SIX
CYLINDER
ENGINE
6-25
Fig.
6-46
Removing
Upper
Rear
Main Oil
Seal
seal (Fig. 6-46) until it protrudes far
enough
to be
removed with pliers. Push new seal into place.
NOTE;
Avoid
scraping
seal on edge of cap and
block
seal locating grooves.
7. Install bearing cap using J
22325
(Fig. 6-44) and
torque bearing cap
bolts
100 lb. ft.
8. Install oil pan. Do not overtighten.
MAIN
BEARINGS-REMOVE
AND
REPLACE
The
main bearings are of precision insert type and
do not utilize shims for adjustment. If the clear-
ances are found to be excessive, a new standard or
undersize bearing insert, both upper and lower
halves,
will
be required.
NOTE:
To replace the upper
half
of the
rear
main
bearing,
it
will
be necessary to loosen all main
bearing
caps. Slowly rotate the crankshaft and
force
bearing out with a
putty
knife or similar tool.
REMOVE
1. Remove oil pan. (See - "Oil Pan - Remove and
Replace".)
2. Remove cap on main bearing requiring replace-
ment and remove bearing from shell.
3.
Install a main bearing shell removing and in-
stalling
tool
such as KMO 734 in the oil
hole
in the
crankshaft.
NOTE:
If such a tool is not available, a cotter
pin
may be bent as
required
to do the jo
b
(Fig.
6-47).
4. Rotate the crankshaft clockwise as viewed from
front of
engine.
This
will
roll
upper bearing shell
out of
engine.
REPLACE
1. Oil new upper bearing shell and insert plain
(unnotched) end of shell
between
crankshaft and in-
dented or notched side. Rotate the bearing into
place.
2. Install new bearing shell in bearing cap.
3.
Check bearing clearance using Plastigage
method as outlined below.
4. Install oil pan using new gaskets and seals.
PLASTIGAGE
METHOD
OF
DETERMINING
MAIN
BEARING
CLEARANCE
1. Place a .002" brass shim
between
the crank-
shaft journal and lower bearing in each bearing cap
next to that being checked. Tighten all cap
bolts
to
100 lb. ft.
This
causes the crankshaft to be forced
against the upper bearing and insures an accurate
measurement of total clearance.
2. Remove the bearing cap of bearing to be
checked. Wipe bearing and journal free of oil.
3.
Place a piece of Plastigage, the length of bear-
ing (parallel to crankshaft), on journal or bearing
surface (Fig. 6-48). Install cap and tighten cap
bolts
to proper torque.
NOTE:
Do not turn crankshaft with Plastigage in
place.
4. Remove bearing cap and using Plastigage scale
on
envelope
measure width of compressed Plastigage
before removing it from the bearing or journal (Fig.
6-49). If bearing clearance is
between
.0003" and
.002", the clearance is satisfactory. If clearance is
more than .002", replace bearing with next under-
59°
Fig.
6-47
Tool
For
Removing
Upper
Half
of Main
Bearing
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