Service Manual

CRANKSHAFT
Clean crankshaft thoroughly and inspect journals for
scoring, chipping, cracking, or signs
of overheating. If
crankshaft has overheated, is scored, or excessively
worn, reconditioning or replacement
will be required.
Examine bearing journals for cracks
if overheating has
occurred.
Measure crankshaft main bearing and connecting rod
journals at several places on their diameter
to check for
roundness and taper.
The only recommended method of reconditioning the
crankshaft is regrinding, as required
to accommodate
undersize bearings. Metalizing of bearing journals is not
recommended.
If regrinding of crankshaft journals is necessary, the
work should be done by a reputable machine shop that
has suitable equipment
to handle precision work of this
type. Undersize main bearings and connecting rodsare
available.
Whenever making major repairs on the engine, always
inspect the drilled passages of the crankshaft. Clean
them to remove any foreign material and to assure
proper lubrication of the connecting rods.
BEARINGS
With camshaft and crankshaft removed, use a micro-
meter to measure diameter of bearing journals. Use a
dial bore gauge or a telescopic gauge and micrometer
to measure inside diameter of bearings. Refer
to
DIMENSION AND CLEARANCES to determine if clear-
ances are within specifications.
Any bearing that is scored: chipped, pitted or worn
beyond the specified limits must be replaced.
Removal of the camshaft bearings requires complete
disassembly of the engine. Use a press
or a suitable
driver to remove bearings. Support casting
to avoid
distortion and to avoid damaging the bearing bore
during removal and installation.
Replacement camshaft bearings are precision type
which do not require line reaming
or line boring after
installation. Clean outside of the bearing and bearing
bore in the block. Before installing cam bearings use
Locktite Bearing Mount on outside diameter of bearing.
Use a combination bearing driver
to install bearings.
Place the bearing on the crankcase over the bearing
bore with the lubricating hole (front only) in the proper
position. Be sure
to start the bearing straight. Press in
the front bearing flush with the outside end of the
bearing bore. Front cam bearing oil hole must line up
with oiling hole in cylinder block (Figure
20). Press in
the rear camshaft bearing
to the dimension shown
(Figure
20). Lubricate bearing surfaces with oil after
installing.
PRESS
0.50
FRONT CAMSHAFT BEARING
BEARING
(12.7 mm)
REAR CAMSHAFT BEARING
FIGURE 20. CAMSHAFT BEARINGS
New crankshaft main bearings are precision type which
do not require line reaming or line boring after instal-
lation. Use a press or a suitable driver to remove
bearings. Support casting
to avoid distortion and to
avoid damaging the bearing bore during removal and
installation.
Before installing main bearings, expand bearing bore by
placing the casting in an oven heated
to 200°F (94°C). If
practical, cool the precision bearing to shrink it.
Before installing the front main bearing, use the towelette
included with the bearing kit
to clean the outside of the
bearing and bearing bore in the block.
prolonged contact with skin can be
Breathing vapor from towelette and
harmful.
Be sure area is well ventilated.
After allowing three to four minutes for drying, apply
the Locktite from the small tube to the mating surfaces
of
the bearing and the bearing bore. Align the oil holes in
the bearing with the oil holes in the bearing bore
(Figure
22). The oil passage should be at least half open.
Install the bearing flush with the block, using the
combination driver. Wipe
off excess Locktite around the
bearing. Allow at least one hour for hardening at
room
temperature.
10-13