged oil seals. Oil seals
the casing. Remove the seal by prying against the
may become worn or damaged due to improper
washers with pry bars.
installation, excessive main bearing clearances, exces-
sive flywheel housing bore runout or grooved sealing
surfaces on the crankshaft. To prevent a repetition of
any oil seal leaks, these conditions must be checked
Inspect the front and rear end of the crankshaft
Remove Crankshaft Oil Seals
for wear due to the rubbing action of the oil seal, dirt
build-up or fretting caused by action of the flywheel.
Remove the engine front cover (Section 1.3.5),
outboard bearing support or the flywheel housing
(Section 1.5) and remove the oil seals as follows:
1. Support the forward face of the front cover, or the
outboard bearing support, on two wood blocks next to
Fig. 2 . Crankshaft Rear Oil Seal (In-Line
Fig. 1 - Crankshaft Front Oil Seal
SEC. 1.3.2 Page 1