(3) Remove piston and connecting rod assem-
(4) Remove crankshaft and cylinder sleeves
(refer to paragraphs (a) and (b) above).
(5) Drive camshaft bearings from block. (fig.
14-86. Crankshaft, Cylinder Sleeves, Camshaft
Bearings and Cylinder Block Cleaning, Inspection
(1) Clean crankshaft thoroughly and inspect the
journals for scoring, chipping, cracking, or signs
If crankshaft has been overheated
(usually indicated by discolored or blue bearing jour-
nal surfaces), or is scored or excessively worn, re-
conditioning or replacement will be required. Exa-
mine bearing journals for cracks if overheating has
(2) Measure the crankshaft main bearing and
connecting rod journals at several places on their
diameter to check for roundness. The diameter of
main bearing journals is 3.2465 to 3.248 inches; con-
necting rod journals is 2.747 to 2.7485 inches. The
only recommended method of reconditioning the crank-
shaft is regrinding, as required, to accommodate
Chrome plating or metallizing the
bearing journals is not acceptable.
(3) All main and connecting rod bearing journal
surfaces of the crankshaft are hardened to a minimum
depth of approximately 0.060 inch. If regrinding of
crankshaft journals becomes necessary, the work
should be done by a reputable machine shop that has
suitable equipment to handle precision work of this
type. Main bearing shells 0.002, 0.010, 0.020 and
0.040 inch undersize are available. If crankshaft is
ground, the diameter of main bearing journals should
be reduced in steps of 0.002, 0.010, 0.020, or 0.040
inch below 3.2465 to 3.248 inches to fit the undersize
main bearing shells.
(4) If out-of-round or taper of journals exceeds
0.002 inch, crankshaft must be reground to a standard
undersize or replaced.
(5) Blow out all oil passages in crankshaft with
dry compressed air.
(6) Any bearing shells that are scored, chipped,
pitted, or worn beyond the specified limits given below
must be replaced.
Inspect backs of the shells for
Bright spots on backs of the shells indi-
cate shells have shifted in their supports and are unfit
for further use.
(7) The clearance between main bearing shells
and the crankshaft journals is 0. 0019 to 0. 0046 inch.
New bearing shells must be installed when this clear-
ante exceeds 0. 008 inch.
(8) With crankshaft removed, measure inside
diameter of the bearing at a point 90° from the parting
line, with bearing cap installed and tightened to 170-
Bearing shells when in place are
0. 002 to 0. 004 inch larger in diameter at the parting
line than they are 90° from the parting line, and do
not form a true circle. The two halves of the shells
have a crush fit in their bore in the block and must be
tight when the cap is secured in place. Do not measure
inside diameter at the parting line.
(9) The bore of new main bearings installed is
3.2499 to 3.2511 inches and any reading above 3.2511
inches indicates the amount of bearing wear.
diameter of the crankshaft journal at the corresponding
bearing location and subtract this dimension from in-
side diameter measurement of the bearing (as deter-
mined above); the difference between these two meas-
urements is the crankshaft-to-bearing clearance.
(10) Another method for determining amount of
wear on bearing shells is by measuring each shell with
a micrometer at a point of 90° from the parting line.
New (standard size) shells, should measure 0. 1549- to
0. 1554-inch thick. Bearing shells less than 0. 153-
inch thick are worn beyond the allowable limits and
must be replaced.
(11) The most accurate method of determining
main bearing clearance is by using micrometer, as
described i n the preceding paragraphs. However, if
the proper size micrometers are not available or the
crankshaft is installed in the engine, bearing clearance
must be measured by using a plastic strip manufac-
tured for this purpose.
The plastic strip must be used
in accordance with the manufacturers instructions.
b. Cylinder Block and Cylinder Sleeves.
(1) Thoroughly clean the bores in cylinder block
for the sleeve. Make certain bottom surface of flange
on cylinder sleeve and the counterbore in cylinder
block are clean and free from nicks or burrs.
(2) Before installing the new sleeves, use warm
water and common laundry detergent and scrub the bore
with a stiff bristled brush to insure cleanliness and re-
moval of any possible hone dust from the pores. Dry
and protect with a thin coating of engine lubricating
(3) Before installing packing rings on sleeve, in-
sert sleeve into bore of cylinder block to make sure
sleeve can be pushed down into place and turned in the
bore by hand pressure.
If the sleeve cannot be inserted
and turned in the above manner, more cleaning is nec-
(4) Rotate the sleeve with the contact point of the
dial indicator, contacting the bottom of the counterbore.
Total indicator reading should not exceed 0. 002 inch.
If the total dial indicator reading exceeds the specified
limit, reworking of the counterbore is necessary.
(5) The protrusion (standout) of the cylinder
sleeve flange above the top flat surface of the cylinder