together with lower halves of
(10) Remove front filler block (22) and seal
by taking out two bolts and washers.
(5) Insert a bearing-removing tool through
(11) Punch-mark the main bearing caps
oil-hole in crankshaft journal. Rotate
and the cylinder block to assure
crankshaft by hand so that tool forces
correct installation (fig. 11).
upper half of bearing out of
(12) Remove lock wires and take out two
Be sure to turn the
bolts and washers from each cap (11,
crankshaft so that the lock (stamped
12, 13, and 14, fig. 4). Note punch
ear) on the bearing half is raised out
marks on bearing caps (fig. 11).
of its notch. Repeat for all bearings.
(13) Lift bearing caps off dowel pins
Do not ream, scrape, or burnish
(14) Lift out the crankshaft and press off
crankshaft bearings. Replace bearing
crankshaft timing gear if necessary.
halves in pairs if they are in any way
b. Inspection and Service.
(1) Mount crankshaft in V-blocks, and use
(7) Coat new bearing halves with OE and
dial indicator to check alinement.
insert in same number as old halves
(2) Measure crankshaft journals at opposite
points at several plac, using a
Crankshaft bearing clearance
micrometer. Replace crankshaft if
should be checked after new bearings halves have been
taper or out-of-round at journals
installed. Measurement should be taken with seals
exceeds 0.001 inch.
removed. The main bearing clearance should be 0.001
(3) Inspect crankshaft oil passages Make
to 0.0032 inch.
certain that they are free and
(1) When checking a bearing for clearance,
unobstructed. Clean with compressed
all other bearings must be installed
air and wire brush, if necessary.
with caps tightened firmly in place.
c. Installation. Reverse procedure in a above.
(2) Remove bearing cap and place a piece
Tighten connecting rod nut to 35 to 40 foot-pounds
of 0.002 by ½ by 1-inch shimstock in
torque and crankshaft bearing capscrews to 85 to 90
bearing cap (fig. 12).
(3) Install bearing cap and tighten to 85 to
d. End Play. After crankshaft has been installed,
90 foot-pounds, using a torque
mount a dial indicator against some vertical surface of
wrench. If crankshaft rotates with a
the crankshaft, and use a pry bar to move the crankshaft
noticeable drag, clearance is correct.
back and forth. Use the indicator to measure the end
Clearance may be checked by
play. Normal end play is 0.005 inch to 0.009 inch. If
plastigage method if plastigage and
end play is excessive, remove the front main bearing;
special measuring gage are available.
replace it with a new one and check end play again.
If this method is used, do not rotate
crankshaft with plastigage in place.
28. Crankshaft Bearings
Fitting Crankshaft Bearings.
crankshaft bearing caps if original caps have become
a. Replacement. The engine is equipped with
damaged or broken. Do not file, dress down, or shim a
sleeve bearings which may be replaced in the manner
bearing cap (crankshaft or connecting rod) except when
and order indicated below without removal of the
installing a replacement cap, and then only for its
original installation in the engine. Replacement caps
(1) Remove engine from truck (par. 12a).
conform to original caps in every respect, with the
(2) Remove oil pump (par. 16a) and inlet
exception of stud holes which are 1/64 inch larger, and
and outlet pipes.
bearing cap size which is 1/16 inch shorter. The caps
(3) Remove spark plugs if cylinder head is
must thus be properly fitted by shimming or filing to
obtain bearing clearance.
(4) Remove crankshaft cap bolts, and
remove crankshaft bearing caps